View Full Version : Auto engine marinization


06-10-2002, 06:29 AM
Hi. Can anyne help me find resources (preferably on the net but any will do) on how to marinize an auto engine. I know of one book that describes the process but it is out of print and difficult to get hold of. Any help appreciated.

Jeff
06-10-2002, 07:56 AM
The questions to start with would be gas or diesel, salt or fresh water?

I'm not a mechanic, but here is a repost of a usenet message which Rod McInnis posted in response to a similar question - there must be a few how-to's on the Internet but I don't have links off-hand - spending an hour or so with Google is probably a good bet:

Do you want it to be legal? Do you want it to be safe? Do you want it to last a long time?


The longevity is an issue with the raw water cooling, especially if the boat will ever see salt water. An automobile engine is cooled with, preferably, antifreeze, but even straight water will neutralize itself and stop eating away at the metal parts. On a boat, you have a constant flow of new water, which leads to a higher rate of corrosion. Two areas that are usually "marinized" are the head gasket and freeze plugs. If you are rebuilding the engine anyway, get the marine head gasket, and make sure the freeze plugs are brass instead of steel.


Safe and legal are mostly fire/explosion issues dealing with the fuel and electrical system.

FUEL:

The marine carburetor will be a little different, designed so that the float bowls don't vent into the engine compartment, although the differences are rather subtle (at least to my eye).

The fuel pump has one major difference: it is designed to contain the fuel in the event of a ruptured diaphragm. It is common for a fuel pump to fail by rupturing the diaphragm, which allows gas to leak onto the side where it wasn't intended to be. This gas will then either leak out onto the ground or into the crankcase. For a car, onto the ground is preferred, but on a boat either case is really, really bad! A standard solution to this problem is to have a double diaphragm, with a drain between them. If the primary diaphragm ruptures, the gas will be contained by the second diaphragm and flow out the drain. This drain typically has a hose (usually clear) attached to it which leads up to the carburetor intake. Any gas that leaks is dumped into the carb, and if the leak gets bad enough it will flood the engine, which is a lot better than blowing you to smithereens!


ELECTRICAL:

Starter, alternator: rotating shafts with electrical contacts, they make sparks! Sparks will ignite fumes! To prevent the sparks from blowing up the entire boat, a marine starter and alternator will have flame suppression on the cases. The starter and alternator are NOT sealed, they have what is essentially a flame arrester between the source of sparks and the outside. It is possible for a small amount of gas fumes to enter the starter/alternator and be ignited, but the case will hold the small explosion and the flame arrester will prevent the fumes in the boat from being ignited. This flame arrester may look like nothing more than a small screen, but it is so important!

Distributor: Same flame arrester idea as the starter. The advance curves for an automobile are usually not the best for a boat, so you are better off with a marine distributor anyway.


While the fuel system modifications are intended to prevent any combustible fumes from being accumulated, the electrical system is designed to not ignite any such fumes that might be present. You may consider it redundant, but there are other ways to get gas fumes in
(such as while refueling) and other sources of ignition.

I highly recommend that you purchase the marine versions of the starter and alternator. You may choke when you see the price tags, but consider this: gas fumes are heavy, they settle to the bottom. The starter is located about as far down as anything can be. Gas fumes are most likely to settle when the boat is idle, which means that the starter is most likely to be the first electrical item operated. Starters, with out a doubt, make sparks. In other words, the greatest hazard comes from the starter.

Rod McInnis

And another:

Hi...

I had a target engine (off the shelf from a dealer) rebuilt when it spun a bearing. The rebuilders used a different cam (for the nature of the use rather than highway), racing timing gears and chain (usual higher revs than automotive) and brass vs. steel freeze plugs.

Dropping in the marine electronics (mine was carb, so your application might be different) including the brain and distributor (no spark) completed the deal. Runs like a champ.

So, there's not all that much different. If you don't already have the exhaust manifolds, that will be extra, but isn't really marinizing the 'engine' - and you'll want the marine alternator and starter, probably, too, for the same no-spark reasons. So, all the "hang-on"s will likely have to be bought new or used, but the engine itself doesn't need much modification.

Skip.

Jeff
06-10-2002, 08:21 AM
And some other on-topic posts from rec.boats.building over the past year:

From: John

It can be done since Merc, OCM and Volvo do it all the time. Remember to:
1. Change to Brass freeze plugs
2. Change the Alternator, Starter and Distributor to their respective Marine Versions
3. Change the Air Filter to a USCG Flash suppression type.

From: Bryon Kass

Also add change camshaft, circulator pump, head gaskets, thermostat, carb, intake and exhaust manifolds, bell housing, flywheel, and anything else I forgot. Bryon Kass webmaster and Custom Design
150 Mechanic St. Foxboro, MA 02035
508-543-9068 or fax 508-543-5127, Foot yard 508-384-2415 in THE ENGINE ROOM http://getit.at/engineroom

From: Stephen G. Lusardi

Justin, I'm not sure of you're engine knowledge or skills, but be advised that this task can only be done by very knowledgeable, experienced people or you will have lots of trouble. The following points must be observed.
1) A car engine is a LIMITED duty engine and a marine engine is a continuous duty engine.
2) There are many differences in the following: a. Ignition advance curve b. Valve timing (camshaft) c. Oiling system d. Cooling system. e. Exhaust system f. Carburetor g. Air cleaner h. Alternator I. Starter Please remember when it breaks, you cannot call AAA for service. You become a burden on others, give boating a bad name and risk lives unnecessarily. Please be responsible and do this correctly. Steve

From: Augusto Queiroga Valentim If you do you will regret it........sooner or latter! Probably rather soon. Boats demand a lot of power, and automobile engines are not engineered for continuous full power duty, as marine engines are.

From: Vacuo

It is always assumed that the auto engine installed in a boat is going to be operated at WOT ( wide open throttle) since this fits the behavior pattern of most boaters. But there is no reason why an oversized engine cannot be installed instead, say 2 or three times the displacement. Thus the auto engine can loaf along at 2500 rpm which is near the peak of its torque curve, and thus enjoy maximum fuel efficiency. With the right choices the available power at this rpm will be just what the boater requires.

Thus, a Rabbit diesel is the equivalent of a 20 to 25 hp marine engine- no more. Fine for propelling a sailboat or other displacement hull.

Vacuo

From: Marcus G Bell

Right. When an auto engine is marinized, it's peak HP rating is derated by a fraction. Also, many boaters "cruise" at less than WOT.

The auto engine uses something like 25% of its rated HP to keep the car moving at steady highway speeds. The marine engine very often is cruised at 50-75% of its rated power, which corresponds to something like 33-50% of the peak power of the "same" engine rated for land use.

So a marine engine works harder than a car engine, but it is more steady work than experienced by the auto engine upon which momentary high loads are placed.

-- -- Marcus.

From: John

Marcus Iam trying to figure this out, What is the exact difference between a Marine engine and an auto engine of the same displacement by the same manufacturer other than the obvious (Freeze Plugs, Starter, Distributor ect.) Lets take the Chevy 305 V8 which is used by Merc and Volvo. What are the other difference? If I had to guess I would say the cam is different maybe the heads but what else? In addition I believe that the blocks used are base on truck blocks rather than car blocks.

From: Stephen G. Lusardi

Marcus, There are many differences between a limited duty engine and a continuous duty one. As an example , it is necessary to understand the difference between an SAE work test and a standard BRAKE test. Both tests are performed on the same device called an engine brake or engine dynamometer. Essentially the engine is run up against a variable load. This load device is mounted in bearings so it can rotate, but it is prevented from rotating by a lever which is attached to a scale. This scale will read out in ft. lbs.. So at any engine speed the maximum torque can be read. Because torque is one component of horsepower and speed being the other, horsepower can be calculated as well as fuel consumption, brake mean effective pressure and a number of other items. The important thing is the test program. A BRAKE test is where the engine is warmed to normal operating temperatures and then run up to maximum power and that's the end of the test. An SAE test, on the other hand is run up against the load for a sustained period (maybe 4 hours) until the maximum power is reached that DOES NOT exceed acceptable manufacturers operating parameters like oil, water, exhaust and head temperatures and pressures. In your example you mentioned the Chev. 305. This engine will brake somewhere around 220 to 280 HP depending on state of tune. The maximum SAE rating of this engine is 55 HP.

I suggest that if you were flying on a plane, or on an ocean cruise ship, you would want the engines tested under an SAE test program. The differences in design and build are many. Intelligently, you have to factor the type of usage you need from the engine and then modify the automotive engine accordingly. The greater the durability, the greater the cost. Nothing is for free and when a marinized automotive engine costs are comparable to the standard automotive variety, you must question it's durability. Steve

From: bro

i have a 1972 buick 455 that i plan to put in a 18 ft flat bottom v-drive so far i have chnaged the freeze plugs to brass and i am changing all bearings and gaskets but what should i do on the camshaft ??? thanks jon

From: Stephen G. Lusardi

Jon, The Camshaft should be the least of your concerns. If you intend to to be able to run this engine at more than 1/2 throttle for any length of time, your biggest problem is cooling. Automotive engines do not cool evenly when under heavy load. If you check the water flow diagram for your engine you will see that cool water enters the engine in front by the pump, proceeding rearward gaining heat eventually exiting the block through the steam riser holes into each head between each cylinder. Then the water runs forward within the head exiting to the intake manifold, then the thermostat housing and then back to the radiator. The net effect is that the front cylinders get more cool water than the rear. The two center cylinders have less surface area for cooling as well, so run hotter than the ends of each bank. Continuous duty engines and long track NASCAR engines are modified so that there is a water distribution log mounted on each bank in the lifter valley, under the manifold in an attempt to even the cooling a bit. They run forged crankshafts, cored con rods for spray oil cooling of the bottom of the pistons and many other refinements that have little value when running in a limited mode, but have extensive value when running in a continuous mode. They have high temp. resistant stainless steel valves, stellite valve seats, better guides and oil seals. They use low cam lobe acceleration rates, wider valve centers typically 112 degrees as opposed to performance cams at 106, lighter valve springs to save effort and stress on the valve train. They use thermostatically controlled oil coolers, larger volume oil pumps, larger oil filters that are also incidentally full flow and the list goes on. If you are going run in circles on a lake, carry a set of oars and have little regard for repair costs, I guess these changes are of little value to you. If however your needs are a bit more stringent, please consider a proper marine engine.

From: SAIL LOCO

<<<<<<<The Camshaft should be the least of your concerns. If you intend to to be able to run this engine at more than 1/2 throttle for any length of time, your biggest problem is cooling. Automotive engines do not cool evenly when under heavy load. If you check the water flow diagram for your engine you will see that cool water enters the engine in front by the pump, proceeding rearward gaining heat eventually exiting the block through the steam riser holes into each head between each cylinder. Then the water runs forward within the head exiting to the intake manifold, then the thermostat housing and then back to the radiator. etc. etc.>>>>>>>

I have never seen any engine where the water flows to the heads last. Water always goes to the heads first since that is the hottest part of the engine. The water in every engine enters at the water inlet on the intake manifold and imediately enters the heads water passages.

From: Marcus G Bell

Many, if not most auto engines have the water leaving the bottom of the radiator and entering the pump first. The pump then delivers the coolant to the bottom of the block. Half of the pump volute is often cast integral with the block, and the main pump outlet is then a passageway cast directly into the block's water jacket. A small hose delivers some flow to the intake manifold and the manifold drains into the head, but the bulk flow to the head comes upwards from the block. The thermostat is in the top of the head and the hot fluid leaves the engine through the thermostat.

The flow of coolant through the engine and radiator follows the direction of natural convection. Hot fluid comes into the top of the radiator where it cools and falls, then flows into the bottom of the engine where it heats and rises. The pump assists the convection. It is the rare consumer-grade automobile engine which operates in opposition to this convection, and I know of none of the top of my head. So, I find the statements "Water always goes to the heads first" and "water in every engine enters ... the intake manifold" to be misleading and/or incomplete.

-- -- Marcus.

From: KPB314159

I don't know where this thread started, but I can tell you I have seen many converted auto engines spread out on a dock, waiting for delivery of some replacement frammitz. Most of the problems that could be categorized fell into the cooling area: cracked manifolds, cracked heads, carbon and other problems from running too cold, etc. One common problem is that if things are misadjusted it is possible to shoot very cold lakewater or seawater directly to a hot engine which would never be expected by the designers of an automotive engine. Ken Bowen

From: Wallace Waggoner

Original thread revolved around the differences auto vis marine engines. Does anyone really believe GM has a seperate dision building differnent components for its 5.7 sold to Volvo and Mercruiser? Of course not. You can purchase a parts list for any Ford or Chevy based Marine engine from your local car/truck dealer. Check it out for yourself and see if you can justify the price charged for your boat engine. Marine manufactures have a sweetheart deal with Ford/Chevy. You and I can not go to a dealer and purchase one of their marine longblocks for $2200. You must purchase in the quantity of Redline et al and be a "certified" OEM marine engine builder.

The Marine Industry has been pulling the wool long enough. In the are Its even worse regarding diesel and outboards.

Wally

From: Wallace Waggoner

Outside water-cooled exhaust and the optional FWC Volvo and Mercruiser by a GM engine changed very little from the new engine you purchase from a dealer to put in your car.

Talk to any performance engine builder in your area. He has catalogs for any parts you need for a long block put to marine use. Stellite seats will cost you abbout $8 and stainless valves another $8 a piece. Another $20 for better grade of Clevite bearings.

A marine engine needs low end torgue. You get this by NOT spending huge quantities on high performance heads and trick cams. Standard reliable parts and machining are key. Obviously a few more dollars in incresed cost of Coast guard approved and mandated parts.

Wally

From: krulik

This is all well and good but what are the differences in the construction of the engine. Using that Chevy 305 again, Now, If I change the rear end gear from a 3:23 to a 4:11 that will increase the amount the engine will have to work to maintain the same speed what other changes are needed to the engine? If marine engines can sustain more revs with a greater load they should be used in auto racing? Seems that this would be the next logical step.

From: plkruse@iu.net

I've found this thread to be especially interesting, especially the parts of it that deal with the power ratings of the engines. I'm much more familiar with diesel engines than with gasoline ones, (such that I can quote the spec's of some of the more common ones without having to look them up). So, the examples that I will site pertain directly to diesel engines, but the exact same principles apply to gasoline engines. In fact, I?ll use the CAT 3208 as an example, since it is a V-8 diesel very similar to a large gasoline engine. (636 cid)

The harder you run an engine, the faster you will wear it out. It really is as simple as that. Every engine therefore has many different power ratings, depending upon how hard you plan to run it and how long you want it to last. If I were to tell CAT that I was going to put the engine into a small commercial fishing trawler that was going to run 3500 hours pre year, for example; then they would tell me that the 3208 was good for 150 hp. They would derate the engine so that I could not get more than that much power out of it. If you were then to ask them for an engine for a high performance recreational boat that was not going to be used more than 300 hours per year, then they would tell you that the same engine was good for
435 hp.

What?s the difference between these two identical engines, that they would have such a different rated power? Chiefly this: In both cases CAT wants for the engine to last at least as long as the warranty. Since I?m going to put a whole lot more hours onto my hypothetical boat than you are, they will derate mine in order to achieve that objective. In another example, I was once going to put a CAT 3412 into an air boat. My customer wanted the most power for the weight and the cost, but was happy with an engine life of at least 1800 hours. This is a very unique case, in which CAT was willing to rate the engine at 1000 hp. On the other hand, a friend of mine maintains a fleet of work boats with this same engine in them. He runs them at about 500 hp and gets 50,000 hours between overhauls.

CAT has five different power ratings published for each engine. (If you present them with a special case, you will learn that they actually have more ratings than that.) These ratings go from "A" for continuous duty to "E" for highly intermittent duty. In this example, the A rating for a 3208 is 150 hp; whereas the E rating is 435 hp. Gasoline engines have a similar ratings system, except that the DIN and ISO standards for "automotive power" ratings will give you a slightly higher number than most "highly intermittent" ratings. In other words, it is the peak power you might use if you were passing uphill. It is certainly not the amount of power that you can expect the engine to put out for any significant period of time.

We are currently building two boats, both commercial fishing work boats; and are about to buy an engine for one of them. It will most likely be a Cummins B5.9 in one of its many versions. This is the same engine Ford used to offer in their pickup trucks, and Dodge currently offers. Cummins is telling me that they will rate it for
150 hp in our boat, but it is rated at 220-250 in its various automotive applications, and it is offered in a 300 hp version for recreational marine uses that do not exceed 300 hours per year. To put this into perspective, a pickup truck running flat and level at 75 mph without a trailer will require about 50 hp. The same truck with perhaps a 10,000 lb. gross load would require most of the 220 hp. The same engine in a 25 foot sport fishing boat would probably cruise at about 200-230 hp.

There is a difference between the way commercial truck engines and car engines are rated. (A pickup truck is a car for the purposes of this discussion.) In the case of a diesel truck engine, they are rated pretty much at the power they are operated at. In a gasoline car engine, however; they are rated much higher than you would ordinarily ever use them. I know of another example that illustrates that point nicely. They are two almost identical 35 foot sport fishing boats that typically run over a 100 miles off shore together, where they troll for deep water fish. One has twin Cummins 6B5.9 engines salvaged out of pickup trucks and converted to marine use. The other has twin 454?s, also salvaged out of automotive service and converted. All four of these engine are rated at 250 hp, or within five percent of it. These boats normally stick close together all weekend, until it is time to run home; at which time the diesel boat will beat the gasoline boat home by about six hours. The difference is that Cummins recommends that the diesel boat back off of maximum rpm by only 200; whereas no one is going to run a gasoline engine that hard for that long. That captain backs off about a thousand from maximum rpm. To exceed that speed for long periods of time causes cooling problems. This is very consistent with the way the engines were designed to operated during their first lives as automotive engines.

To sum it all up, an automotive engine will typically run at 20-40 percent of its rated power. (In this case, I?m using "automotive power ratings.") It will only exceed these limits under highly unusual circumstances. If you put the same engine into a recreational boat, it will typically run at 60-80 percent of its rated power. A commercial diesel truck engine typically runs at about 60 percent of its rated power. (Flat, level, 75 mph, maximum legal gross load.) That same diesel engine installed into a recreational boat will often run at up to 95 percent of its rated load, with bursts perhaps as high as 105 percent. If these same engines are installed into commercial work boats, then their service lives would be more similar to the truck or the car. It is all a matter of how long you expect to run your engine before replacing it or overhauling it.

All the numbers I quoted in this article are from my memory. If I were at work, where I have all my reference books, I would have checked them more carefully. They should be fairly accurate, and are certainly good enough for the comparison purposes for which they were intended. Since the same engine is sold in so many different versions, you would certainly want to check the OEM specifications on your particular engine before making any critical decisions based upon these numbers.

From: Rick Morel The above really says it all. I'm more familiar with auto engines used in aircraft, but this is very much like marine use. Except it's a lot easier to drop the hook and look for a tow than start looking for a possible landing site! Know what the prop on an airplane is for? To keep the pilot cool -- turn it off and watch him sweat!

Aircraft engines are much derated for reliability. The old Continental
65HP was used in racers at about 120HP, for a life of a couple hundred hours instead of a couple thousand.

VW engines have been used a lot. In the car, they're rated at about
60HP for the 1,600cc. In planes, if they're derated to 40-45HP, they seem to last forever. If used at 60HP a few hundred hours. Then there are the "high HP" conversions, claiming 85 and more. The life of these seem to be in minutes!

My brother used to build dragsters years ago. He'd get 1,800HP out of Chevy 454.... for three drags. About 30 seconds.

I think someone mentioned a Subaru engine in this thread. The
4-cylinder and 6 have been used on gyroplanes with good results. I forget the spec HP rating for the 4, but used at about 50HP makes for a very reliable and long-lived engine.

To maybe put things in some perpective, the VW is rated at 5,200 RPM, if I recall right, but is set up in aircraft for 3,800 RPM take-off and about 3,600 RPM cruise. The Subaru 4 has I think the same spec RPM, but is used at 4,000 and 3,800.

One more question I remember was how much HP does an average sedan take for 60 MPH? Now, getting to my EV (Electric Vehicle) period. My Electric Ford Escort Wagon took 12.5 HP for 55 MPH. A Ford Ranger pick-up requires 19.2 HP for 55 MPH. Less than we would think. The big difference in HP required (and gas/electron milage) is due almost all to aerodynamics.

Rick

From: plkruse@iu.net

[much good aviation comparisons snipped]

A good way to approximate the amount an engine puts out under any given set of circumstances is fuel consumption. Figure a diesel engine burns about one gallon per hour per 20 hp. The number for a gasoline engine is about 15. These numbers can vary quite a lot for certain applications, but they are good general numbers.

By them, my Honda Civic requires about 22 hp @ 60 mph, and 34 hp @ 75 mph. My dad's F250 (3/4 ton Ford pick up truck), requires 60 hp @ 60 mph when running empty; and 104 hp at the same speed when fully loaded with his 30 foot RV trailer.

I know a heavy recreational passagemaker-trawler (49 ft) that requires
60 hp at 7.5 knots. By the same reckoning, a 25 foot sport fishing boat running at full speed with the same engine requires 300 hp. I've got the same engine, a CAT 3208, in a piece of heavy equipment at work, and it averages about 175 hp. Message 36 in thread From: Mike Goodwin (panmanii@pinn.net) Subject: Re: car engine conversion Newsgroups: rec.boats.building View this article only Date: 1999/05/26


I take it that this is done with the governor on a diesel to limit RPM's , how is it done in a gas engine?

From: plkruse@iu.net

Actually, that is not how it is normally done in a diesel engine. Rather, you will likely find different injection pumps, different injectors, and different computer settings in different engines of the same type that are rated at different power levels. Most often, you will find two engines rated at different power levels to actually run at the same rpm shaft speed, but sometimes the higher rated engine will run a little faster. In some such cases, the moving parts will be better balanced in the faster turning engine; and may even be made of a lighter alloy; but in most cases nothing is done inside of the engine when they are rated at higher shaft speeds.

Another way that is often used for both gas and diesel engines is to control how they are used. A particular boat may be geared and proped such that it can only put a 200 hp load onto an engine at 2800 rpm, for example; whereas the same boat owned by someone else could be geared and proped to place 300 hp on the same engine.

As for how to "dump down" a gasoline engine, I guess that the carburetor or the fuel injector would be the easiest place to do so without putting a higher parasitic load onto the engine. If the engine is computer controlled, then that may also be used, just like with some diesel engines.

From: plkruse@iu.net

They were fairly standard conversions; basically the same thing that you would have had if you where to buy the marine version of either one of these engines. They both had wet marine exhaust manifolds and heat exchangers fresh water cooling. The gasoline engines had the "fire proof" marine carburetor, distributor, alternator, and starter; as well as a flame arrestor on the carburetor. I don't know what cams they might have had in them; and I'm pretty sure that the heads and pistons were original.

If you have a high interest in this, then I'd suggest picking up a copy of "Inboard Motor Installation," by Glen L. Witt and Ken Hankinson. It is available through Glen-L Marine Designs, 9152 Rosecrans, Bellflower, CA 90706. The ISBN is 0-939070-01-4. They cover the subject in good detail that is easy to understand. This includes not only the engine itself; but also every aspect of how to install both it and the transmission.

From: Credence Vision Systems LLC

Truly 'marinizing' motors starts on the design table. The differences go right through the whole engine: Large (sometimes roller type) main bearings on the crank shaft between every 2 connecting rods, different stroke on the motor (more torque at lower rpms), different compression ratio (lower), different cam, different carburetor etc. They take the same basic motor as what is produced for a car, beef up the bearings and make small adjustments to bring the horsepower and torque curves a little lower on the rpm curves. Externally, there are tons of differences intended to make the motor fit in a tight compartment, sometimes use a generator instead of an alternator, and the cooling system is redesigned around the new motor. Go to a boat show and look at the 'Vortec' Chevy engines designed for marine use. Nothing like the 'Vortec' Chevy engines that go in cars, except maybe the block/heads/valve covers and the like are the same.

I'm not sure what 'marinizing' would mean after the fact on a motor, e.g. after a motor was built for car use. Car engines do work fine, but they don't last as long. Using a motor in a marine application is equivalent to running a car at full throttle up steep hills for a long time. They just don't last as long like that. Same problems exist for converting car engines for homebuilt airplane use. It's not done much because they become unreliable after a short time, including all those Volkswagon engines that people have used in airplanes. I guess what it comes down to is what kind of a good deal you got on your automotive engine versus the price of the marine engine, and whether or not the ongoing replacement costs and what not work out to your advantage or not. If you don't hotrod your boat but instead drive it more reasonably and spend long hours fishing or cruising more slowly, then your automotive engine may last just fine. Rule Number One: Change the oil like you change your socks, and use top quality brands
(Castrol) or synthetics (anybody's.) Buy a new crankshaft and put it, along with new main bearings, into the motor before first installation, then follow Rule Number One.

Brian

From: Ron Eike

A year or so ago one of the boat magazines (it may have been WoodenBoat) ran an article on marinizing a Suburu diesel. Maybe you could get some help here.

Ron

From: Steve

One of the major problems of putting a car engine in a boat is the need for water cooled exhaust manifold and the clutch/reverse gear. First, a large part of the heat generated is going to go through the exhaust manifold. You need to build a water jacketed manifold. I've tried insulating them but it doesn't last long. Second, the clutch and transmition from a car are totally in appropriate for marine manuevering. The reverse is geared way to low to be usefull. A automatic doesn't solve that problem and also needs a cooler since there isn't any air flow around it. Also you need a thrust bearing which a car transmitions doesn't have. The prop shaft will be pushing against the output shaft on the transmition and will distroy the ball bearing in the final dive.

My experience and opinion, FWIW.

Steve s/v Good Intentions

From: Craig M

Ok, here goes. First let me say I am a marine mechanic and I only use webtv for the newsgroups. It`s easier and I can`t get a virus. You can use a car engine in a boat, but it won`t last long. Pay attention now, there will be a quiz later. A marine engine has a stainless head gasket. Raw water will rust yours out. Marine engines have different cams, they perform from idle up, a car starts making power around 2 grand. A boat has different pistons, they have more silicone as not to expand as much due to long periods at high rpms. Electronics are sealed cause the spark factor. Exhaust is water cooled so you don`t burn up your boat. Now, think of this: A boat is on 80% load 90% of the time, a car is on
20% load 90% of the time. A car will never run wide open all day, yet a boat will. It`s all cause of the above. Of yeah, if you still use the escort engine, don`t let the coast guard inspect your boat. You will get busted cause of the solenoid not being marine also the started and alternator.

Jeff
06-10-2002, 08:23 AM
The book you referred to was Marine Conversions by Nigel Warren ISBN # 0229116787 or ISBN # 0229117708 (1982)?

Maybe someone else will jump in and have some better links for you as well.

06-10-2002, 10:37 AM
Thanks for all the info. Am I to take it from this, that most people think it is a bad idea to use a marinized auto engine and just raise the extra cash for a purpose built marine motor?

Portager
06-10-2002, 11:09 AM
That depends on two things.

How far are you going off shore and how far can you swim?

If the first exceeds the second, then spend the money on an engine you can rely on.

Just my 2¢

Regards;
Mike Schooley

Jeff
06-11-2002, 07:20 AM
I wouldn't go quite that far... then again, I'm thinking of a twin installation so even if one fails you can limp home on the other ;)

I bought an old Wellcraft with twin 351's 9 years ago because it was all I could afford at the time - I've used it mostly for island hopping and short day trips - the longest about 50 miles, and for that the converted automotive engines are ok. The first month I had the boat, I did end up with a cracked engine block due to a very small amount of water which found its way into the carburator somehow (no shield over the carb itself - just a Holley flame arrestor and the engine hatch) and that was quite a frustration. I also went through a waterpump and when I had to replace a starter (three times!) I wished it was in a better location (which it would have been if it was a marine engine rather than on the very bottom where you could only feel your way around rather than actually being able to see it.

Just depends on your budget, use, skill, and how reliable you require it to be. Mercruisers are also based on automotive blocks - so if you are a skilled mechanic, it's not an impossible task to create a good marine engine. But if you go far enough to be as good, I'm not sure what the cost difference would be (negative or positive.) As Mike says, if I had been going further offshore or if my budget at the time would have allowed, I would go for the real deal if at all possible.

Portager
06-11-2002, 11:29 AM
In retrospect I think my response sounds a little harsh.

My interest is long range "Passagemaker" boats which are almost always single engine diesels. Auto conversion engines don't make sense in this application.

OTOH as Jeff pointed out, they are fine for twin engine coastal cruising applications. Now that I think about it, maybe that is why so many gas powered boats have twins and so many diesel powered boats are singles.

Personally, I think one high reliability engine would be lower cost and much less maintenance than two low cost, low reliability engines, but to each his own.;)

Cheers;
Mike Schooley

07-28-2002, 02:09 PM
Originally posted by Jeff
And some other on-topic posts from rec.boats.building over the past year:

From: John

It can be done since Merc, OCM and Volvo do it all the time. Remember to:
1. Change to Brass freeze plugs
2. Change the Alternator, Starter and Distributor to their respective Marine Versions
3. Change the Air Filter to a USCG Flash suppression type.

From: Bryon Kass

Also add change camshaft, circulator pump, head gaskets, thermostat, carb, intake and exhaust manifolds, bell housing, flywheel, and anything else I forgot. Bryon Kass webmaster and Custom Design
150 Mechanic St. Foxboro, MA 02035
508-543-9068 or fax 508-543-5127, Foot yard 508-384-2415 in THE ENGINE ROOM http://getit.at/engineroom

From: Stephen G. Lusardi

Justin, I'm not sure of you're engine knowledge or skills, but be advised that this task can only be done by very knowledgeable, experienced people or you will have lots of trouble. The following points must be observed.
1) A car engine is a LIMITED duty engine and a marine engine is a continuous duty engine.
2) There are many differences in the following: a. Ignition advance curve b. Valve timing (camshaft) c. Oiling system d. Cooling system. e. Exhaust system f. Carburetor g. Air cleaner h. Alternator I. Starter Please remember when it breaks, you cannot call AAA for service. You become a burden on others, give boating a bad name and risk lives unnecessarily. Please be responsible and do this correctly. Steve

From: Augusto Queiroga Valentim If you do you will regret it........sooner or latter! Probably rather soon. Boats demand a lot of power, and automobile engines are not engineered for continuous full power duty, as marine engines are.

From: Vacuo

It is always assumed that the auto engine installed in a boat is going to be operated at WOT ( wide open throttle) since this fits the behavior pattern of most boaters. But there is no reason why an oversized engine cannot be installed instead, say 2 or three times the displacement. Thus the auto engine can loaf along at 2500 rpm which is near the peak of its torque curve, and thus enjoy maximum fuel efficiency. With the right choices the available power at this rpm will be just what the boater requires.

Thus, a Rabbit diesel is the equivalent of a 20 to 25 hp marine engine- no more. Fine for propelling a sailboat or other displacement hull.

Vacuo

From: Marcus G Bell

Right. When an auto engine is marinized, it's peak HP rating is derated by a fraction. Also, many boaters "cruise" at less than WOT.

The auto engine uses something like 25% of its rated HP to keep the car moving at steady highway speeds. The marine engine very often is cruised at 50-75% of its rated power, which corresponds to something like 33-50% of the peak power of the "same" engine rated for land use.

So a marine engine works harder than a car engine, but it is more steady work than experienced by the auto engine upon which momentary high loads are placed.

-- -- Marcus.

From: John

Marcus Iam trying to figure this out, What is the exact difference between a Marine engine and an auto engine of the same displacement by the same manufacturer other than the obvious (Freeze Plugs, Starter, Distributor ect.) Lets take the Chevy 305 V8 which is used by Merc and Volvo. What are the other difference? If I had to guess I would say the cam is different maybe the heads but what else? In addition I believe that the blocks used are base on truck blocks rather than car blocks.

From: Stephen G. Lusardi

Marcus, There are many differences between a limited duty engine and a continuous duty one. As an example , it is necessary to understand the difference between an SAE work test and a standard BRAKE test. Both tests are performed on the same device called an engine brake or engine dynamometer. Essentially the engine is run up against a variable load. This load device is mounted in bearings so it can rotate, but it is prevented from rotating by a lever which is attached to a scale. This scale will read out in ft. lbs.. So at any engine speed the maximum torque can be read. Because torque is one component of horsepower and speed being the other, horsepower can be calculated as well as fuel consumption, brake mean effective pressure and a number of other items. The important thing is the test program. A BRAKE test is where the engine is warmed to normal operating temperatures and then run up to maximum power and that's the end of the test. An SAE test, on the other hand is run up against the load for a sustained period (maybe 4 hours) until the maximum power is reached that DOES NOT exceed acceptable manufacturers operating parameters like oil, water, exhaust and head temperatures and pressures. In your example you mentioned the Chev. 305. This engine will brake somewhere around 220 to 280 HP depending on state of tune. The maximum SAE rating of this engine is 55 HP.

I suggest that if you were flying on a plane, or on an ocean cruise ship, you would want the engines tested under an SAE test program. The differences in design and build are many. Intelligently, you have to factor the type of usage you need from the engine and then modify the automotive engine accordingly. The greater the durability, the greater the cost. Nothing is for free and when a marinized automotive engine costs are comparable to the standard automotive variety, you must question it's durability. Steve

From: bro

i have a 1972 buick 455 that i plan to put in a 18 ft flat bottom v-drive so far i have chnaged the freeze plugs to brass and i am changing all bearings and gaskets but what should i do on the camshaft ??? thanks jon

From: Stephen G. Lusardi

Jon, The Camshaft should be the least of your concerns. If you intend to to be able to run this engine at more than 1/2 throttle for any length of time, your biggest problem is cooling. Automotive engines do not cool evenly when under heavy load. If you check the water flow diagram for your engine you will see that cool water enters the engine in front by the pump, proceeding rearward gaining heat eventually exiting the block through the steam riser holes into each head between each cylinder. Then the water runs forward within the head exiting to the intake manifold, then the thermostat housing and then back to the radiator. The net effect is that the front cylinders get more cool water than the rear. The two center cylinders have less surface area for cooling as well, so run hotter than the ends of each bank. Continuous duty engines and long track NASCAR engines are modified so that there is a water distribution log mounted on each bank in the lifter valley, under the manifold in an attempt to even the cooling a bit. They run forged crankshafts, cored con rods for spray oil cooling of the bottom of the pistons and many other refinements that have little value when running in a limited mode, but have extensive value when running in a continuous mode. They have high temp. resistant stainless steel valves, stellite valve seats, better guides and oil seals. They use low cam lobe acceleration rates, wider valve centers typically 112 degrees as opposed to performance cams at 106, lighter valve springs to save effort and stress on the valve train. They use thermostatically controlled oil coolers, larger volume oil pumps, larger oil filters that are also incidentally full flow and the list goes on. If you are going run in circles on a lake, carry a set of oars and have little regard for repair costs, I guess these changes are of little value to you. If however your needs are a bit more stringent, please consider a proper marine engine.

From: SAIL LOCO

<<<<<<<The Camshaft should be the least of your concerns. If you intend to to be able to run this engine at more than 1/2 throttle for any length of time, your biggest problem is cooling. Automotive engines do not cool evenly when under heavy load. If you check the water flow diagram for your engine you will see that cool water enters the engine in front by the pump, proceeding rearward gaining heat eventually exiting the block through the steam riser holes into each head between each cylinder. Then the water runs forward within the head exiting to the intake manifold, then the thermostat housing and then back to the radiator. etc. etc.>>>>>>>

I have never seen any engine where the water flows to the heads last. Water always goes to the heads first since that is the hottest part of the engine. The water in every engine enters at the water inlet on the intake manifold and imediately enters the heads water passages.

From: Marcus G Bell

Many, if not most auto engines have the water leaving the bottom of the radiator and entering the pump first. The pump then delivers the coolant to the bottom of the block. Half of the pump volute is often cast integral with the block, and the main pump outlet is then a passageway cast directly into the block's water jacket. A small hose delivers some flow to the intake manifold and the manifold drains into the head, but the bulk flow to the head comes upwards from the block. The thermostat is in the top of the head and the hot fluid leaves the engine through the thermostat.

The flow of coolant through the engine and radiator follows the direction of natural convection. Hot fluid comes into the top of the radiator where it cools and falls, then flows into the bottom of the engine where it heats and rises. The pump assists the convection. It is the rare consumer-grade automobile engine which operates in opposition to this convection, and I know of none of the top of my head. So, I find the statements "Water always goes to the heads first" and "water in every engine enters ... the intake manifold" to be misleading and/or incomplete.

-- -- Marcus.

From: KPB314159

I don't know where this thread started, but I can tell you I have seen many converted auto engines spread out on a dock, waiting for delivery of some replacement frammitz. Most of the problems that could be categorized fell into the cooling area: cracked manifolds, cracked heads, carbon and other problems from running too cold, etc. One common problem is that if things are misadjusted it is possible to shoot very cold lakewater or seawater directly to a hot engine which would never be expected by the designers of an automotive engine. Ken Bowen

From: Wallace Waggoner

Original thread revolved around the differences auto vis marine engines. Does anyone really believe GM has a seperate dision building differnent components for its 5.7 sold to Volvo and Mercruiser? Of course not. You can purchase a parts list for any Ford or Chevy based Marine engine from your local car/truck dealer. Check it out for yourself and see if you can justify the price charged for your boat engine. Marine manufactures have a sweetheart deal with Ford/Chevy. You and I can not go to a dealer and purchase one of their marine longblocks for $2200. You must purchase in the quantity of Redline et al and be a "certified" OEM marine engine builder.

The Marine Industry has been pulling the wool long enough. In the are Its even worse regarding diesel and outboards.

Wally

From: Wallace Waggoner

Outside water-cooled exhaust and the optional FWC Volvo and Mercruiser by a GM engine changed very little from the new engine you purchase from a dealer to put in your car.

Talk to any performance engine builder in your area. He has catalogs for any parts you need for a long block put to marine use. Stellite seats will cost you abbout $8 and stainless valves another $8 a piece. Another $20 for better grade of Clevite bearings.

A marine engine needs low end torgue. You get this by NOT spending huge quantities on high performance heads and trick cams. Standard reliable parts and machining are key. Obviously a few more dollars in incresed cost of Coast guard approved and mandated parts.

Wally

From: krulik

This is all well and good but what are the differences in the construction of the engine. Using that Chevy 305 again, Now, If I change the rear end gear from a 3:23 to a 4:11 that will increase the amount the engine will have to work to maintain the same speed what other changes are needed to the engine? If marine engines can sustain more revs with a greater load they should be used in auto racing? Seems that this would be the next logical step.

From: plkruse@iu.net

I've found this thread to be especially interesting, especially the parts of it that deal with the power ratings of the engines. I'm much more familiar with diesel engines than with gasoline ones, (such that I can quote the spec's of some of the more common ones without having to look them up). So, the examples that I will site pertain directly to diesel engines, but the exact same principles apply to gasoline engines. In fact, I?ll use the CAT 3208 as an example, since it is a V-8 diesel very similar to a large gasoline engine. (636 cid)

The harder you run an engine, the faster you will wear it out. It really is as simple as that. Every engine therefore has many different power ratings, depending upon how hard you plan to run it and how long you want it to last. If I were to tell CAT that I was going to put the engine into a small commercial fishing trawler that was going to run 3500 hours pre year, for example; then they would tell me that the 3208 was good for 150 hp. They would derate the engine so that I could not get more than that much power out of it. If you were then to ask them for an engine for a high performance recreational boat that was not going to be used more than 300 hours per year, then they would tell you that the same engine was good for
435 hp.

What?s the difference between these two identical engines, that they would have such a different rated power? Chiefly this: In both cases CAT wants for the engine to last at least as long as the warranty. Since I?m going to put a whole lot more hours onto my hypothetical boat than you are, they will derate mine in order to achieve that objective. In another example, I was once going to put a CAT 3412 into an air boat. My customer wanted the most power for the weight and the cost, but was happy with an engine life of at least 1800 hours. This is a very unique case, in which CAT was willing to rate the engine at 1000 hp. On the other hand, a friend of mine maintains a fleet of work boats with this same engine in them. He runs them at about 500 hp and gets 50,000 hours between overhauls.

CAT has five different power ratings published for each engine. (If you present them with a special case, you will learn that they actually have more ratings than that.) These ratings go from "A" for continuous duty to "E" for highly intermittent duty. In this example, the A rating for a 3208 is 150 hp; whereas the E rating is 435 hp. Gasoline engines have a similar ratings system, except that the DIN and ISO standards for "automotive power" ratings will give you a slightly higher number than most "highly intermittent" ratings. In other words, it is the peak power you might use if you were passing uphill. It is certainly not the amount of power that you can expect the engine to put out for any significant period of time.

We are currently building two boats, both commercial fishing work boats; and are about to buy an engine for one of them. It will most likely be a Cummins B5.9 in one of its many versions. This is the same engine Ford used to offer in their pickup trucks, and Dodge currently offers. Cummins is telling me that they will rate it for
150 hp in our boat, but it is rated at 220-250 in its various automotive applications, and it is offered in a 300 hp version for recreational marine uses that do not exceed 300 hours per year. To put this into perspective, a pickup truck running flat and level at 75 mph without a trailer will require about 50 hp. The same truck with perhaps a 10,000 lb. gross load would require most of the 220 hp. The same engine in a 25 foot sport fishing boat would probably cruise at about 200-230 hp.

There is a difference between the way commercial truck engines and car engines are rated. (A pickup truck is a car for the purposes of this discussion.) In the case of a diesel truck engine, they are rated pretty much at the power they are operated at. In a gasoline car engine, however; they are rated much higher than you would ordinarily ever use them. I know of another example that illustrates that point nicely. They are two almost identical 35 foot sport fishing boats that typically run over a 100 miles off shore together, where they troll for deep water fish. One has twin Cummins 6B5.9 engines salvaged out of pickup trucks and converted to marine use. The other has twin 454?s, also salvaged out of automotive service and converted. All four of these engine are rated at 250 hp, or within five percent of it. These boats normally stick close together all weekend, until it is time to run home; at which time the diesel boat will beat the gasoline boat home by about six hours. The difference is that Cummins recommends that the diesel boat back off of maximum rpm by only 200; whereas no one is going to run a gasoline engine that hard for that long. That captain backs off about a thousand from maximum rpm. To exceed that speed for long periods of time causes cooling problems. This is very consistent with the way the engines were designed to operated during their first lives as automotive engines.

To sum it all up, an automotive engine will typically run at 20-40 percent of its rated power. (In this case, I?m using "automotive power ratings.") It will only exceed these limits under highly unusual circumstances. If you put the same engine into a recreational boat, it will typically run at 60-80 percent of its rated power. A commercial diesel truck engine typically runs at about 60 percent of its rated power. (Flat, level, 75 mph, maximum legal gross load.) That same diesel engine installed into a recreational boat will often run at up to 95 percent of its rated load, with bursts perhaps as high as 105 percent. If these same engines are installed into commercial work boats, then their service lives would be more similar to the truck or the car. It is all a matter of how long you expect to run your engine before replacing it or overhauling it.

All the numbers I quoted in this article are from my memory. If I were at work, where I have all my reference books, I would have checked them more carefully. They should be fairly accurate, and are certainly good enough for the comparison purposes for which they were intended. Since the same engine is sold in so many different versions, you would certainly want to check the OEM specifications on your particular engine before making any critical decisions based upon these numbers.

From: Rick Morel The above really says it all. I'm more familiar with auto engines used in aircraft, but this is very much like marine use. Except it's a lot easier to drop the hook and look for a tow than start looking for a possible landing site! Know what the prop on an airplane is for? To keep the pilot cool -- turn it off and watch him sweat!

Aircraft engines are much derated for reliability. The old Continental
65HP was used in racers at about 120HP, for a life of a couple hundred hours instead of a couple thousand.

VW engines have been used a lot. In the car, they're rated at about
60HP for the 1,600cc. In planes, if they're derated to 40-45HP, they seem to last forever. If used at 60HP a few hundred hours. Then there are the "high HP" conversions, claiming 85 and more. The life of these seem to be in minutes!

My brother used to build dragsters years ago. He'd get 1,800HP out of Chevy 454.... for three drags. About 30 seconds.

I think someone mentioned a Subaru engine in this thread. The
4-cylinder and 6 have been used on gyroplanes with good results. I forget the spec HP rating for the 4, but used at about 50HP makes for a very reliable and long-lived engine.

To maybe put things in some perpective, the VW is rated at 5,200 RPM, if I recall right, but is set up in aircraft for 3,800 RPM take-off and about 3,600 RPM cruise. The Subaru 4 has I think the same spec RPM, but is used at 4,000 and 3,800.

One more question I remember was how much HP does an average sedan take for 60 MPH? Now, getting to my EV (Electric Vehicle) period. My Electric Ford Escort Wagon took 12.5 HP for 55 MPH. A Ford Ranger pick-up requires 19.2 HP for 55 MPH. Less than we would think. The big difference in HP required (and gas/electron milage) is due almost all to aerodynamics.

Rick

From: plkruse@iu.net

[much good aviation comparisons snipped]

A good way to approximate the amount an engine puts out under any given set of circumstances is fuel consumption. Figure a diesel engine burns about one gallon per hour per 20 hp. The number for a gasoline engine is about 15. These numbers can vary quite a lot for certain applications, but they are good general numbers.

By them, my Honda Civic requires about 22 hp @ 60 mph, and 34 hp @ 75 mph. My dad's F250 (3/4 ton Ford pick up truck), requires 60 hp @ 60 mph when running empty; and 104 hp at the same speed when fully loaded with his 30 foot RV trailer.

I know a heavy recreational passagemaker-trawler (49 ft) that requires
60 hp at 7.5 knots. By the same reckoning, a 25 foot sport fishing boat running at full speed with the same engine requires 300 hp. I've got the same engine, a CAT 3208, in a piece of heavy equipment at work, and it averages about 175 hp. Message 36 in thread From: Mike Goodwin (panmanii@pinn.net) Subject: Re: car engine conversion Newsgroups: rec.boats.building View this article only Date: 1999/05/26


I take it that this is done with the governor on a diesel to limit RPM's , how is it done in a gas engine?

From: plkruse@iu.net

Actually, that is not how it is normally done in a diesel engine. Rather, you will likely find different injection pumps, different injectors, and different computer settings in different engines of the same type that are rated at different power levels. Most often, you will find two engines rated at different power levels to actually run at the same rpm shaft speed, but sometimes the higher rated engine will run a little faster. In some such cases, the moving parts will be better balanced in the faster turning engine; and may even be made of a lighter alloy; but in most cases nothing is done inside of the engine when they are rated at higher shaft speeds.

Another way that is often used for both gas and diesel engines is to control how they are used. A particular boat may be geared and proped such that it can only put a 200 hp load onto an engine at 2800 rpm, for example; whereas the same boat owned by someone else could be geared and proped to place 300 hp on the same engine.

As for how to "dump down" a gasoline engine, I guess that the carburetor or the fuel injector would be the easiest place to do so without putting a higher parasitic load onto the engine. If the engine is computer controlled, then that may also be used, just like with some diesel engines.

From: plkruse@iu.net

They were fairly standard conversions; basically the same thing that you would have had if you where to buy the marine version of either one of these engines. They both had wet marine exhaust manifolds and heat exchangers fresh water cooling. The gasoline engines had the "fire proof" marine carburetor, distributor, alternator, and starter; as well as a flame arrestor on the carburetor. I don't know what cams they might have had in them; and I'm pretty sure that the heads and pistons were original.

If you have a high interest in this, then I'd suggest picking up a copy of "Inboard Motor Installation," by Glen L. Witt and Ken Hankinson. It is available through Glen-L Marine Designs, 9152 Rosecrans, Bellflower, CA 90706. The ISBN is 0-939070-01-4. They cover the subject in good detail that is easy to understand. This includes not only the engine itself; but also every aspect of how to install both it and the transmission.

From: Credence Vision Systems LLC

Truly 'marinizing' motors starts on the design table. The differences go right through the whole engine: Large (sometimes roller type) main bearings on the crank shaft between every 2 connecting rods, different stroke on the motor (more torque at lower rpms), different compression ratio (lower), different cam, different carburetor etc. They take the same basic motor as what is produced for a car, beef up the bearings and make small adjustments to bring the horsepower and torque curves a little lower on the rpm curves. Externally, there are tons of differences intended to make the motor fit in a tight compartment, sometimes use a generator instead of an alternator, and the cooling system is redesigned around the new motor. Go to a boat show and look at the 'Vortec' Chevy engines designed for marine use. Nothing like the 'Vortec' Chevy engines that go in cars, except maybe the block/heads/valve covers and the like are the same.

I'm not sure what 'marinizing' would mean after the fact on a motor, e.g. after a motor was built for car use. Car engines do work fine, but they don't last as long. Using a motor in a marine application is equivalent to running a car at full throttle up steep hills for a long time. They just don't last as long like that. Same problems exist for converting car engines for homebuilt airplane use. It's not done much because they become unreliable after a short time, including all those Volkswagon engines that people have used in airplanes. I guess what it comes down to is what kind of a good deal you got on your automotive engine versus the price of the marine engine, and whether or not the ongoing replacement costs and what not work out to your advantage or not. If you don't hotrod your boat but instead drive it more reasonably and spend long hours fishing or cruising more slowly, then your automotive engine may last just fine. Rule Number One: Change the oil like you change your socks, and use top quality brands
(Castrol) or synthetics (anybody's.) Buy a new crankshaft and put it, along with new main bearings, into the motor before first installation, then follow Rule Number One.

Brian

From: Ron Eike

A year or so ago one of the boat magazines (it may have been WoodenBoat) ran an article on marinizing a Suburu diesel. Maybe you could get some help here.

Ron

From: Steve

One of the major problems of putting a car engine in a boat is the need for water cooled exhaust manifold and the clutch/reverse gear. First, a large part of the heat generated is going to go through the exhaust manifold. You need to build a water jacketed manifold. I've tried insulating them but it doesn't last long. Second, the clutch and transmition from a car are totally in appropriate for marine manuevering. The reverse is geared way to low to be usefull. A automatic doesn't solve that problem and also needs a cooler since there isn't any air flow around it. Also you need a thrust bearing which a car transmitions doesn't have. The prop shaft will be pushing against the output shaft on the transmition and will distroy the ball bearing in the final dive.

My experience and opinion, FWIW.

Steve s/v Good Intentions

From: Craig M

Ok, here goes. First let me say I am a marine mechanic and I only use webtv for the newsgroups. It`s easier and I can`t get a virus. You can use a car engine in a boat, but it won`t last long. Pay attention now, there will be a quiz later. A marine engine has a stainless head gasket. Raw water will rust yours out. Marine engines have different cams, they perform from idle up, a car starts making power around 2 grand. A boat has different pistons, they have more silicone as not to expand as much due to long periods at high rpms. Electronics are sealed cause the spark factor. Exhaust is water cooled so you don`t burn up your boat. Now, think of this: A boat is on 80% load 90% of the time, a car is on
20% load 90% of the time. A car will never run wide open all day, yet a boat will. It`s all cause of the above. Of yeah, if you still use the escort engine, don`t let the coast guard inspect your boat. You will get busted cause of the solenoid not being marine also the started and alternator.

10-08-2002, 01:20 PM
There exists a book on the marinisation of engines.
This book is not available. But some libraries have it, and there you can copy the relevant passages.
In Germany the Library of the University of Hamburg has it.

gonzo
10-29-2002, 12:07 PM
Marine blocks have a high chromium content for corrosion protection. The crankshaft is hardened. Also the camshaft is different from an automotive because the load and rpm usage are different.

Guest
09-28-2003, 02:09 PM
Who can supply Stainless Steel Heat Exchangers to fit a GMC 6.2L
Diesel V8

gonzo
09-28-2003, 02:34 PM
Heat exchangers are made of bronze or monel. Stainless steel will corrode. What configuration of heat exchanger do you need? It is necessary to know shape, size, hose connection positions and bracket type.

Gypsy72
03-26-2004, 10:44 PM
regardless of gas or diesel, one thing you can not forget is ventilation,
ventilation, ventaltion.
the ambient air temp in the engine room must not get too high.
this will cause loss of power and possibly engine damage.
as for gas installs, fumes of course is the issue.
make sure that your natural ventilation does the job completely on its own.
blowers are there for other reasons.
the engine manufacturers will have the numbers your looking for concerning this matter.
Also be concerned,when converting automotive to marine (gas or diesel), with coolers and there placement in the system.
having a oil cooler or a fuel cooler in the wrong sequence could produce temp problems.
all in all, converting is more hassel then its worth when your talking gas. marine engines are plentiful and affordabale.

GizmoStang
05-17-2004, 04:04 PM
I look of good points here for the electronics...

But a few issues about the use of Automotive Engines... Mercruiser and OMC both utilitzed late 70's early 80's GM Small Blocks that are if anything weaker than installed and any GM Truck.

They had the same factory Teflon coated Timing Set that was a major downfall to GM Automotive engine for years.

With the Price Merc wants to charge for "Std Marine" engine components you can purchase Race Quality parts ran out at the max redline you will ever dream of running a boat engine at for a fraction the cost and have a much more solid engine then Merc or OMC ever made, especially since neither ever even bothered to use a 4 bolt main block to strengthen the bottom end of their motor.

Sorry but if an SBC can handle 10,000 - 12,000 rpms tasked of it in drag cars or long distance circle track driving it will be more than enough to run 4500 - 5000 rpms in a boat all day long. Anything over that range you put your lower unit in serious risk of anyways. By the Way Pre-OD Tranny Cars & trucks cruise indefinately @ 4500 rpm's for well over 100,000 miles...

Use Graphite Race Head Gaskets, High Quality (Clevite or Michigan) Bearings, find a good Comp or Crane Marine Cam and put it together and have no worries of the engine being the cause of your problems

Use the Marine Water Pump, Brass Freeze plugs... You can even pickup up used Marine starter/Alternator on Ebay and fully rebuild for 1/2 the cost of new ones, 90% are Delco Products and can be rebuilt with standard Automotive Brushes, Bearings and such which will still retain the flame protection and run like new.

Personnally I'd go with a stock GM Hei distributor and simply substitute the advance weight springs, its a much more reliable system and will never fail.

Boris Vukusic
05-29-2004, 05:37 PM
Hi, I have 28ft sport cruising boat Sidra 28 GTO with 2 OMC 5,0 L (ford 302) V8 engines and Cobra stern drives. Now I want to replace engines with 2 GM 6,2 diesel Chevy V8 and I need help. If someone have information what and where to order for marinisation. Please help me, I am in Croatia-Europe and have no experience with GM engines. Mail me on bimex@zg.htnet.hr

gonzo
05-29-2004, 07:22 PM
It is an incorrect comparison between a race car and a planing boat. Cars do not run at maximum torque load like a boat. This produces higher combustion chamber pressure and temperature. Also, the load curve to put a boat up on plane is different from the one to accelerate a car. Graphite race head gaskets will create violent galvanic corrosion that will shorten the life of the engine and drive.

grob
05-29-2004, 08:06 PM
Try Lancing Marine in the UK

http://www.lancingmarine.com

Misogynist
05-30-2004, 02:37 AM
In one way... marine engines are remarkably like car engines.... they share lots of parts... If you were to check a lot of "high performance" offshore engines.. you will find that most of them use aftermarket Generation IV Chev blocks 9.8 inches from centerline of the crank to deck height... or 10.2 ( tall block)... Most of these are either Chevorlet "bow tie" blocks... or from an aftermarket manufacturer like Dart or World Industries, ( Merlin )... Most of the time the water pump is removed and a "sea pump" with a rubber impellar is installed.Sometimes the factory water pump is left in place for circulation. But whether you are using a "closed" cooling system with a heat exchanger.... or an "open" cooling system that uses the raw water from what the boat is floating on...you must have a "sea strainer". Some of the internal problems incurred because of the high load factor of a boat application is oil cooling...plus, because of the constant higher combustion chamber temps.. it is advised that inconel exhaust valves be used... especially if you are planning on supercharging the engine, and Stainless intake valves. There are plenty of manufacturers of water cooled exhaust manifolds. Some people prefer the nice shiny stainless tubular versions.. some like the cast versions. The biggest problem I've seen with raw water cooled offshore engines is they run too cool... if you are running is salt water.. you don't want the temps any higher than 150. If you are running a heat exchanger.. then you can run more normal temps like 180 degrees. My understanding is hot salt water can be very corrosive. Much more than cool salt water. I ran raw water cooling on my boat... and it is understood that the blocks and heads were disolving and would eventually need to be replaced. Besides the brass core plugs.. you should install zinc sacrificial anodes in the water system... If you really aren't familiar with marine engines.. you are just building yourself a lot of problems. I've seen so called "experts" cobble together some real disasters.Even Mercruiser has had problems with their propulsion units... they have been mating big 502 cubic inch engines to whimpy Bravo outdrives with cone clutches.. If you were to go to offshore boating forums... you would see how many people are moaning about toasted bravo drives.. So... even the people that are building marine power plants for public consumption are having fits. So... even a properly "marinized" automobile engine isn't without it's problems. I think most people with high performance auto engines that have been converted only expect about 300 to 500 hrs before they are worn out and need serious attention. It has been theorized that a new expensive offshore boat can cost upwards of $2,000.00 dollars an HOUR to operate... Especially at today's fuel costs... My boat had twin 540 cu in Blown Chev engines and when "cruising" at 60 mph... they consumed about 80 gallons per hour... and when you really started working the "sticks" it would go over 100 gallons per hour... but... at 100 mph on the ocean... you couldn't run that fast for long... you would get too tired hanging on.... :)

Boris Vukusic
06-01-2004, 04:53 PM
In one way... marine engines are remarkably like car engines.... they share lots of parts... If you were to check a lot of "high performance" offshore engines.. you will find that most of them use aftermarket Generation IV Chev blocks 9.8 inches from centerline of the crank to deck height... or 10.2 ( tall block)... Most of these are either Chevorlet "bow tie" blocks... or from an aftermarket manufacturer like Dart or World Industries, ( Merlin )... Most of the time the water pump is removed and a "sea pump" with a rubber impellar is installed.Sometimes the factory water pump is left in place for circulation. But whether you are using a "closed" cooling system with a heat exchanger.... or an "open" cooling system that uses the raw water from what the boat is floating on...you must have a "sea strainer". Some of the internal problems incurred because of the high load factor of a boat application is oil cooling...plus, because of the constant higher combustion chamber temps.. it is advised that inconel exhaust valves be used... especially if you are planning on supercharging the engine, and Stainless intake valves. There are plenty of manufacturers of water cooled exhaust manifolds. Some people prefer the nice shiny stainless tubular versions.. some like the cast versions. The biggest problem I've seen with raw water cooled offshore engines is they run too cool... if you are running is salt water.. you don't want the temps any higher than 150. If you are running a heat exchanger.. then you can run more normal temps like 180 degrees. My understanding is hot salt water can be very corrosive. Much more than cool salt water. I ran raw water cooling on my boat... and it is understood that the blocks and heads were disolving and would eventually need to be replaced. Besides the brass core plugs.. you should install zinc sacrificial anodes in the water system... If you really aren't familiar with marine engines.. you are just building yourself a lot of problems. I've seen so called "experts" cobble together some real disasters.Even Mercruiser has had problems with their propulsion units... they have been mating big 502 cubic inch engines to whimpy Bravo outdrives with cone clutches.. If you were to go to offshore boating forums... you would see how many people are moaning about toasted bravo drives.. So... even the people that are building marine power plants for public consumption are having fits. So... even a properly "marinized" automobile engine isn't without it's problems. I think most people with high performance auto engines that have been converted only expect about 300 to 500 hrs before they are worn out and need serious attention. It has been theorized that a new expensive offshore boat can cost upwards of $2,000.00 dollars an HOUR to operate... Especially at today's fuel costs... My boat had twin 540 cu in Blown Chev engines and when "cruising" at 60 mph... they consumed about 80 gallons per hour... and when you really started working the "sticks" it would go over 100 gallons per hour... but... at 100 mph on the ocean... you couldn't run that fast for long... you would get too tired hanging on.... :)
maybe it is the best vay for me to buy original marine diesel engines! There is so many informations against marinisation of Chevy 6,2 engines. Also may be problem with rotation- one engine left and secon right rotate becouse of OMC Cobra stern drive.
Thank you for your ansver
Boris :confused:

Boris Vukusic
06-01-2004, 04:54 PM
[QUOTE=Misogynist]In one way...
maybe it is the best vay for me to buy original marine diesel engines! There is so many informations against marinisation of Chevy 6,2 engines. Also may be problem with rotation- one engine left and secon right rotate becouse of OMC Cobra stern drive.
Thank you for your ansver
Boris :confused:

Boris Vukusic
06-01-2004, 05:52 PM
Try Lancing Marine in the UK

http://www.lancingmarine.com
thank you very much :)

Gregg
06-09-2004, 03:36 PM
I have a similiar question; I just blewout the head gasket in my 1989 Mastercraft Tristar. This is a competition ski boat with a Inmar Ford 351 Windsor engine. Pulled off the heads and found they were corroded thru to the water jacket; my case is probably so corroded that it needs to be replaced. Did I mention the previous owner had the boat in salt water for 7 years before I bought it????

I am planning on purchasing a reman marine long block and stripping mine down to the core. The 'new' engine will cost me $1,600 plus all the other assorted parts and gaskets I will need. I could get a 351 short block from a local salvage dealer and remanufactured heads, replace the freeze plugs with brass and put my old carb, exhaust, starter, etc on it alot cheaper. I also have to change the cam out due to the marine engine is LH turn. Is there anything else I need to change? This post talked about alot of things such as pistons, etc. that are different. I just need to know what parts are different inside the engine.

Misogynist
06-09-2004, 05:41 PM
I have a similiar question; I just blewout the head gasket in my 1989 Mastercraft Tristar. This is a competition ski boat with a Inmar Ford 351 Windsor engine. Pulled off the heads and found they were corroded thru to the water jacket; my case is probably so corroded that it needs to be replaced. Did I mention the previous owner had the boat in salt water for 7 years before I bought it????

I am planning on purchasing a reman marine long block and stripping mine down to the core. The 'new' engine will cost me $1,600 plus all the other assorted parts and gaskets I will need. I could get a 351 short block from a local salvage dealer and remanufactured heads, replace the freeze plugs with brass and put my old carb, exhaust, starter, etc on it alot cheaper. I also have to change the cam out due to the marine engine is LH turn. Is there anything else I need to change? This post talked about alot of things such as pistons, etc. that are different. I just need to know what parts are different inside the engine.
How hard do you plan on running your boat? If it is a ski boat... probably not as hard as an offshore high speed boat. I'd suggest since the boat already has a marinized Windsor.. just get a used block and heads... take them to a reputable engine rebuilder. Play mix and match with the "marine" parts from your old engine such as the cam, since it is reverse rotation.. the rest is a lot more simple than starting over with a clean sheet of paper.. you already have the marine reverse starter and charging system. The big difference in the internals might be better pistons and oiling system... When an engine runs under a constant load... the pistons and valves run hotter... so don't skimp on good pistons and valves. I'm sure you can get some aftermarket forged pistons and better quality valves...I know J and E forged pistons are about $1,000 for a set of 8 . I'd go with the inconel exhaust and stainless intake valves for longevity. Go with a "high flow" oil pump to ensure good oiling of the internals... People think that high pressure means high flow... not always... some marine engine builders like to have bearings on the "loose" side of tolerances so that more oil splashes up on the cylinder walls to aid upper cylinder lubrication. ( Since the engine rarely gets the high manifold vacuum during deceleration like an auto engine ) there is less oil sucked up past the rings and onto the upper cylinder walls. Run a good quality 10-40 oil ( not straight weight ) because you want the flow past the bearings as much as oil on the bearings themselves. This is one of the biggest problems I find boat owners do is run too thick of an oil and starve the upper cylinder areas of lubrication.I'm sure you already know about brass core plugs in the block and "marine" head gaskets.

woody
06-10-2004, 01:56 PM
I have been using auto engines in boats for years.Forget all the mumbo jumbo,this is how I do it.This may sound crude to the people who preach new stuff but here goes.I usually try to find a rusty pickup or car with V8 that runs good(it is easy here on the coast),use model before computers.Then remove engine ,change freeze plugs,get your water cooled exhaust manifolds.Install engine and hook up raw water cooling and go.I use the same distributor that was in vehicle.changing carb and fuel pump is up to you ,I never do.Also a 2bbl carb will work fine.
I have been putting engines in boats I built for 24 years just like I described.Don`t worry about salt water and raw water cooling,rusting out the block is an old wives tale,my engines have always been in salt water with no problems.
I am sure this post will get a lot of flack,but the joke is on them,because this works and is inexpensive.

yipster
06-10-2004, 02:35 PM
http://www.sh-boomm.com.au/images/flame%20shirt.JPG
it is easy
couldnt get my head to fit the shirt :D

gonzo
06-10-2004, 03:41 PM
Woody: an automotive distributor is not spark protected. You have been lucky not to have an explosion. The moving parts of a marinized engine are different from an automotive. You may be running a low performance boat. In a planing hull the low end torque requirements are higher than for a car. If you don't change the camshaft the boat will be a pig. Also, blocks in salt water rust. It is a proven fact. If you use automotive head gaskets with steel inserts they will rust through first. You also don't change the carburator, starter or alternator. It may be cheaper but also foolish and illegal.

Misogynist
06-10-2004, 04:28 PM
Dang Woody.... sounds like the way to go.... until the hull burns to the water line because of a leaking fuel pump and a little spark from the starter or alternator or distributor.... It's not anything that you could sell to someone.
I don't think there is a single manufacturer of an auto engine later than 1980 that doesn't have a computer of some sort on the engine management. 1983 was the last year for a car or light truck with a carb.. So... you must be putting in some old stuff....

eurotk1
06-10-2004, 09:13 PM
If The Engine Is Pre 79 Advance The Cam Timing 2deg With A 3 Position Timing Chain Set.after 79 The Cams Were Retarted To Meet Nox Limits For Emissions.so In A Engine After 79 Advance The Cam 4 Deg.any More Than This Can Cause Valve Clearance Problems.retard The Ign Timing Total To No More Than 38 Deg If Comp Ratio Is Below 9.5 To One.also Do Not Use Vac Advance.the Water Pump Needs To Be Underdriven Or The Bearings Will Wear Premature.if A Marine Water Pump Is Avail Use This Instead Because It Has Bigger Bearings And A Stainless Impeller.a Flame Arrester Must Be Used And The Carb Vents In The Case O A Holley Must Be Modified To Prevent Fuel Spillage During Bouncing.a Marine Starter And Alt Are A Must.the Difference With Fuel Pumps Is That If The Diaphram Leaks A Line Sends The Fuel To The Intake Instead Of The Bilge.good Luck Hope I Was Of Some Use.i Have Converted Vw Diesels Mercedes Diesels Ford Gas And Chevy Engines With No Problems.these Are Guidelines For Cruisers Not Peformance Hulls.

tom kane
07-01-2004, 11:24 PM
There are advantages to auto engines in boats.

tom kane
07-02-2004, 12:00 AM
There are advantages to auto engines in boats.
Availability of latest auto engine technology and parts.New and secondhand.
Local servicing and familar products.Use new v8 bow tie blocks or seasoned 60,s engines with heavy castings.Check casting and serial numbers from manafacturer data bases for information about blocks containing forged cranks heavy walls ect.Custom design and choice for basic or sophisticated units.You have choice of all auto or marine camshafts and charging and ignition systems.A variety of power units small and large and you can fit Turbos, Superchargers.Auto motors are used in light trucks and utes and are geared for that job,so use the same principle for your boat.
Choose type of carburetted or EFI petrol or gas fuel systems as gas could be half the fuel costs so twice the fun.Fit remote fuel systems for safty.Use auto soft engine mounting with crash safety fittings for quiet vibration free running.Environment friendly gas or petrol motors fitted with insulated dry exhaust to burn cleanly,catalystic exhaust scrubbers.
Use auto cooling systems,enclosed reliable and remotely fitted radiators,electric fans,heaters plus heat exchangers to suppliment cooling for motor.Fit motors in closet drained and ventilated overboard to discharge any exhaust or fuel residue overboard and preferably installed at the rear of the boat.Fit fuel cells and explosion proof fuel tanks in seperate closets drained and ventilate overboard with fuel lines and filling points outside of hull.
These are some possible points for discussion.tom kane.

gonzo
07-03-2004, 12:30 AM
I don't know how it is where you live. Here, marine engines are fuel injected and have the latest technology in electronics. If you were to use an automotive fuel injected, computer controled engine, the changes would be beyond your capabilities. For example, how do you reprogram the computer to account for a marine engine not having an oxigen sensor. It cost more to marinize an automotive engine than starting with a marine one.

tom kane
07-04-2004, 05:51 AM
I don't know how it is where you live. Here, marine engines are fuel injected and have the latest technology in electronics. If you were to use an automotive fuel injected, computer controled engine, the changes would be beyond your capabilities. For example, how do you reprogram the computer to account for a marine engine not having an oxigen sensor. It cost more to marinize an automotive engine than starting with a marine one.
Hi Gonzo.Auto trade apprentices here are changing motors from car to car just for fun and installing new and second hand imported replacement motors for crash repairs and replacement ect.These motors need to be computer tuned and modified for good performance,just as they would,and can do on imported marine engines.this work is part and parcel of modern engine work where ever they exist.De- sophistication of a modern engine for more reliable marine use can make sense for some people.So-called sophisticated technology is being manufactured in most poor countries of the world and is easy copy as pirate business of the world shows.There are many very clever and educated people in all countries,poor and rich,all over the world.
Thank you for your comment.tom kane.

gonzo
07-05-2004, 05:30 PM
Marine engines are not "de-sophisticated". Try working on an 8.1 without a computer or proper training.

tom kane
07-06-2004, 12:58 AM
Hi gonzo,modern tech seems no problem to a lot of lads today where ever it is.
Vehicle Emmission control Information
This vehicle is fitted with computer Engine management System,which controls Fuel Mixture,idle speed and Ignition timing.Adjustments for these functions are not provided. you must recognize this tag.

This sign may say that nothing can be done-but that just ain,t so.there is everythig that can be done from re-writing the chip,fooling the computer,or using a fully programmable aftermarket computer.there are many aftermarket Programmable Engine Management Systems on the market that are not expensive and can cope with many motor configerations,gas,petrol,diesel,twostroke,tom kane

Danielsan
07-06-2004, 08:19 AM
Hi there,

I'm kind of new on this site, but have seen many interesting things.

Somebody can help me to I hope, even if it's just a hint,...
(Brief intro)
I 've allways been dreaming about having a boat but those things are really expensive? So some time ago I started calculating the possible cost of all the separate equipements. And begun the design of a 7.42meter x 3.2meter small planning cabin/flydeck cruiser. I started with the motor and thought a BMW 2.4TD 120HP engine in 2nd hand in good shape cost apr. 700EUR - 840USD. Knowing I have to do some things about cooling and so on. The first thing would be having a fresh water cooling and an extra oil-cooler this schould cool things down whitout having the oxidation probs. as with the open water cooling. Right?
The endurance: I mostly drive my cars (2nd hand BMW) 160.000miles avg speed 50 Mph this means 3200 operating hours. A big deal of that time on the highway I drive 107 Mph 4500RPM.
Could I say that if I get an output ratio 2:1 or 3:1 and I reduce my RPM max to 3000RPM (even less) I would get an output of 6000 - 9000 RPM? theor. Would that be a problem?

Kindly yours,
Danielsan

gonzo
07-06-2004, 10:32 PM
Marine gears are usually a reduction ratio. If the propeller turns too fast it will cavitate. A boat plows throught the water. Try towing 1500 kg uphill with your car at full throttle for a couple of hours and see if it survives it.

Ilan Voyager
07-07-2004, 03:09 AM
This thread about car engine marinisation shows mainly two schools of thinking:
-The american
-the rest of world

The american school uses highly modified big V6 or V8 mainly with raw water cooling. This is a consequence of the traditional american engine car used since more than 70 years. As these car engines were made to be very cheap, they use 1940 technical solutions that make these engines unable to work hardly during a long time and are generally undercooled (I know by experience: I had american cars here in Mexico).
So for marine use these engines have to be modified, sometimes very heavily because the technical option of salt water cooling obliges the engine to run too cool. At more than 50 Celsius the salt deposits and cloggs the water passages. Exhaust must be water cooled, or the head will crack.
The corrosion problems are a big problem in these engines as I see everyday on the Mercruisers and Volvos , specially in the short lived exhausts which can ruin the whole engine by leaking inside.

The european and asiatics ( I include Australia and New Zealand on the asiatic side) having a different background use other solutions:

- diesel (in Europe the use of a gas engine is unthinkable with gas at more than one dollar a liter). By nature the european automotive diesel are tougher that gas engines and can be used directly on a boat without internal mods.
Also european use always fresh water (in fact doped ethyglicol) with intercoolers: nobody in Europe will use a highly corrosive liquid (salt water) as coolant inside a small engine. The engines are used at the temperature for what it has been designed.
The english Ford (Ford had always a special line of engines for the european market), Mercedes, Iveco and many other european diesel engines can be used on boats without any problem of reliability. There are a lot of conversion kits like Lancel in England. The japanese diesel are generally very good also.

- gas for small engines. The european and japanese automotive engine are truly tough, and they are used WOT with no problems (ask a german who has no speed limit on highways and who runs 600 km WOT in less than 4 hours with a 2.0L Zetec engine...) and can go on a small boat simply with heat exchangers and a marine gear box (and the usual security modifications).

You see that in the evolution of automotive engines of american cars, the big boys Ford and GM are using now foreign modern designed engines. A matter of survival in front of the japanese.
For example Ford uses on the Focus and the Ranger a Duratec 2.3L L4 DOHC Four Valves all aluminium. When you see the origin of this engine you understand the evolution of the last 30 years of the american market. The basis of the design and foundry technic is Cosworth (english) and "redesigned" for big serial fabrication by Mazda (japanese). The engine design is straightfoward and cheap to make.

The engine on the Ranger gives 145 HP with a naked weight of about 120 kg, but gives with the same internal parts 185 HP without problems of reliability. And with little preparation 240 HP are obtained, the engine will last one complete rally races season ( a hard job of wide open throttle with overrevvings) without rebuilding.
That means that for the Ranger the engine has been DETUNED. You see immediately that this engine has a great potential for marine use, without any internal modification, but with the common sense security modifications. You find this engine brand new for 2295 US$ in the Ford Racing catalog and other sources are far cheaper. I shall add that the original iron exhaust collector may be used with a insulation if some precautions are used at the joint with the classic marine escape system. A lot of marine engines are used with dry escapes in warships and fishing boats.

Lets compare with a 130 HP so called GM marine engine: the 3.0L L4 pushrods and 2 valves. The engine has been designed beginning of the sixties for the Vega car and shows its age. At 130 HP is giving far more that it can, being OVERTUNED.
Besides it's a kleenex engine, pratically impossible to rebuild.
In industrial applications big problems appear at more than 80 HP (the true HP that the design allows), and the LP gas burns the valves in a few hours.
My personal opinion about this engine when used in light commercial duty is that it's a piece of junk you have to throw every 1000 hours if it has not broken before, generally by blowing the head joint.
For the peace of this thread I won't give my opinion about the Mercuiser and Volvo stern drive transmissions.

Australians use commonly car engines with the original gearbox; as I know by my australian friends the lone problem is the design as the automotive gear boxes are very long. The australians make also automotive EFI that can be tuned and do not have any problem with electronics.

The american technical way is nor the better, nor the lone that can be used. Each technical way has its pros and cons. But I have to remark that the american design of the american 6 and 8 cylinders, big, heavy and thirsty is now obsolete.

Danielsan
07-07-2004, 04:46 AM
Thx,
I got a bit disapointed by the previous threads. Now I didn't know there was such a big diff between US and rest of the World car engines. That's why the most of you have a negative opinion for that kind of operations.

Ilan Voyager somewhat confirmed my idea THX, but I still have to do some more "research".

What concerns the RPM I only intended to say that I could reduce Motor RPM to get a convienient RPM and multiply it to get a reasonable output RPM. So it's even better that I don't have to multiply to much so I can keep some of my Hp in the low RPM zone of my BMW (car)engine.

THX,

Danielsan

tom kane
07-07-2004, 10:23 PM
More info for Gonzo.Oxygen sensor.To keep down emissions and give a low fuel consumption,the Engine Management System computer often checks on its own mixtures,using an Oxygen Sensor in the exhaust,this probe constantly measures the oxygen content of exhaust gasses-allowing the computer to work out air/fuel ratuio at any instant.if you cannot find an Oxygen Sensor in the exhaust close to the motor you probably do not have a modern full Engine Management System.tom kane.

gonzo
07-07-2004, 11:40 PM
Ilan:
I said 8.1, they are all fresh water(antifreeze) cooled from the factory. I also rebuild, and make pretty good money, 4.3 all the time. They can take three rebuilds, hardly a "Kleenex" engine. The part of the exahust that corrodes faster is the riser which lasts about 3 years in salt water if you don't flush the engine.
Tom kane:
What marine engine is using oxigen sensors? All the prototypes I've seen and worked on have problems. There are no sensors in the market that can differenciate accurately between steam and exhaust gases.
There isn't such a difference between US and other designs. Putting all US engines together makes no sense. They range from high revving four cylinder to 8 cylinder engines with high low end torque.

Corpus Skipper
07-08-2004, 01:30 AM
Woah!!!! Put on the brakes there compadre! I have to take issue with several of your comments.[
QUOTE]This is a consequence of the traditional american engine car used since more than 70 years.[/QUOTE]
There's a reason for that. They're reliable as hell. I have a 1980 Chevrolet 1/2 ton pickup with the original engine. It's been rebuilt twice, the last time being just a ring and bearing job. It's a 350 with 4 bolt mains. She pulls boats around all the time. I have two of these same engines in my 26' Chris Craft. They're fresh water cooled and run terrific. Sure, they burn gas, but they push 10,000 lbs of boat along at a 20 kt cruise at 3200 RPM. Should be less, but she's underpropped. Try that with a jap 4-banger. Besides, I sure don't want all that aluminum (anode?!!!) in my sea going boat!!! Gimme iron! specially in the short lived exhausts
Sure, Merc and Volvo manifolds don't hold up, but my Crusader manifolds were 10 years old when I changed them out, and I was pleasantly surprised to see plenty of meat left in them. My new Osco manifolds (Crusader replacements) are very hefty, and I look foreward to 10 more years out of them.
these engines unable to work hardly during a long time and are generally undercooled
I don't know what you're talking about here. My truck, pulling a 4000 lb. boat at highway speeds (60+) in the South Texas summer heat today (96 degrees, heat index of 106) ran right at 185 degrees, 5 above the thermostat. This is a 25 year old truck! My boat is the same, with seawater temps at 85, she runs at 175 with 170 thermostats and never wavers. These engines are 1979 models, overhauled last year. They were last overhauled in 1993. 10 years on a boat engine ain't bad!
The engine has been designed beginning of the sixties for the Vega car
Hate to bust your bubble, but Vegas weren't around in the 60's, and the 4 banger Vegas were Cosworth.
The american technical way is nor the better, nor the lone that can be used. Each technical way has its pros and cons. But I have to remark that the american design of the american 6 and 8 cylinders, big, heavy and thirsty is now obsolete.
You're absolutely right, each has it's pros and cons. Big 6 and 8 cylinders are required to push along a big heavy boat at a decent rate of speed. They are not obsolete, they're in their prime. The 8.1 Gonzo mentioned is a stump puller, and very efficient for the power produced. Sure, we'd all love to have a diesel for the ultimate in power and economy, but the fact is, I can buy TWO brand new Crusader 5.7s WITH GEARS for the same price as ONE diesel BOB TAIL!!!!! That buys an awful lot of gas with the money I have left over, and the maintenance is 1/3 the price of diesel. And as for European or Jap 4 bangers, they just don't have the stones to push a boat the size of mine at any decent rate of speed.
For the peace of this thread I won't give my opinion about the Mercuiser and Volvo stern drive transmissions.
These things are aluminum (anode, right?) They're not made to be left in the water 24/7, much as they'd like to say so. But if trailered or kept on a lift, they're just fine. There are tens of thousands of them running around, and they provide good service when maintained properly (Bravo IIIs have major corrosion problems, but not mechanical). And since yours was an American rant, Volvo is European (Swedish?), not American. Maybe you've dealt with some crap, everyone has theirs. I can't count the number of people I know who have to replace their Toyota 22R heads left and right (if you can find and afford one). Mitsubishis in the pickups are notorious for busted exhaust manifolds. I could go on. But I'm done. :D

tom kane
07-12-2004, 01:03 AM
Steam in any exhaust system would not be good Gonzo,=corrosion every where.There could be a message to marine designers here. There must be somthing better.tom kane.

Dalton O Adams
07-16-2004, 09:17 AM
I am interested in Marinizing 2 Nissan TD-42 Diesel Engines which I would like to fit in a Boat,

gonzo
07-17-2004, 12:55 AM
Tom Kane:
You claimed there are marine engines that use electronic management including oxigen sensors. Which one were you referring to? Steam in the exhaust is a reality of marine engines. Designers take it into consideration. It is why marine exhaust systems are different than automotive.

tom kane
07-18-2004, 11:14 PM
hi Gonzo.No suggestion was made that marine engines used oxygen sensors,they are used to advantage in auto systems along with the latest Electronic Engine Management Systems.In the latest 2004 Product Bulletin that I have on the 8.1/DP -IGX
systems are explained well such as EVC/MC-Plug and go(option) which is claimed are based on the latest automotive technology,plus the extensive range of accessories.As a choice for myself dry exhaust insulated and water jacketed where appropriate gives the reliability of a motor car.tom kane

Robbi
07-19-2004, 01:35 PM
Hi!

Interesting discussion you have here.

Here on the west coast in Finland they constantly marinize auto engines. Mostly the engines are diesels because of the very expensive gasoline.

Take a look at

http://www.netti.fi/~seppniem/introduction.html

Regards,

Robbi

Danielsan
07-20-2004, 01:07 PM
I agree with Tom Kane, However changed the engine in a 325-525TDS engine got some more HP. I Think I will isolate exhaust manifold and wrap some stainless steel tubular construction between fiberglass isolation tissue and exhaust cooled by some fresh water. I think it will exchange enough heat to cool things down. The rest of the electonics an sensors will remain same as in the car. total cost around 2.000 USD, it's higher than estimated before because the use of an more recent engine with low milage. Now I still need to figure out drive and steering somebody has an idea. Thinking about some surface drive thing with conventional steering and maybe some trimming device?

Greetz

Danielsan

Suede
07-23-2004, 02:49 PM
Hi,
The reason for wrapping your exhaust with insulation is to keep the gas as hot as possible on it´s way to the Turbo, if you cool it down the gas volume will be less and it will lower the effect of the turbo (oppsite to an intercooler where you want more gas into the engine). Maybe you can use a external water cooled "oil-cooler-type of element" to take care of the heat radiated from the exhaust and cool down your engine room.
You might also convert your alternator to external diods. It´s a lot more power needed to charge empty battries on a boat, and diods will heat up you alternator much more than it was designed for.
So your cooling issue starts after the gas exit the turbo...
You will find products and ideas if you search the net for the guy´s building extreme turbo cars and diy-aircrafts....
rgds
Olle

gonzo
07-23-2004, 05:09 PM
What are you doing about the electrics and fuel system. Automotive electrics are not spark protected. Automotive fuel systems use a return line. Both are illegal and dangerous in a marine installation.

Suede
07-23-2004, 06:53 PM
Most marine-alternators are modified auto-industy units, it´s still an open unit for air-cooling...so it will most likely produce as much sparks as in a car. Better cooling, wireing and bearings seems to be the main mods, sometimes isolating terminals for external regulators, not using engine ground.
I don´t se why car electrics should produce more sparks....being stuck in a traffic-jam might then be expose you to high risk for cars going up in smoke...or.... :D
overall I think a lot of boat manufactors have a long way to go before the reach the installationstandards of the car industry.....

Illegal or not, but why should it be more danger to run two fuel lines instead of one....if it´s ok to have two or more main tanks and one day tank....fuel lines i between and more pumps....
But your right....doing this type of installation is not acceptable for a boat yard or professional shop, it´s a d.i.y-project....and you must be aware of the risk....but still interesting..

rgds
Olle

Corpus Skipper
07-23-2004, 08:45 PM
Most marine-alternators are modified auto-industy units, it´s still an open unit for air-cooling...so it will most likely produce as much sparks as in a car. Better cooling, wireing and bearings seems to be the main mods, sometimes isolating terminals for external regulators, not using engine ground.
They also have flame screens over the air holes.

gonzo
07-25-2004, 12:00 AM
Marine alternators have screens to make them spark proof, just like and old miner's lantern. Automotive fuel systems have a return fuel line that works in conjunction with a pressurized fuel tank and a fume return tank. Return lines are dangerous and illegal in marine applications. Marine fuel systems have only one feed line and a fuel/vapor separator. I think it is irresponsible to promote something that endagers other people's lives. An exploding boat can do a lot of damage.

tom kane
07-25-2004, 12:18 AM
If you build your boat so that there is no chance of any fuel vapours occuring within
the hull of your boat you should not need all of the patch-up methods now applied to a supposedly legal boat systems.Just because there are laws on this matter does not mean there is no better way to do the job, in a safe and good engineering approach.
Why should we not be entitled to the best safety approach for our boats?tom kane.

tom kane
07-25-2004, 12:24 AM
If you build your boat so that there is no chance of any fuel vapours occuring within
the hull of your boat you should not need all of the patch-up methods now applied to a supposedly legal boat systems.Just because there are laws on this matter does not mean there is no better way to do the job, in a safe and good engineering approach.
Why should we not be entitled to the best safety approach for our boats?tom kane.

gonzo
07-25-2004, 05:27 PM
Tom Kane:
The rules have a basis on research and technology. If you know of anything better, please share it with us. Seems like your post are always criticizing existing standards. However, you never offer any better solution. There is no "patches" in marine engines. It is a different system. I think your comments are based on ignorance and arrogance. Also, they may encourage people to use installations that are dangerous and illegal. Are you willing to commit yourself in writing for a different method? I put all my warranties in a contract form which makes me liable.

Danielsan
07-26-2004, 07:40 AM
Hi guys,
Hope you won't get into a fight outhere? :-)) I agree there is a diff. between marine and automotive apps. But there is also a commercial issue. Why is it that even the most ordinary pieces (f.e. rudder) cost a 4 fold of designing one myself and getting it done by a machining company and with all respect, the thing I've on paper does like more robust than the one I can buy off the shelve. Is it design cost (I don't count that fo myself) or is it just a commercial issue. Concerning the Car engine I still think there is no probl with it. The only thing I would change is the alternator, because the need of more power, so the thing I will do is getting myself a marine one. As it's a diesel engine there should be nothing more to change (stater engine). A good forced ventilation and I think it wil get safe down there.
There is another thing to know, I think the legislation in Europe and the States is some more diff. Because f.e. feul return lines are allowed in our boats, the fill-up systems come along with that inlet.

Greetz,

Danielsan

tom kane
07-26-2004, 06:39 PM
If you have not already read the Thread,Safe Remote Fuel System for boats,Gonzo,in Open Discussion,along with the description and the image of the same name in the tom kane photo gallery,it may be of interest.It is open for constructive critisism.the double posts were not intended,the Edit Option was not available.Patch-up in my English-American Dictionary means..to bring(a quarrel,dispute,etc)to an end.thanks tom kane.

PAR
07-27-2004, 12:12 AM
Tom Kane . . . "If you build your boat so that there is no chance of any fuel vapors occurring within
the hull of your boat you should not need all of the patch-up methods now applied to a supposedly legal boat systems."

Clearly, some talk out their butt's and others pass the regulations and requirements as routine for a living. Maybe down in the other half of the world, it's not necessary to keep from blowing yourself or friend to hell in a hand basket, but in the real world (yes, you MUST compare to the USA regs) you have to muster at least an attempt to stabilize the results of your actions, if not be responsible for them out right.

I've just settled this with a side bet on another forum. I called GM and asked about the marine engines they build for many (damn near all) the boat engine builders. The question was, "What's the difference with the engines you supply to marine applications, compared to the stuff you bolt into automotive applications."

The list of parts was quite long and very different from the stuff you get from the engine bay of a Buick. The USCG regulations aside, the motors produced by GM (the industry leader) were much more robust, to keep it short. Forged parts through out the application. Cast pistons for the most part (high output not included), but little else was the same. Not even a good automotive short block, from the same manufacture would muster up.

Mercruiser buys their engines from GM, who builds them to spec. The engines show up on their doorstep with bullet proof parts (race breeding) and accept the bolt on stuff from other suppliers and still carry a GM warranty! Why? They build a 400 HP engine and stick a 220 HP (to Mercruiser's specs of course) cam in it . . .

Tom Kane's idea of "fuel vapors occurring . . ." is an old idea and has been well juiced by performance users for many decades. Placing the air intake outside of the "box" for a fresh air charge (the real reason for such changes) will allow you to forgo vent loops and shaft seals in the carb (anyone still using one is going to lose the race) but this does not negate the needs of spark/flame/vapor proofing and other, related improvements to fuel delivery. This is dependant on the seal being below the base of the carb. Most don't do this and take their chances, also negating any added benefits of the denser air charge, as the vents, and breather holes must be of the same pressure, or the increased air charge is worthless.

This is the country of standard. This is where most boats are sold. The USA is where most boats are raced. This is the place where you must account for yourself. This IS the place where you CAN account for yourself. WE repeatedly come up with new ways, ideas and standards to compete with. Those that can't keep up, usually just bitch . . .

Danielsan
07-27-2004, 10:55 AM
PAR,
are you one of the others that pass the regulations and requirements as routine for a living or do you also have some constructive ideas for someone who thinks pricing a boat for 150.000USD/3ft (in Eurpope) is way to much?
We don't want to innovate, we just want to have another approach on the things. Can you tell me why a car engine wouldn't use flame proof equipement. If there are none then we just change them. What fumes does a Diesel engine produce in the motor compartment besides the oil vapour outlet that comes back into the air inlet? A spark free alternator and starter can be found off the shelve. What's more?

I think this is a forum so people can help other people find solutions or making up ideas, good or bad.

Just a last thing: You guys make the most boats, engines, standards,etc,....
But also the most fake weapons of mass destruction reports!

Just know the Space Shuttle has a heatshield made of 32.000 little ceramic tiles none of the 32.000 has exactly the same shape, so the crew can't take some spare parts just in case there would be one ore more lost in space... They got fried!!! Nice standards
or was it just a commercial issue?

Hope not offending you people over there on the other half of the world

Daniel Peeters

Corpus Skipper
07-27-2004, 02:40 PM
Just a last thing: You guys make the most boats, engines, standards,etc,....
Let's not turn this into a political argument, I think most of us come here to get away from that crap.
Just know the Space Shuttle has a heatshield made of 32.000 little ceramic tiles none of the 32.000 has exactly the same shape, so the crew can't take some spare parts just in case there would be one ore more lost in space... They got fried!!! Nice standards
You got a better design? Let's have it. Those shuttles have been flying for almost 25 years, and to have had only 2 accidents in all that time speaks volumes. But like I said, let's not turn this into political arguments. I hate politics. :D

yipster
07-27-2004, 03:31 PM
"When anyone asks me how I can best describe my experience in nearly forty years at sea, I merely say, uneventful. Of course there have been winter gales, and storms and fog and the like. But in all my experience, I have never been in any accident ... of any sort worth speaking about. I have seen but one vessel in distress in all my years at sea. I never saw a wreck and never have been wrecked nor was I ever in any predicament that threatened to end in disaster of any sort."

Edward J. Smith, 1907
Captain, RMS Titanic
(struck iceberg and went to the bottom just five years later)
from http://www.commanderbob.com/


http://www.commanderbob.com/acc_stat1.jpg
was just readin uscg about fires and quote above when the e-mail bell went. just to set some things straight: i'm all for recycling, inovativity etc but a car engine ventilates its explosive fumes away under the body, a boat is a bowl that holds them in. and there is much more different. diesel is in normal condition not explosive as mentioned earlyer in this thread but make no mistake, it can burn very hot and furiously also. boating is expensive i agree but do realise most of that price is there with very good reason!

btw the spaceshutle can and has been entering earths atmosphere without some of those fantastic tiles, it is designed that way.

TheFisher
07-27-2004, 09:36 PM
It is not immune from explosion. Having been trained as a diesel mechanic and specifically as a diesel fuel injection technician I can say that diesel fuel can, and will, explode via a spark. Given a high pressure leak that emits a fog of atomised fuel and vapor, a decent spark will ignite the fuel and cause it to burn if not explode.

Try an experiment with it sometime if you doubt the above.

As Yipsters chart show, fuel fires/explosion cause the most damage. 160 incidents and over $11 million in damages.

We all have choices in life. I choose not to put myself, my family, my crew, or my guests in danger unnecessarily. I don't want to have to be towed back to port from 30 or miles out due to an engine, fuel, cooling, electrical, or other failure. The standards are there for a reason. They have been developed and proven over time.

I prefer safety over an award.

Please don't advocate that others apply for a nomination for the Darwin award.

Danielsan
07-28-2004, 08:07 AM
Hi there, did I step one someone's toes?

Didn't mean to. :cool:

I do sometimes agree with you guys, but not always :)

I wanted to post but it got lost, so I'll try to remember what I wrote.

Still persuaded that laws are quite different in US and EUR. The returnlines for fuel are permitted, the fuel lines are the same for car and boat use except that the material is sea (water/air) resistant for boat use.
So we change them. Beside the alternator and starter there is nothing that will create sparks in a diesel engine? Correct me if I am wrong. So we change them too. What about gas sensors - alarms? I sure there will be no gas problems if the engine compartment (boat) is vented properly before, during an after operating the engine.

I also hate politics but I had to use them :D The next item I got from an official US site so I don't consider it as politics.

Did you know that the US has the most vehicle fires of the industrialised countries? There is one every 82 secs. It's including aeroplanes, boats and trains. That makes 384.585 fires a year subtract the 160 boat fires it is giving u 384.425 fires not boat related, looks high to me. I do not know what it represents in relation because there are way more cars than boats but cars frie up too!

The reason for those 160 boats/year, is it the weekender or holiday guy that goes on the water and not checking his engine regularly? Is it the fisherman that has to put every penny aside to survive and therefore has to neglect his boat even if getting fried or drowned? Is it the devoted owner / builder that is proud of what he achieved and inspecting every possible malfunction on his vessel?

Excuse me by pushing it till the end but I am a commercial and engineer I'll try to argument as far as possible so I can analyse all the pros and cons.

Greetz,

Daniel Peeters

yipster
07-28-2004, 06:56 PM
do what you please, but do some reading on subjects of your interest please, that never hurted anyone

PAR
07-28-2004, 10:50 PM
Most companies building for the industry, don't want the eye's of big brother looking over his shoulder, or worse regulating his actions. The result is design, engineering and techniques to discourage boneheads from blowing themselves into Davie Jones' locker. Otherwise the government folks will likely write a foolish law with too many loopholes, trying to please too many interested parties, in an effort to appease a pissed off public or answer their outrage (which directly translates into the government types losing their jobs in the next election), in short a law that doesn't really address the real problem, just one that will stop the crying.

Cars by their nature, do not put people in an unnatural environment. This is why the regulations and requirements for them is quite different then boats. If a car has a fuel leak, heaven forbid catch fire, you can stop, get out and call the local firehouse, AAA or your lawyer. A boat is a different beast altogether, where the people are placed in an unnatural environment (farther from shore then they can safely swim back to) Aircraft are quite similar in this regard, but the swimming is done in a much less viscous fluid, and in both environments the resulting drop to the bottom is at least undesirable, if not a bit uncomfortable.

This being the case, (lets stick with boats) the prime concern for the regulators and designers is control of the things that may have catastrophic results. Fire is without a second in battle while at sea. I know, I was faced with a fire and a major leak several years ago. I fought the fire first and dealt with the leak using stop gap measures until I could place more crew to the task of stopping the leak after the fire was contained. Fire is the fear all sailors don't like to think about and the task all navies of the world spend the most time drilling, training and equipping for.

A boat can be vented, but this may require an operator to flip a switch (no good, as there are way to many bone heads in the world, who can't even remember to put the plug in the transom before launching) This leaves the industry and regulators with few options. Diesel doesn't explode unless highly compressed, but it does burn real well and hot. Gas does explode and I've seen too many boats burn to their waterlines over the years to attest to the fools that can afford to operate one.

What are we left with, dumb luck? A responsible society doesn't let it's public hurt themselves without at least trying to slow down the bonehead's ability to paint themselves into a corner. People will always find a way to get themselves hurt or worse, it would be the result of an indifferent society if it was preventable with a few requirements placed on well intending manufactures. I'm one of those manufactures (no more "Z" codes in the HIN on transoms I build! This is a new thing for me and it's way cool!) and I strive to design, produce and refine, update and retro fit the best thinking I and others have, in an effort to provide the best damn boat I can. Possibly, production manufactures must keep costs down and don't pursue the best or safest unless it's mandated. A shame, but competition in this marketplace is tough. I wouldn't be able to sleep at night if I thought I'd shortcut a feature to trim costs, increasing my bottom line and costing someone's kid their arm, leg or life.

Back to the American thing. We repeatedly have proven better, faster, more efficient ways of doing things, in fact it's a trait this country is known for world wide. We do this because we live in a environment (this country and it's principle foundations) that rewards the brave, insightful, daring and calculating individual and shun centralized control, uniform thinking and the choking of ideas and innovation. These are the tenets of our society in this country and it has made us great, powerful and yes full of ourselves at times (sorry) but we also act responsibly towards our brothers here and overseas.

We have more of everything, bad and good in this country, mostly because of the number of things we have, including fires. Gun control laws would help cut down a few of the other things we have way too much of as well. So take the stats with a grain of salt (maybe the whole shaker) as this country has so much more then most, it's not a fair comparison.

Ultimately, you will be the one who has to trust your engineering. If you haven't backed it up with the appropriate education (as I suspect in Danielsan' case) then you could be the next unlucky person to no brain yourself into a hole you can't get out of. I just hope you don't drag someone else kid(s) with you . . .

woodboat
07-29-2004, 02:36 AM
Not to send this good thread down a rabbit hole but this Gun control laws would help cut down a few of the other things we have way too much of as well. So take the stats with a grain of salt (maybe the whole shaker) as this country has so much more then most, it's not a fair comparison. Is very misleading and does not belong here. The current approach to gun control is the removing of guns from Law abiding citizens. One only has to look at statistics to realize that this approach is futile. It is virtually impossible to own a gun in Washington D.C. yet crime is through the roof. When the right to carry becomes easier such as in Virginia and Florida there is an almost instant reduction in violent crime. So if you are trying to talk statistics maybe that was a bad example. Now back to your regularly scheduled program :)

Danielsan
07-29-2004, 05:05 AM
Damn you guys,
some did hurt me to the bottom of my heart. As I saw posts in other forums, PAR can't come up with any good constructive ideas maybe because he is to related to existing things, (It's much more easy to install something you can buy off the shelve) or just to bonehead to follow what he learned in his educational thing. :o

So don't fool yourself to much thinking of being the best, I always liked the states, I still do,(they let me make good money) but some of you are just to "bonehead" to realise there is something else.

Concerning the 'Big brother thing" It's not the government that comes up with the good/bad ideas to write down. It are the developers, commercials, suppliers that do the lobby thing and then the govt people write them down, it is and it will always stay a commercial issue no matter how you want to turn it. I know it is because that's my job. We are an engineering company and we make them write the standards. Worldwide,even in the US!

Maybe some of you convinced me but the price and the quality of a 2nd hand marine engine is not worth it to buy such a thing.

The better thing to say would be "if u don't have the money, don't buy/build a boat", that's the most easy way. I don't like the easy way.


Greetz,

Daniel Peeters

PAR
07-30-2004, 01:14 AM
In 1935, condom tests had a 60% failure rate. This was done during the debate over regulating the industry in congress. In 1937 the industry was regulated, as the industry wouldn't or couldn't self regulate (right) their products and the failure rate fell below 5% before our entry into WWII. This is a classic example of regulation, by a responsible society and carried out by elected officials. I wonder how many people would have blown them selves up if spark arrestors were not required? How many more millions of dollars would go to the bottom if vent loops and throttle shaft seals weren't required?

Asking for good ideas that don't increase an industry's or company's bottom line is like pulling teeth. Industry doesn't supply the lobbying efforts for regulation, unless it's in their best interest (read increased profits) They provide just the opposite of this, a direct challenge to the government trying to get a handle on an issue.

Engineering firms rarely "force" regulation, because the don't routinely cross over into areas not already covered by some regulation or another. Innovations from whatever source usually aren't addressed unless someone wants more tax money, control over distribution or use. This means someone toes got stepped on, or they believe so, and have deep enough pockets to effect a local political power.

Danielsan, I'm not quite sure what you want. Your previous posts are full of "I think it will be okay if . . ." kind of thinking. This isn't the work of an employee at an engineering firm. Research is the hallmark of all engineering.

If one blindly runs through their ideas, they will fail at a rather high rate. Most of the rest of us have to account for near every dollar spent and each spent on speculation would gather much more enlightenment playing poker with their friends or at a craps table, then frivolous attempts at less then well thought out engineered enhancements, to products that seem to work quite well at present.

This isn't to suggest you should head for the barn and go home. I'm just asking you do you homework, your research on the subject(s) you "don't have a problem with" as you posted earlier. Clearly you have a problem with the way things are done now, maybe it's the money thing, who knows, but rejecting it out of hand or without a complete understanding, is the work of an amateur and couldn't ever be taken seriously by any professional.

On the other hand, if you can back up your clams of the unnecessary "stuff" that is regulated or other wise installed or required, you will have a case to make, in fact one that could earn a great deal of money for you. You'll still run into all kinds of flak from the folks who don't want to, gear up for or spend more money on change.

France, Great Britain, Canada and Brazil had less then 800 combined gun deaths in 2000. In the USA several thousand during the same year. Is it that American's as a rule, have much less regard for human life while owning a gun? Or, is it the fact that France, Great Britain, Canada and Brazil have enacted gun control REGULATIONS. There's that word again. To some like Danielsan and woodboat a word that is difficult to live with. It is a necessary evil, someone has to make the call and we've elected them, so they do. Personally I haven't had to use a gun since I left the military and do own several, but the facts are very clear. A household in this country that has a gun is dramatically more likely to be involved in a shooting (imagine that . . .) though this wasn't the point of the post, effective regulation was (a lot less people died by gun shots in regulated countries then non-regulated) although of topic, a note worthy point.

guest
07-30-2004, 04:21 AM
take all the marine stuff off the one that's in it and find a good used one and change it all out on it. Stainless head gaskets, brass freeze plugs, ect. Or buy a new/rebuilt jasper one. Or put a darn transom bracket and a big whompin outboard and deep 6 the I/o. But save the automotive carbs and starters for de cars. The horns on carbs for boats drain in, and a good carb shop can fix a car one up, and most boats burn with a real distinct black smoke anyhows, so you'll probably get someones interest.

Danielsan
07-30-2004, 08:28 AM
Hello there,

PAR, this is the most constructive comment you gave over the past posts. I hope this settles a bit the little quarrel over here.

The reason why I use a lot the words as "if, or,..." I always talk that way. It is the rather diplomatic way, and I don't want to get to arrogant by presuming I am sure.
I am indeed quit sure of my thing otherwise I wouldn't hammer on this thing like I did so far.

I hope this forum can go on with what we were into before our discussion.

So where did we stop! :-)

greetz,

Daniel Peeters

PS To guest, I don't have a boat, I am building it from scratch even design is almost from scratch apart from the hull part that sits into water

woodboat
07-31-2004, 11:45 AM
PAR, I agree with you for the most part on regulation. I know you could build a good marine engine from off the shelf parts. Problem is by the time you do it you would have spent less money simply buying the correct engine in the first place. When it comes to safety issues regulation is good provided it is truly driven by safety and not a political agenda. A good analogy would have been the new burners for gas driven water heaters or as you provided the condom issue. An example of good intentions gone awry is my kitchen faucet. New regulations limit my water flow to something unusable. It takes 13 minutes to fill the sink with water to do dishes all in the name of water conservation. I am on a well and know fully about water conservation. I also agree mostly about the profit statement but... With current news media and lawyers the public opinion often forces their hand way before regulation. The pinto gave the industry such a black eye that they seem to voluntarily recall defects much sooner than regulation would have forced. Regulation being government driven tends to very slow to move. I know in the regulated phone industry the companies wanted to drop their rate but were forced to keep them high by regulators. It is speculated that the lower rate meant reduced taxes so they had a vested interest. Your reference to gun control had no place in this otherwise logical discussion. The problem with disarming law abiding citizens is that you can not regulate human behavior. Since when do criminals obey the law? Why don't we pass a law that everyone must speak nice to each other then there wouldn't be any more fighting? Ridiculous? Of course. Does it go against our first amendment rights? Of course. Don't miss my position. I am all for certain regulation like back ground checks so that criminals do not buy guns legally and strong penalties for straw purchases. When guns are taken from law abiding citizens like happened in D.C. you have many who are simply afraid to go to the city and people with cash hiring body gaurds that can carry. In florida where they are now allowed to carry in the car has greatly reduced car jackings. There is much good information available just do a search. Here is one http://www.fff.org/freedom/fd0210e.asp Anyway my point: Because human behavior is involved the reference had no place when discussing engineering.

PAR
08-05-2004, 04:25 AM
I think for the most part, the people who build engines in boats and have to make money at it, do so in the most reasonable, economical and responsible fashion. This may mean a short block from a vendor with a "accessory" swap out from the dead motor.

Unless you've got a large enough operation to justify the tooling for rebuilding, it doesn't pay. Personally, I get a great deal of enjoyment building an engine to a set of specs I've come up with, in an attempt to meet some performance value. I can only afford to do this on my own projects as the time, money and energy spent couldn't pay for the effort expended.

I agree with most of the regulations imposed by the various governing bodies. I'm seeing a trend for more regulation, that is in my mind an answer by politicians to kick the guy that can do the least amount of harm (pleasure boaters) rather then get into a battle with folks who can tie them up for many years in court, in a case they may well lose.

In coming years we will see some of the things Danielsan would like to try. It's happening now, 2 strokes are going away, digital fuel/engine management controls and the lot. Though I question the logic of putting catalytic converters on lawn mowers, it's coming too. It's in this vain I question the need for such regulation and it boils down to the politicals wanting to say they did something and effecting a "cure" At the same time I'd think requiring the large ship traffic, plying our waterways, to meet much better minimums for deposits, discharges, and other junk into the environment would go farther to cut down or reverse the cycle congress is attempting to address.

So they pick on us. They pick on us, because it's the easiest and shortest path to saying "look we did something . . ." which is all they need to voice to get re-elected. If they really wanted to do something they'd go after the big traffic, but doing battle with them would yield little in the course of their congressional term, so . . .

This is the way of modern society unfortunately, but if I'm to stamp my manufactures code on a transom or expect to be paid when an invoice is delivered, I must comply (I can bitch though) and for the most part, the regs. do help make the experience a safer and better thing.

Yes, a lot of the regs, in fact all that apply have been watered down and run through committee, before they became law, loosing a bit if not most of the teeth intended. This is the way, we have little choice in the matter, so we work around what's there.

Woodboat, you can remove the "restriction orifice" found in your faucet. I have a well also and look for devices that increase flow, not restrict. I have a shower head that will burn the hide right off you, while using 50% less water then a conventional shower head.

We have and just tried again this summer in congress to regulate human behavior. It's against the law to kill, rob, mug, steal, harm, touch, talk about and yes, even think about certain elements of life in this country. 60% of he gun related deaths last year in this country were performed by people using stolen guns. Law abiding folks get their guns ripped off and Joe Blow crack head buys it out of the trunk of a 1972 Nova for $20, then marches down to the local 7-11. If only law enforcement, military, collectors and others whom prove the need (body guards, etc.) are allowed to own a gun, Joe Blow crack head will have to resort to strong arm tactics and maybe get his ass whipped instead. A good fist fight is a hell of a lot better then a good gun fight (I've been in both)

Again this wasn't the point. There is no reason not to believe, that if gun control laws were much tougher in this country, that gun related deaths would drop just as dramatically as did in the other countries around the world. That type of regulation is needed. We can still own the guns, but will have to qualify and quantify for the right to bare them.

woodboat
08-05-2004, 09:14 AM
I can not remove the restriction on my faucet. It has a built in sprayer that pulls out. The head is fed by very small lines. There is no way to increase the lines. If regulations are so great why do you advocate removing the restrictor that was clearly a result of government regulations? You make some grievous errors in your assumptions. You assume that we will all be nice if guns go away, Or that somehow we are all equal and my 70 year old Father would do well in a fist fight. No, quite the opposite. Time and time again a gun has been used to stop crime. Again you speak in theories not reality. In theory communism sounds great. In practice it was horrible in USSR and is pretty bad in China. Again where would you rather live with regards to violent crime? London which has strict gun laws or switzerland http://www.freerepublic.com/forum/a3b7f78c351b6.htm How about washington D.C.??? or lovely Virginia which is only a few minutes away. You live in a dream world like star trek where money is not needed and everyone simply works hard because they want to and everyone is just nice and gets along. I can not continue down this rabbit hole any longer. I am out.

Danielsan
08-05-2004, 09:38 AM
Yo,Yo,YO!

I thought this was a boatdesign forum? What about car engine marinisation?
Some more points of view? I am still into my BMW2.5TDS car engine, might step to a AUDI 2.5TDI V6 one(has more HP),...

Greetz,

Daniel Peeters

woodboat
08-05-2004, 01:27 PM
My position on auto engines in marine applications: marine engines are engineered as continuous duty, auto engines are not. Marine engines also have various changes to address heat from working in a tight compartment as well as resistence to explosion. Differences vary from engine to engine but as an example my inboard has a different oil pan, valve covers, dipstick, intake, exhaust, carburator, fuel pump, block, crank, rods, piston, cam, distributor and alternator just off the top of my head. There isn't an inexpensive way to convert a standard car engine to a marine application. Also in your example the higher horsepower motor in all likely hood will not last as long as the lower model. It will be cheaper to buy a proper marine power plant and in the end it will be far more reliable.

Corpus Skipper
08-05-2004, 11:53 PM
but as an example my inboard has a different oil pan, valve covers, dipstick, intake, exhaust, carburator, fuel pump, block, crank, rods, piston, cam, distributor and alternator
The intake, block, rods, crank, and pistons are all production GM, Ford, Chrysler, or whoever's engine is used. They all use factory high performance pieces which were available in muscle cars or trucks. The Crusaders from my boat were all original as from Crusader, and included a GM 350 4 bolt main block, 992 casting high perf. heads, forged steel crank, and Chevy "pink" rods, all of which were factory production pieces, and all still available from the GM performance parts catalog. Nothing extremely high tech. Cams are cams, with the exception of reverse rotation engines which are a special grind for the backwards firing order, and these engines use a gear drive instead of a timing chain to keep the cam, and thereby the distributor, rotating in the same direction. The new Crusader engines are all GM, right off the assembly line. There simply isn't a large enough demand for full "marine" engines for everything to be porpose built, when factory engines do the job quite well. Crusader bolts on wet manifolds, marine carb (or EFI), starter, alternator, and distributor, extra capacity oil pan, remote oil filter, paints it blue and sends it out the door.

woodboat
08-06-2004, 10:25 AM
To clarify: In my boat those parts are different versus what was standard in a standard car. One could buy the HP parts such as the block with four bolt mains and make a motor suitable for marine use. My engines are old. Currently the HP parts are available in some cars making the GM parts readily available. So a "standard" hp GM motor can be suitable as a base. I have NOT researched the engine but do not think I would try to play with a BMW 2.5 TDS V6.

Danielsan
08-06-2004, 11:22 AM
I am not shure either, at this moment I am searching for the adequate engine. I do find car engines with the HP I would like and with good torque running at 3000-4000RPM, but also found traditional diesel engines DAF, Perkins,... with lots of HP and even more torque at lower RPM 1800-2200 also much heavier, almost twice as much?
Those engines can run up for hours and hours on and on, I don't know where to put them? they are to long.
Not that it matters I still have to build the boat, but I need the extra space as I want to get 4-5 people sleeping on board, with little WC-Shower comp. LOA24.5ft, Beam 8ft, displacement 6200lbs fully loaded with 4 people waterand fuel,...

greetz,

Daniel Peeters

PAR
08-07-2004, 01:36 AM
3,000 to 4,000 RPM sounds like a hunk of American iron to me. Big blocks spin their reciprocating mass even slower and all the metal flying around in a 454 or 572 develops big chunks of torque, which is what we want. Slow turning engines live longer, but generally are heavier.

As kids we use to build "stump puller" engines, basically as long a stroke motor you could do within the block with minor machine work. They spun up slowly, but pulled like crazy. It was difficult to break these motors.

The latest thinking is to use smaller engines to save weight and fuel and spin them up with appropriate gear reduction making the torque. I dislike the idea of a prop spinning the water to a froth and being asked to push a heavy boat. Using light weight parts inside light weight engines is a good way to increase the profitability in a powertrain generating a targeted output range. After the warranty period is over what do they care.

Give me a big wheel and a big, fat, low tech, highly reliable, easy to repair, plentiful parts, American push rod V8 of substantial displacement and the beast will pull hard, long and can be rebuilt when it's time, with over the counter parts. When you rub the rings down on the newer thinking engines, you'll run into interesting difficulties like porousidity in the cylinder walls because there isn't enough meat left. This happens on American V8's as well, but the block usually has been bored a few times and after say 70 to 90 thousands has been cut this will also be the case.

As a general rule, automotive engines can have a much higher HP rating, because it's only required to produce this peak output for very short bursts and amounts to a small percentage of the total time the engine operates. This isn't true with marine applications, where the engine must develop the peak output most of it's life. This is why the 350 CID Crusader engine produces 230 HP, but requires the "pink" (developed for racing) GM rods installed. The same engine built with the same parts would have a warranty from GM in one of their cars with over 400 HP and one could be expected to get 200,000 reasonably trouble free miles from it.

Marine engines are continuous duty, as are aircraft engines, stationary engines for pumps, generators and the like. They run up to their operating RPM, temperature and pressures and stay there, usually under full or near so loading. This is like a car, full of fat guys, pulling a trailer full to it's roof with bricks, up a 45 degree incline, having a driver making a dent in the floor boards with his right foot, it's whole life. The average automotive engine isn't up to the task, at least not for long. It lacks the HD parts, hasn't the necessary cooling, balancing or application specific components to keep from burning itself up.

Yes, you could build one, but the parts would eat you alive, because you'd be getting them without the huge purchasing power of a marine engine builder buying hundreds of assemblies at a time. Parts sales are where the real money is made by car companies and engine manufactures. Retail for them is generally 500% (no kidding . . .)

Suede
08-08-2004, 09:56 PM
Ok PAR...so you belive that the "huge purchasin power of the marine industry" is the reason for the very costeffective marine engines.....sorry I don´t. Ok an aftermarket camshaft is more expensive than stock....but not by 500%...
Maybe your 500% is if you buy everything from a retailer as parts....but normally you start with a second hand engine...a a few parts are already in your toolbox.
On the other hand....if I should build an engine from parts from marine-supplers....500% would be a bargain......

rgds
Olle

gonzo
08-09-2004, 01:23 AM
Pink rods are not different from the stock ones. They are pink because the factory tests them with die for cracks.

Corpus Skipper
08-09-2004, 10:57 AM
Right on Gonzo, that was my point. :D

Danielsan
08-09-2004, 11:16 AM
I am back :cool:

After all I might have listened to you guys :p

I made my choice. It will be a 6Cyl in line PERKINS diesel engine 150HP comming from a crane. RPM 2000 on and on and on,... torque I don't know but I am sure it wil be enough. No electronics, no turbo, just diesel, 24VDC, and fresh water and it turns (not forget OIL). Weighs some 300-400lbs more but that won't make me feel bad.

(Next step would be putting in a diesel V10 6L TDI 536HP engine with CPU made only for operating diesel pump-injection and turbocharger)

So the big block, traditional thing wil get in it first.

Now the next step(s)

Greetz,

Daniel Peeters

tom kane
08-11-2004, 08:45 PM
The future direction of marine engines should be interesting,with the big engine manafacturers committed to aluminium V8 and V6 auto motors.This must become the basis for boat engines in years to come.Alloy motors, Fluid closed cooling,Comprehensive Engine Management Systems even checking on fuel leaks and saftey.Turbo and Tuned intake and exhaust Systems with emission controls.Computer Diagnistic and fault finding.If you have trouble at sea all you would have to do is to contact the engine manufacturers website,and they will be able to sort out the problem while you carry on fishing.The biggest down side would be that you would not be allowed to do the repairs yourself.

gonzo
08-12-2004, 08:27 PM
One of the greatest improvements has been in lubrication. Modern oils last longer and reduce friction to a much greater extent. An old design engine running on syntetic oil will last at least twice as it did with a 60's oil.

Danielsan
08-13-2004, 04:26 AM
Maybe this isn't the place to ask this but I will start over here.

Does any of you kan tell me what Is the avg. output rpm of a prop during cruising?

Thx in advance,

Daniel Peeters

gonzo
08-13-2004, 07:48 PM
There is not such thing. Every design and installation have different RPM ranges.

Corpus Skipper
08-20-2004, 02:53 PM
Perhaps this will help lay some debate to rest. As seen at www.ebasicpower.com. I had the actual page link, but my @#%$!! computer wants to freeze up. Guess it's time to give it another lobotomy. :D

woodboat
08-21-2004, 12:38 AM
What is the picture supposed to prove? Is the picture of a 2 bolt main Chevy small block mean we can all rush out and marinize our V6 ford out of a Taurus with good results? American V8s are some of the most durable gas engines available. So what. I have used an engine out of a nova in a boat. That doesn't mean I would recommend something just because I did it and lived. Heck, who's engine is that so I can never buy one?

Corpus Skipper
08-21-2004, 10:03 AM
Heck, who's engine is that so I can never buy one?
It's a Mercruiser "factory replacement block". Sorry, I would have elaborated more yesterday but my computer is giving me fits.

woodboat
08-22-2004, 12:33 AM
Is it a "true" photo or just something posted on the web? So is mercruiser now using the weaker two bolt main blocks?

Corpus Skipper
08-22-2004, 10:50 AM
Is it a "true" photo or just something posted on the web?
I'm not sure if it's an actual photo (no way of knowing), but i've rebuilt a few Mercruisers with 2 bolt blocks. I've also seen 2 bolt blocks from PCM, Indmar, Crusader.....

gonzo
08-22-2004, 12:32 PM
It seems like marinizing engines deserves a forum of its own. Perhaps with a boxing ring:) It brings forth more debate than anything else. I am going to start a thread suggesting a separate forum.

woodboat
08-23-2004, 12:32 AM
I can see where a two bolt small block may be OK in say a 19 FT bowrider, relatively light load, never seeing blue water kinda thing. I had one in a 26 FT trojan in semi-protected waters. I don't think I would trust one in my current 50 FT where my small blocks seem under powered. I have to run in excess of 3400 RPM to get in the mid teens.

yellowrosefarm
08-24-2004, 08:17 AM
It seems to me like most of differences in the long block assembly relate to the use of raw water cooling. SS head gaskets and brass freeze plugs being the most obvious. So if you run a heat exchanger where all the engine sees is antifreeze mix, why would you need that stuff. I'm trying to decide which route to go with the 350 in my 19' Renken. I'm strictly a small lake guy where having a breakdown is not the biggest deal in the world. It seems like buying a heat exchanger and setting up fresh water cooling would be a lot cheaper than building and trying to maintain the full marine version. From the number of people in this discussion, I would say that the "marine" motors don't hold up all that well either. It's just a tough environment for any engine.

FAST FRED
08-24-2004, 02:58 PM
"Hold up" is very subjective. A car engine would work fine for the usual 100 hour a year 1000 hour service life usually designed into most outboards.

Car engines suck in big boats where they drink 25gph each and don't last very long running 12 hour days.Used at 5 to 10 gph would make all the difference.

A second water pump will be required to use a heat exchanger cooled car engine .

The heat exchanger should be figgured on cooling the exhaust manifolds too, and after the exchangers (engine & tranny) the sea water is dumped into the exhaust .

The usual seawater pump is a Jabsco , so needs to have impellers renewed every season , 300 hours , or sooner if you run in dirty shallow water.

Marine kits are avilable to do this to a large number of engines.

455 Olds Rocket power?

FAST FRED

Danielsan
08-24-2004, 03:40 PM
Hi back into fight LOL

A part of a post that I did in the beginning, some superflu calculation

The endurance: I mostly drive my cars (2nd hand BMW) 160.000miles avg speed 50 Mph this means 3200 operating hours. A big deal of that time (if not all the time) on the highway I drive 107 Mph 4500RPM.

Even I would say avg RPM during Holliday trip
4000-4500 during 12 hours, making only a stop to fuel up, avg consumption 8L/100Km
DIESEL

Daniel

yellowrosefarm
08-24-2004, 03:59 PM
So the pump in the stern drive leg isn't up to the job of supplying the heat exchanger? As far as use, in my case, if I managed to get 20 hours of run time in a year it would be a miracle. That's another reason I like the idea of running antifreeze, no plain water sitting in the block between runs.

woodboat
08-24-2004, 07:22 PM
A little info: My last boat was a 1976 Marinete with a 360 Chrysler marine, raw water cooled running in Brackish water, the Chesapeake Bay. It had the original engine. My current boat, a 1976 Burnscraft 350 Chevys raw water cooled, one engine is the original. I don't know what happened to the original. Replacement is from Jasper, I found the reciept. Turns 350 RPM less then the original engine. Probably one of those pesky two bolt main engines :) Anyway with proper flushing and winterization as well as corrosion protection raw water engines can last a long, long time. Oh one more my 1965 owens had raw water, lived in the chesapeake it's whole life. The engine was still good in the year 2000 when I sold her. So there is a 35 year old raw water engine. If you are running in a Lake I would not bother fooling with fresh water cooling.

FAST FRED
08-25-2004, 07:27 AM
Antifreez is a very poor coolant, it has only 5/8 the heat caring cap of plain water.

Yes it is good at not freezing , raising the boiling point and has great anticorosive abilities.

If overheating is a problem only 1/3 of the coolant needs to be antifreez to obtain the anticorosive ability.

Diesels need special antifreez and should never use "car" goop.

FAST FRED

ndias
12-14-2004, 12:20 PM
Hi everyone!

marization of a auto engine is possible and in Europe people are doing it.

Try Seenergie.fr, they have a kit for DiY marinization of the PSA diesel motors Peugeot-Citroen).

All depends in what boat do you have, what for, regular use and so on.

I'm not a rich person but I manage to convert an old cargo ship lifeboat to a 7,50 meters gaffrig for 4 persons, did all the wor, sew the sails and now is marinizing a PSA motor...

greetings

ndias

gonzo
12-14-2004, 09:00 PM
What is the cost of marinizing an old automotive engine versus buying a used marine engine? In my experience a used marine engine is cheaper. If money is a problem, a custom job makes no sense.

ndias
12-15-2004, 04:06 PM
Hi

In europe boats run with inboard diesel and outboards with gasoline.
Problem that second hand marine diesel motor are veryhard to find, so or you buy a new one or you marinize.
In Portugal, the new Yanmar of 25 hp cost 7300 euros, a Bukh of 25 hp costs 9000 euros. Buying a PSA or Opel 1500 diesel costs you 400 euros and a PSA motor from France with the marinizationdone from factory costs you 4700 euros.
I bought an Opel for 400 euros and the kit (tachometer, hourmeter, voltmeter, raw water pump and heatexchager) for 300 euros, if you put some gaskets and joints, I can for 800-900 euros have the motor marinized.

Richard Petersen
12-15-2004, 04:07 PM
I think Gonzo is totally right on this if the engine is a brand that has never been marinized. I want to use a Infinity V8 or a Nissan Titan V8 - same basic engine. I trust the engine more than any other. The amount of time and money is proving to be a lot more than expected. Plus I and a bunch of experienced guys are going to have to buy- layout- fit- mount- take off- refit- the brackets for a lot of parts to mount on the engine. It is not a project to start unless you have people who like to help others. AND have the talent not to take short cuts when it bogs down. We thrive on bringing back to life any " dead boat ". Money- just have 3X more than you would think you honestly estimated. Do it with others, safety AND more ways to solve a toughy. Rich -------------------Here is a surprise I just heard, Cadillac is now ordering dealers to toss any new blocks that need a rebore of any amount, as they are casting wall thickness only to meet warrenty life expectations. Big volume is going to close a lot of good independant marine rebuilders. We have all been lucky to live in the age before real cost cutters take control of all we love to do with our boats and engines. If I were 25 I would buy a couple (6) GM marine long blocks- correctly prepare them for long storage and use them as a pension fund which will definatly go up faster than money. Anybody have any perfect Deusenberg engines? Rich

brian eiland
12-17-2004, 12:13 AM
The Dec/Jan 2005 issue of Professional BoatBuilder has a really excellent article on the subject of diesel-electric propusion by Nigel Calder

Tater
02-01-2005, 04:13 PM
Alright, I've read through this entire thread and have seen it start off with if auto engines can be used in marine applications to attacking people's knowledge to attacking people countries. Seeing how this thread shows up at the top of the results for a Google search on this issue and I'm sure more people would be interested in hearing about this topic, I believe it behooves us to get back to the topic at hand and really work out the details. I really want to know how much better it might be (if at all) to drop something like a Chevy 350 in place of a Mercruiser equivilent on a 20+ foot small powerboat cruiser.

I'm quite sure the US has more regulations on boat design than other countries, probably to keep marine companies from being blamed for too many accidents. However, I think there's some reasonableness to installing fire/spark suppression systems onto a marine engine. There isn't the realtively free flow of almost constantly moving air throughout a marine engine compartment as there is in an automobile. My question is this:

"Is it possible to alleviate this problem by installing new or used marine alternators/air filters/starters/whatever else onto the auto engine? Is this cost effective or more trouble than its worth and why?"

There is a lot of debate about the durability of a standard automotive engine versus that of a standard marine engine. I'm hesitant to believe anything coming from the manufacturer since they would much rather you spend the extra $$ on a proper marine engine than finding a rebuilt automotive one. My question:

"Is it possible if you chose an engine that was significantly more powerful than the minimum amount of power required to sustain a boat at a reasonable speed AND you geared that engine for a reasonable RPM at wide open throttle AND you chose a properly matched propeller, would that particular engine last a reasonable amount of time" (sorry for the overuse of the word reasonable)

I won't even touch the cooling issue because it seems that can be accomplished using already exsiting closed-system cooling equipment. But, please let me know if I'm wrong.

Thank you
Tater

Danielsan
02-01-2005, 04:44 PM
In a general way that is what I thought also. Some people have me made to change my mind and not to do it.
But still, last night I ran into some used BMW850CSI engines rated 450HP >400Nm torque.
Indeed using the Ex(x) certified alternator and starter would be the only thing to change.
I was even more on this because I would use a jetdrive, so thrust bearing, etc wouldn't be neccessary anymore???

Greetz,
Daniel Peeters

One thing not to forget is all the (high) tech ignition system of a good recent engine. But a good engine tuning shop can do the job well.

Richard Petersen
02-01-2005, 06:06 PM
The answer is YES. Any engine will power the boat. The remaining YESES require YOU to know how to do it, or someone else with the knowledge and ability. If you are still answering YES, you do not need help. All those who have a NO at this time need lots of reading and homework to have a good chance of pulling this off safely. In my personal opinion I would remove every all the fuel system and computer system and ignition system. Replaced by a MARINE carburator of the correct C F M. A MARINE distributor, M S D is a simple 3 wire hook up with a REV LIMITER. The engine is now running reliably, and USCG legaly safe. At this point we start the how long do you want it to LAST in fresh or salt water. Be back. Supper calls!!!! :p

woodboat
02-01-2005, 06:54 PM
On every marine engine I have used there is a lot more than the carb and alternator. That has really beem discussed almost to death. In my case, a small block chevy, the block and crank are different. now I have used a car engine and it out lived the boat. The thing is though I had a proper marine engine as a donor. So I pulled the marine pan, dipstick, valve covers, intake, carb,starter, alternator and entire cooling system and placed on the car engine prior to installing. See you have to control fuel (carb, fuel pump....) then you have to control gases (dipstick, valve covers.....) and also spark(alternator, distributor, starter.......). All this and you typically have a less reliable car version of a power plant. So if you can afford a proper marine engine then install one. If you are looking for a stop gap intil you can afford a proper engine then choose the car version of what you have now to use as a donor. If your looking to due it from scratch I doubt that you will save any money by the time you buy the marine parts and will have a weaker engine when finished. At least this is the way I see it :)

gonzo
02-01-2005, 07:29 PM
Here is one significant difference: top ring gap in automotive engine-.035" top ring gap in marine engine-.080. It accounts for the higher piston dome temperature.

tom kane
02-01-2005, 07:41 PM
My criteria for DIY Auto Engine Marinization is..
Safety for myself,family and Public is paramount,along with using good engineering practice.
You are legally obliged to comply with local Boating Regulations even though the Regulations may not be up to date or even sensible and anti-competative.
If you can afford what is supposed to be the best of anything,by it and try it.
If you are not satisfied with what is available,try to modify it to suit and or make your own model,and if your model is not legal,try and get it recognised.This is what usually happens anyway.
Some of the best ideas come from people who know nothin about a particular subject,as just about anything can be made to work.

Tater
02-01-2005, 09:27 PM
Thank you all for your quick response. I'm starting to believe that it might initially look as if you'll save time/money by using an automotive engine, you're probably much better off just sticking with the original and having it rebuilt. It seems like this would, in the long run, be much less stressful. I suppose if I had an old engine lying around it would make better sense to give it a try....Does anyone concur?

Richard Petersen
02-01-2005, 09:35 PM
A marine engine is the right way to go. :)

Corpus Skipper
02-01-2005, 10:05 PM
In my case, a small block chevy, the block and crank are different
Sorry Woodie, but I just can't let that one go. I have rebuilt dozens of Chevy 350s, auto, truck, and marine. They're identicle. The marine engines are merely the truck, and or factory high performance engines. They have 4 bolt main bearing caps, found in trucks, Chevelles, Novas, Camaros....., they have forged steel cranks (sometimes), also found in cars/ trucks, and higher output camshafts, high performance/ truck rods, and double roller timing chains. Reverse rotation engines are the exception, having a gear drive rather than a timing chain, so that the distributor/ oil pump turn the right way, and the pistons are hung 180 degrees from norm. The only things that differentiate a "marine" engine from a GM factory truck/ high performance engine are the accessories, as Richard pointed out, and ring gap, as Gonzo said. You could pull a Mercruiser 350 out, swap the carb, ignition, alternator, etc.... on to a 350 from an '85 Silverado, overhaul it, regap the rings, and have the same thing you got from Mercruiser. End of rant. :D

woodboat
02-01-2005, 11:15 PM
I specifically wrote "car"
Additionally it isn't the only thing different. The ring gap thing is huge. The cam is different also. Yes, one could build a truck engine to marine specs but we wouldn't be saving any money so what is the point? Note I have used a true car engine with 300,000 miles in a boat. Wasn't pretty but it worked. It was a tired old 307. I put in some new stuff but the cam bearings were pitiful so oil pressure was pretty low. Again it worked but there really is no point. I did all that work swapping it in and got a tired old motor. Only reason it made sense was it was a tired old 26ft plywood trojan that we cut up two years later. We've been round and round. My assessment still is that the low price point for a small V8 chevy means that swapping in a car engine just isn't worth it.

woodboat
02-01-2005, 11:22 PM
I did a quick search. This is from an engine remanufacturer.
Fileman sells engines in 24 states, but does not do any retail business. He only works through dealers and distributors. "There are a lot of marine engine builders in Florida, and a lot of automotive rebuilders who are trying to do marine engines. But many of these people have little or no experience in the marine market and try to sell a passenger car engine as a marine engine for as little as $600. Those kinds of engines won’t hold up because they don’t use marine quality parts.

"Marine applications are very demanding, and there’s no way to build a marine engine inexpensively. You have to use top quality parts. One hundred hours in a boat is roughly the equivalent of 25,000 miles in a car because you’re often at full throttle under constant load." Fileman said he sells a Chevy V8 marine engine for $1,200 to $2,000 with a one-year warranty on engines rated up to 375 hp.

from here http://www.aa1car.com/library/2003/eb60342.htm

woodboat
02-01-2005, 11:24 PM
this one mentions thicker castings on the heads as well as cam differences
http://www.asme.org.vt.edu/docs/asmenews78.pdf

ndias
02-02-2005, 03:36 PM
Yes Tater, you're right...

many countries many laws, but the sea remains the sea.

With time and if you are a guy who likes to do everything on board, you can get an auto engine and get a new one for your boat and I asure you that is money worth.

best regards

Nuno Dias (Portugal)
I myself did from a grp hull of a lifeboat a gaffrig cuter (www.geocities.com/ntbrd68)

Richard Petersen
02-02-2005, 04:38 PM
Please do not worry! All those who need to go fast. You will only have to pay more for the same speed. GM is quiet. Not dead.

Richard Petersen
02-02-2005, 04:42 PM
What are the present legal loop holes for marine engines? This engine is carbed because of--- this one is --- because of---. Does anyone know?

Tater
02-03-2005, 10:30 AM
Check out this quote from the "About" website:

"Most gasoline inboard engines are a version of a truck or heavy duty industrial engine. Remember, your car gets to coast going downhill, but your boat engine is pushing uphill all the time. Also keep in mind that a boat engine is driving the hull through a heavy fluid, not just air."

So it would seem that a person would need to modify an automotive engine to heavy-duty specs before using in their boat. I think that's been the message most people have tried to get across here anyway. Given this information, I think its at best unwise economically to try to use an automotive engine in a marine environment. Seems like it would be much more simple/economical/reliable to use your old marine engine or find an equivilent replacement.

Danielsan
02-03-2005, 11:30 AM
do you mean the ordinairy GM engine with some 100-300? HP with a torque similar to that of a lawnmower?

Or do you mean some high end engine with +400HP with some equal amount of torque?

just a question.

the cars I used to drive didn't use to run with carbs or mechanical ignition syst. Not completely true my 1982 BMW320 had a modified 4 doubl weber carb, it didn't have mechanical ignition system. I never had one

So let's say, this is 2005 are there still new engines sold with such an old technology?

I hope not,

tom kane
02-03-2005, 02:47 PM
There are lots of these 250-300 HP light weight auto engines as standard modified for marine use being used in boats,and they have the latest teco,like adjustable cam and many goodies.There are thousands in wreckers around the world.

Danielsan
02-03-2005, 03:05 PM
Yes I think this IS common stuff for many people who dont have the money or who have a good idea at what they are doing.

Why does this thread allways come up with the use special marine carbs, I don't know why because any recent engine has EFI syst or is diesel. the only

I can agree with are the spark free starter engine and alternator. Even when I talk about a automotive engine, I am talking about the more high end engines whith good HP and good torque. Not a simple 1.8l gas engine with with some high HP and some shitty torque curve.
What I want to say is that some engines are almost standard race engines, put a modified controll unit, marine alternator and marine starter on it use a good thrust bearing or jet unit and let it rock.

I know that I will do this for a test because I cant spend 20.000,00EUR on a engine to see if my boat goes well.

Greetz,

Daniel Peeters

If someone could/would sell me a working marine engine for the price I get my automotive engine I will get on it (2.000,00EUR)

Richard Petersen
02-03-2005, 06:09 PM
I have been on a Nissan forum trying to find out how easy it is to pull a Nissan Titan V 8 out of a pickup truck an toss it in a boat. GOOD dealer mechanics are not completly sure if it would run as well in a boat because of continuous duty we have. IT will trigger a failsafe to 1/2 power due to continously high exhaust temperature. Other sensors will also sense this and 1/2 power the engine. Cheapest and most reliable way is to carb. the engine. Or play with a computer each time the battery is removed and the computer resets to stock settings. Do not take these problems lightly. A new universal engine computer is on the way to eliminate more engine hackers. :mad: These are special purpose car engines , like it or not. There is no good reason why different computers are needed in cars or boats or planes. 35 years ago I designed into gas sniffing equipment circuits that would cause a shutdown if you started to take readings of the circuits parts. I would hope the autos have the same in them.

tom kane
02-03-2005, 06:34 PM
Have a look at the threads,Remote safe fuel system for boats.also,Pulsing for power in boats.

Richard Petersen
02-03-2005, 06:57 PM
Thanks.

tom kane
08-09-2005, 05:25 AM
This looks a real neat package for a boat to me.These people make it look easy.From the Thread 10M Thai Long tail.

PowerTech
08-09-2005, 11:30 PM
:p :p :p :p :p :p :p :p :p :p :p :p :p :p :p

gonzo
08-10-2005, 09:09 AM
Power Tech: you have been consistently obnoxious and insulting. This is past the limit. I will put a complain about you and request you are banned from the forum. Anybody else that thinks Power Tech's comments shouldn't have a place in the forum, please complain to Jeff too.

Frosty
08-10-2005, 09:36 PM
The picture of the engine posted by Tom Is a typical Thai engine installation. The frame can accomodate almost any engine, notice the greasing thumb screw at the output saft. All the parts required can be bought at just about any hard ware shop. Interestingly the surface propellors that they use are incredibly cheap. The smallest is approx 4 inches and is 35 Baht --42 Baht to the us dollar. machined and keyed ready to fit, (No mistake there).To every Mercruiser standing in the car park un-repairable there will be a thousand of these. Allmost all have no exhaust system and some times no manifold--ear splitting at times. These reliable installations take tourists out to islands as far out as 40 miles. I do see them being towed but its not common. Love or hate em, they are as much a part of Thailand as aquatic shows are to Florida.
The smilies are too late.

AlaskaFisherman
08-16-2005, 12:02 AM
I have used a 350 cu. in Chev in a 32 ft. commerical Fishing boat for 13 years. I run about 250 hours in July every year. The motor has been rebuilt twice since I have had it. It's a good truck motor and nothing more. Auto carb, distributor, alternator, starter, fuel pump. The starter mounts high on the flywheel housing. Flywheel housing matches the reduction/transmission. It is not uncommon for us to fish in 8 foot sea's.
It works.
Fuel pump could be a problem - up to two years ago, it was electric.

hartley
02-03-2006, 11:52 PM
Im a late contributor to this interesting topic,I realise that some of the regular contributors are U.S based and are quoting U.S regulations on marine engines ,I also feel some are pushing their own barrow business wise .
However there are many countries outside the U.S that put auto engines both petrol and diesel in boats and make them work.
Here in Australia there is a long tradition of marinizing auto engines for marine use.perhaps not as much as in past times (perhaps people have more money)
Engines that come to mind are the small English ford 10,there were numerous companys manufacturing water cooled manifolds etc,some supplying complete
packages,engine,gearbox,shaft,prop,stuffing box.then there was our own home grown product the G.M holden these were put into boats by the thousand ,and not forgetting Henrys side valve V.8 these were a firm favourite for the speedboat boys.
On the other side of the world in the U.K a firm called Lancing Marine,of which I have a catalogue they have parts to marinize just about every engine you can think of ,from mercedes 5 cylinder diesels to umpteen ford engines to would you believe jaguar DOHC engines,they supply everything bell housings gearboxes,manifolds,shafts instruments,everything you can think of,but nary a marine camshaft,special marine blocks,or other bits deemed necessary by some,good heavens I believe the ring gaps in these engines are the standard gap.So it would seem that marinizing auto engines is alive and well in some countries,
Now lets get back to some of the things deemed necessary in the U.S
stainless steel head gaskets .....why on earth would you want these in a closed cooling system,surely youre not running raw water through these engines.
special blocks with added compounds by the manafacturer.......I would have to have some some definite proof from G.M or FORD that these blocks do exist in the general market place ,to have a dedicated block line and different casting practices for the miniscule number of engines involved defies reason.
just as well ole Henry is long gone
I havent even discussed diesels yet but be assured the same applies,Japanese kubotas marinized by a host of companys,same applies for nissan,to a lesser extent izizu.
So to all you people out there wishing to marinize auto engines .Go for it.thats my 2 cents worth.............Good luck.

tom kane
02-04-2006, 02:47 AM
Here in New Zealand we (Industries leaders) are thinking of following Australian Regulations in regards to some recreational boating Regulations. (how you are allowed to build boats).What do you think hartley,about your Regulations.Some of the old boat motor instalations had some prety hairy cooling systems (raw water) being sprayed into the exhaust manifold just a few inches from the valves (ford 10) a manufactured product.The technology now has progressed a long way,yet many modern motors use raw water aroung the motor.

Frosty
02-04-2006, 11:54 PM
I agree with you Hartley, and if what you said wasnt enough, the well known and well respected Yanmar 6LP is a Toyota engine 1hd, from the land Cruiser. The cooling system is of course Yanmar. Mine came with Toyota filters on them and if you dont beleive me,- reach round with a flash light you will read Toyota at the back of the block by the raw water pump.
This at first might seem a rip off but hey wait a minute I buy everthing from Toyota--- filters, timing betls. timing belt tensioners, head gaskets.

hartley
02-06-2006, 05:42 AM
Thanks to Tom Kane for his comments,I believe N,Zers also have a long tradition of marinizing auto engines ,but as you say Tom techonogy has moved on ,but that should not stop anybody from marinizing an auto engine if he so wishes ,after all we both live in free countries (I only hope it lasts).
As regards your query on regulations over here ,we are for better or worse a de-regulated society,Boat building over here is in the hands of a relatively few builders of high repute , the shonks have long disappeared,therefore the industry is mainly self regulated.there are of course A.D.Rs (australian design rules) but these were formulated some years ago ,and as far as I know there is no Government agency overseeing these ,Of course small alloy boats (tinnies) have to have the required buoyancy and max weight ,but there again it is industry regulated .this of course applies to recreational boats ,commercial boats are a different kettle of fish.
Safety issues are once again a different issue ,and these are very detailed and strictly policed ,covering from the smallest craft to larger offshore.
I wiil post these if anyone is interested.
Thanks to Jack Frost for his comments ,I would be interested to know what happens in Thailand re boating in general.As regards powerplants for boats in Australia these of course are all imported ,mainly from the U.S.A and Japan and the industry here accepts that these engines comply with international emmision and safety standards .......Cheers .

brian eiland
02-06-2006, 09:23 PM
..an announcement I received recently....

December 2005
YANMAR AND BMW ENGINE SUPPLY AGREEMENT
YANMAR CO LTD and BMW AG, German manufacturer of luxury vehicles, have agreed
that BMW will supply four and six cylinder Diesel engines designed for high
performance use to YANMAR MARINE INTERNATIONAL BV as the base engine for the
new YANMAR MARINE product line.

This agreement enables YANMAR to have the most advanced marine engines for its
product range. Customers will be in the position to benefit from the joint
efforts of two of the most reputable companies in their respective fields of
operation with a product that will set new standards in the Marine industry.

YANMAR is aiming to introduce this new fully electronic range of Premium
Marine Diesel Engines in the market around mid-2006.

The engine will be 'Marinized' and marketed under the Yanmar label. We have
had our eye on the BMW diesel six for 2-3 years now.Rumour had it, two
Austrians, in the vicinity of the BMW Steyr plant where they are made, have
been running the 'Hot Rod Six' in their boats. BMW's 3.0 litre diesel six
cylinder engine has received world wide acclaim from the Automotive press and
the Automotive engineering communities. BMW is recognized as the leader in
Diesel engine design in the world. Europeans can option the 'Hot Rod Six in
the 530d sedan and the X5. This engine is not available in North America BMW
vehicles. Soon, we hear.

I've always thought that the in-line six-cylinder engine was the most
inheriently balanced engine configuration for a 4 cycle engine.

Here are a few comments on same subject:


The benchmark in diesel motoring: BMW's three-litre straight-six.

BMW's straight-six features the most advanced technologies, such as common
rail direct fuel injection, a turbocharger with variable geometry and
four-valve technology. The combination of common rail fuel injection and the
classic straight-six engine configuration provides ideal conditions for a
genuine high-comfort diesel, the rapid charge cycle ensured by the high-tech
turbocharger as well as four-valve technology offering the additional
advantage of an excellent engine response: While conventional diesel engines
are usually a bit sluggish in their response to the accelerator pedal, as
opposed to a petrol engine, BMW's straight-six diesel builds up torque
spon-taneously with virtually no delay. So it is no surprise that this
six-cylinder is already featured in all three of BMW's saloon series - the 3,
5 and 7 Series - and is acknowledged in each case as the absolute benchmark in
the market.

http://www.germancarfans.com/print.cfm/ID/2040718.001/lang/eng (http://www.germancarfans.com/print.cfm/ID/2040718.001/lang/eng)

stonebreaker
05-31-2006, 06:04 PM
I've read this whole thread with some amusement. I've seen a couple of folks who seem to believe marine motors are magical and an automotive motor can never be marinized without the requisite magic wand.:D

It's like the guys I see at the car shows who think factory police motors are somehow magically unbeatable. When you try to tell them that the car came stock with the same engine as the police version, they try to claim the factories don't sell "interceptor" motors to the public; and nevermind that you've built a 383 stroker with forged internals that will put your car through the traps in 11 flat at 120 mph; you can never outrun a police car.:rolleyes:

I've also seen one or two guys who have claimed their territory and are sticking to it no matter what - like quoting stats out of context to support their position, even though the stats have become meaningless in their posts. Most of the arguments I've seen from these guys are, at best, 15 years out of date.

I don't know about the corrosion side of things, but I do know performance engines and I do know about cooling race motors.

As far as which engine is cheaper, I have to say a performance automotive engine is going to be far cheaper - about 2/3 the price. I went to two websites: http://www.sterndrives.com/supplies/mainsupplies.html and http://www.bayshorepowermarine.com/engines.html, and priced a mercruiser 350 Magnum 300 hp fuel injected engine. Discounted price was $7195 at Bayshore Power, and $8743 at Sterndrives.com. This is engine only price.

Now, I can go to a performance automotive website and price an equivalent motor. GM builds several smallblock packages off of the ZZ4 shortblock. This motor will have a nodular iron crank with nitride hardening, fuel injection, powdered metal connecting rods (these replaced the forged pink rods about 15 years ago), hypereutectic pistons (the same high silicon alloy cast pistons favored in some of the previous posts), and on and on.

Ramjet 350 crate engine (http://www.sdpc2000.com/catalog/120/products/463/Ram-Jet-350-PFI-GM-Performance-Parts-Crate-Engine-Assembly.htm)

Anyway, the price of a Ramjet 350, 350 hp rated motor with included fuel injection computer is $4895.

Here's the same engine set up for circle track racing. (http://www.sdpc2000.com/catalog/3395/GM-Performance-Parts-Circle-Track-Crate-Engines.htm) The only differences are aluminum heads for better cooling, a racing wet sump oil pan, and a carbed induction system to meet sanctioning rules. Yet, the engine is designed for circle track racing right out of the box. That hardly sounds like an engine designed for 80% throttle 20% of the time.

What does the extra $2300 for the marine motor get me?

Interesting factoids:

Compression ratio in Ramjet 350 automotive crate motor: 9.4:1
Compression ratio on the Mercruiser 350 ci 300 hp: 9.4:1

Hmm, they use the same chamber volume. Both use iron heads.
Horsepower on the mercruiser is listed as 300 hp between 4600 and 5000 rpm.
Max horsepower rpm on the Ramjet is 350 hp at 5200 rpm. However, the Ramjet makes 325 hp between 4500 and 5000 rpm. Hmm, same heads, same horsepower curve...sounds to me like they probably use similar cams, if not the same cam. Whatever, the power curves are so close as to be nearly identical.

I could go on and on, but the fact is the mercruiser and the Ramjet are the same exact motor internally, with minor differences like the oil pan to accomodate the different intended uses. They even share the same fuel injection computer - it says right on GM Performance Parts' website that the Ramjet computer was initially developed for marine applications.

So what does the extra $2300 for the mercruiser get me? Not much. Mercruiser makes a point of talking about their 4340 forged crank on the 6.2 liter model, as well as the fact that it has a custom cam - but no mention is made of stainless valves or aluminum roller rockers. I seriously doubt they're needed. GM has used sodium-filled exhaust valves on their production motors for more than a decade, eliminating the need for stainless, so the valves are the same on both applications.

So yeah, the mercruiser motors are extremely overpriced. The cheapest I saw for a rebuilt motor was $2600, which is again ridiculous - I can take a worn out block and have it machined and blueprinted, and drop a fully forged rotating assembly in it, for that price, and stroke it to 383 ci while I'm at it.

Even the ring gap argument I saw one guy make is bogus - running a .080" ring gap is just a cost-cutting measure. If they really do run that much gap, that probably accounts for the lower horsepower rating of the marine motor - that extra gap could easily cost 25-30 hp. Instead, why not run Total Seal gapless rings? The vettes racing in SCCA GT1 and GT2 classes use them, including the 24 hrs of Daytona, and have taken the class championship for the umpteenth time in a row; so their reliability has been proven publicly. The only problem is gapless rings are about $200 a set, regular cast iron rings are only about $35.

So what does the extra $2300 get me? Well, the marine engine comes with a 3 year warranty. The GMPP crate motor does not. So, what it boils down to, is I'm getting a 3 year warranty for 2300 bucks with the marine engine.

gonzo
06-01-2006, 01:11 AM
The marine version of the engine has an electric system that is explosion proof. The fuel injection is self contained and legal for marine use. The cylinder temperatures of an engine in marine use are much higher than in a car, even a race car. It is the equivalent of running a vehicle with a full load at WOT uphill for hours on end. Boats don't reach cruising speed and then require less power to maintain it. A larger gap is necessary for extra thermal expansion. It is not bogus. Also, Mercruiser engines have Vortec cast iron heads. Aluminum heads wouldn't last long in salt water. I sell new 5.7 engines for $5495.00 complete. The link to the engines you sell is advertising a base engine. The comparison is really bogus.

stonebreaker
06-01-2006, 02:11 PM
The marine version of the engine has an electric system that is explosion proof. The fuel injection is self contained and legal for marine use. The cylinder temperatures of an engine in marine use are much higher than in a car, even a race car. It is the equivalent of running a vehicle with a full load at WOT uphill for hours on end. Boats don't reach cruising speed and then require less power to maintain it. A larger gap is necessary for extra thermal expansion. It is not bogus. Also, Mercruiser engines have Vortec cast iron heads. Aluminum heads wouldn't last long in salt water. I sell new 5.7 engines for $5495.00 complete. The link to the engines you sell is advertising a base engine. The comparison is really bogus.

Bogus? Is that a scientific term?

First point: I do not sell anything. I don't sell engines, I don't sell cars, and I don't sell boats. I'm a computer programmer. So, unlike you, I have nothing financial to gain by pushing any particular engine or engineering solution, other than the satisfaction of helping fellow enthusiasts get better bang for their buck.

Secondly, the Ramjet engine is hardly a base engine. It even comes with its own fuel injection computer - it only requires a fuel supply and 12 volts and it's good to go. And it comes with the same iron vortec heads you get on mercruiser engines.

Thirdly, I've seen your "uphill at WOT" analogy posted several times. I've got news for you. Running uphill at WOT is not the most stressful thing you can do to an engine. If it were, mercruiser engines would have to run forged pistons, not the same cast pistons that GM puts into every car going out the door. Running flat out at WOT, like a race car, is far more stressful. Why? Because the higher rpm put added stress everywhere in the engine - on the valve train, on the rotating assembly, and on the cooling system.

And your statement about cylinder temps in boat engines being higher than a race car's engine, and thus requiring wider ring gaps, is not just wrong, it's DEAD WRONG! A) A race car's engine turns at higher rpm than a mercruiser engine. Thus, with more cylinder firings per unit time, the cylinder temps in the race car are going to be hotter, if for no other reason than there is less time for the cylinder walls and piston head to cool off between firings. B) Boats have raw water cooling, or at worst, liquid to liquid heat exchangers. Cars, even race cars, are stuck with liquid to air radiators. Even if it were possible to move enough air mass through a radiator to equal the same mass of water moving through a heat exchanger, the radiator would still be behind simply because water has a specific heat capacity 4 times greater than air, pound for pound. And lastly, the fact that cast, hypereutectic pistons funtion just fine in boat motors is the final proof that boat motors are not some sort of elite athlete compared to car motors. I burned holes in my stock hypereutectic pistons long ago, and moved up to forged.

If cylinder temps were all that high in boat motors, they would have to run forged pistons, just like every factory turbo- or supercharged car sold today has to run. But they don't. And your ring gap of .080 is ridiculous. This link (http://www.jepistons.com/pdf/piston_instrc4032.pdf) will take you to JE/SRP pistons' high silicon alloy piston installation guide. Scroll down to the ring gap guideline. For the MOST SEVERE race-only situation, a nitrous-injected full race motor (ya want to talk high cylinder temps?), the top ring gap is recommended to be .028" in a 4 inch bore, which is the bore of the mercruiser 300. .080" is nearly 3 times the recommended gap for a full race motor, and as such does nothing for the engine but increase blowby, which raises the crankcase pressure and costs you horsepower.

Frosty
06-02-2006, 03:57 AM
WOT for hours on end? --Mmmm your not supposed to do that. There are different HP rating for an engine, there is Max HP and there is constant rated HP wich is the HP it can give for "hours on end" , WOT --yes. Hours on end--yes,--but not both together. 80 thou??? as an engine builder --well 25 years ago, I would be reboring that one. There is a lot of hot gases and acid going down the piston skirt there. You would be relying on your oil control ring really. Are we sure the book has been read correctly, like discard at 80 thou,even that is enormous. Its not 0.8mm is it? wich is 28thou ish!!

Frosty
06-02-2006, 04:38 AM
Gonzo--Aluminium heads wont last long in salt water?? there is no salt water running through the head of a sealed cooling system. So why wont they last long then?

gonzo
06-02-2006, 09:50 AM
We are discussing raw water cooled engines. WOT for hours on end is how boat owners usually operater their boats.
stonebreaker: "bogus" was the scientific term used by you, so I thought I'd use it too;)

brian eiland
06-02-2006, 01:36 PM
A good friend of mine recently purchased a 44 Dutch motoryacht with a DAF 6 cyl diesel engine. He would like to find more info on these but it seems rather limited.

Can anybody supply more info??

tom kane
06-02-2006, 11:38 PM
Running an engine in a boat is like running an engine on a Dyno with out all of the over run stress of road work,you can run the motor to destruction if you want to,or you can run it and test it sensibly to get the best from that design.A well set up motor in a boat shoud have a good life.

gonzo
06-04-2006, 01:37 AM
A dyno would give a really good aproximation of the way a marine engine works.

yipster
06-04-2006, 02:51 PM
A good friend of mine recently purchased a 44 Dutch motoryacht with a DAF 6 cyl diesel engine. He would like to find more info on these but it seems rather limited.

Can anybody supply more info??
piet bos may have a manual (http://www.boatdesign.net/forums/showthread.php?t=1544&highlight=piet+bos) or surely can help

Frosty
06-04-2006, 11:45 PM
I was hoping that "Stonebreaker" would have come back by now. I didnt mean to take the floor away from him. He made some very good comments and backed them up. If this had been in court he would have won the case.
Personally I am not yet ready to accept ring gaps of 80 thou. The best I can find on the internet is a ring supplier that said up to 8 thou per inch of dia is acceptable. Where can I read this information of 80 thou? I read on one site that the ring gap for marine applications should be increased but by 4 thou !! I could be wrong but im not accepting it yet
I am not prepaired to accept that boat owners usually operate thier boats at Wide Open Throttle for hours on end. But if they do then its not surprising that engines can be bought so easily. It would seem that in the US you can you simply re-place the motor at any good marina. If I sold and repaired engines I too would make comments that would suggest that it was normal practise. But with my tounge in my cheek
I have never given my boat WOT, her 14 tons comes up on the semi displacement plane at approx 3/4 and then I back off. They then run at 3400 RPM,--Diesels of course.
If you put an engine on a dyno that produced Max Hp at 4800 and you kept it cool and lots of air and all perfect conditions but you ran WOT and held it at 4800RPM .How long will it live?

stonebreaker
06-05-2006, 03:08 AM
I was hoping that "Stonebreaker" would have come back by now. What did you want me to say? ;) Gonzo hasn't replied to the ring gap statement yet, and you were exactly correct about the closed cooling system and aluminum heads.

If you put an engine on a dyno that produced Max Hp at 4800 and you kept it cool and lots of air and all perfect conditions but you ran WOT and held it at 4800RPM .How long will it live? That depends on how well the engine is built. For anything OEM-built since about '93, I'd say the bottom end is capable of handling 4800 rpm, no problem, even the stock automotive engines. We've torn down 100,000 mile engines that still had crosshatch marks on the cylinder walls from the factory cylinder hone. The bearings are going to wear out faster at 4800 rpm than they would at 3000 rpm, of course, but that's going to happen with any engine, not just GM engines.

About the only thing that I would consider absolutely necessary to upgrading on a roller cam'd engine I was going to drop into a boat would be the valvetrain. GM uses very light valve springs to improve gas mileage. The problem with this is that the engine's peak performance will start to decline almost immediately. You'd never notice it if this was your family car or commuter car, but it becomes very apparent at the drag strip. By putting stronger valve springs in the motor, you improve its reliability at high rpm because the stronger springs provide more positive control of the valves at higher rpm.

hartley
06-05-2006, 05:20 AM
stonebreaker....Top marks for a informative and well researched post
particularly luuuuuuved the remarks about the "pink rods" and the ring gap
keep it up ....cheers

stonebreaker
06-05-2006, 11:57 AM
Thanks, Hartley. Re your comment that technology shouldn't stop a DIY'er, I fully agree. In fact, new technology has made it easier to do it yourself, not harder. Fuel injection, for example, solves the problems of fuel control that require a marine carburator on older engines, and solid state, distributorless ignitions eliminate another area of marinization headache. Although more expensive than the older solutions, they more than make up for this with their safety and fuel economy. Older automotive engines had a breather cap on the valve cover; modern engines have a PCV valve, which cars use for emissions control but on a boat will increase safety by reducing engine room vapors.

Another thing I like about electronic fuel injection is the precision with which you can tune your engine. It takes longer, and you have to have a computer you can connect to your boat's engine computer, but you can double your fuel economy in the long run, as well as tune for better performance with both fuel trim and ignition timing. We will often fine-tune our cars at the drag strip between runs. I've even seen some of the turbo cars re-tuning for changes in the weather! Another benefit of the engine electronics is you can set a redline rpm and the computer will prevent the engine from ever exceeding that rpm - over-revving is a thing of the past.

Poida
06-06-2006, 11:00 AM
Stonebreaker has read this thread with amusement.

I read it with confusion.

Hartley says Australia has a deregulated system.

In Western Australia laws are only passed if they can make money out of it.

There is not enough people maranising auto engines to either fine you for not complying or registering those that wish to do it. They have only started making people pay for skippers tickets because there is enough people out there to add money to the government coffers.

Safety in maranising auto engines? I have a petrol (gas to USA friends) that looks like it has a standard starter motor, carby and alternator. The chances of it blowing up?

I would say less than the chances of me getting killed by some knob head 1/2 asleep at the traffic lights, going through a red light and wiping me out.

Except that statistics show that both of those ways of dieing pale to the chances of dieing from a heart attack. My wife has told me that dieing should be spelt dying, sorry.

So it makes me wonder why a country would bother worrying about making laws about auto maranising when it's almost impossible to die doing it.

There seems to acceptable ways to die and non acceptible ways to die. If you die an acceptable way you're a hero, if you die a non acceptable way you are an idiot.

So if you are a formula 1 driver, get into an skid, hit the barrier and die you will die a hero.

If you marinise an auto engine and it blows up, your an idiot and the country will legislate against it.

I'm an idiot and I'm not even dead yet.

stonebreaker
06-06-2006, 11:26 AM
It all has to do with risk management. F1 is a risky undertaking, to be sure, but don't think they aren't regulated. Those cars have to meet all kinds of safety criteria to be sanctioned - crash worthiness, fluid lines, driver restraints, steering wheel quick release, fuel cell, driver's helmet, even the driver's clothes must meet minimum safety standards, and that's just the stuff I can think of off the top of my head. So yes, racing's inherently dangerous, but they don't take needless risks.

Running an automotive carb on a boat is a needless risk, because there's a better solution available.

tom kane
06-07-2006, 12:09 AM
It sounds like you have fun stonebreaker,do you use air-assisted EFI technology?

stonebreaker
06-07-2006, 01:18 AM
What do you mean by "air-assisted"? I'm not familiar with the term.

tom kane
06-07-2006, 04:35 AM
To improve injector performance,by injecting high pressure air along with the fuel spray,greater atomization of the fuel droplets can occur which is especially helpful in improving engine performance and reducing emissions at low engine speeds.Studies have shown that the short burst of additional fuel needed for responsive transient manouvers can be reduced significantly with air-assist fuel injection due to a decrease in wall wetting in the intake manifold and on a 3.8 litre engine with sequential fuel injection air-assist reduces HC emissions by 27 percent during cold-start operating conditions.Wide open throttle with air-assist and a air-fuel ration of 17 the HC reduction is 43 percent when compared with a standard injector.more..for performance enhancement mixtures...economy..Google search air-assist EFI.

stonebreaker
06-07-2006, 12:19 PM
Sounds interesting. The nice thing about technologies designed to increase fuel efficiency is that they can also usually be used to increase performance - EFI being a prime example.

Thanks for the tip!

Frosty
06-07-2006, 10:33 PM
I googled air assisted EFI and got some stuff that sounded a bit like yours but not right on. There was a couple of sites on Aprilla scooters but Im sure you didnt mean that one. I did see a couple on Air assisted direct fuel injection though. Now this raises a few points that I cant get to grips with. If it is direct why is the inlet manifold wet? High pressure air injected along with the fuel helps atomization of fuel droplets?. I thought droplets of fuel was a no no. Infact the old Lucas injection systems that I understand the cylinder would be dead if the injector was not atomizing its fuel perfectly. Air fuel ration of 17,--- now im not picking spelling here but I assume thats ratio? and the 17 bit? I thought that an engine would have difficult in running at such lean mixtures.?
And finally is the injection of high pressure air at the same time as the fuel is injected or after. Raising questions that the air injected will increase compression ratio just before injection wich would of course increase efficiency with out the extra load from the engine to compress it. Or is it as the burning process is alight meaning extra oxygen to the process?
All very interesting stuff.

stonebreaker
06-07-2006, 11:54 PM
Read a paper on air-assist EFI at http://www.hait.ac.il/jse/B/vol0201B/l040714.pdf . Seems pretty interesting, but kind of complex. GM currently solves the fuel vaporization problem by spraying the fuel directly onto the back of the intake valve, which both cools the intake valve and evaporates the fuel. I understand the next evolution in injector placement is direct injection - putting the injector orifice directly into the combustion chamber. I don't know if air-assist would help with that or not.

tom kane
06-08-2006, 12:08 AM
Air-assist fuel injection nozzle-Patent 4693420 www.freepatentsonline.com/4693420.html-37k
Oxygen enrichment for air-assist type fuel injectors-Patent 6397825
www.freepatentsonline.com/6397825.html-22k
There seems to be many people trying things like this all over.Air plus fuel injection.Cam less motors that dual rotate in two or four stroke mode and run on two or multi cylinders.
You should find Uninterupted torque for motorsport or marine interesting at www.zeroshift.com

Frosty
06-08-2006, 02:33 AM
Ahh camless motors now theres a thing. I think I am right in saying Bosch are leeping ahead with this throw off from common rail injection technique. The ultimate control of an injectors timing and duration has now been carried on to valve control. No cam,no chain, no rockers, less friction, less noise, and no need for oil up top I suppose. Coupled with the ultamate variable control of valve timing ,lift and duration>. And yes Tom I guess you could run 4 stroke or 2 stroke (if it was a blown engine with common rail injection) along with safely disabling a cylinder or two for economy. Hey --fit another starter and with a flick of a switch it would be reversable-----Fantastic
Eerr with all this exitment we got off the thread,-- but I guess you could put it into a marine engine. I personally would like some guarantees on reliability. I assume that it would be a "safe engine' in so much as should an electronic failure occur the engine would not destroy itself amongs half open valves.

stonebreaker
06-08-2006, 03:11 AM
Tom,

I don't know about the oxygen enrichment. Racers use nitrous oxide instead of pure oxygen injection because injecting even a small amount of pure O2 will melt pistons - it burns too hot. the nitrous burns slower than pure O2.

Jack,

Check out http://www.coatesengine.com/look_mom_no_camshaft.html

fasteddy
07-15-2006, 05:23 PM
Nitrous is just a way of getting more oxygen into the system, so you can burn more fuel. It's just a way of getting around the air flow limitations of the intake, and it's VERY cold, which chills (makes more dense) the rest of the intake charge. You have to inject fuel with the nitrous to maintain your air-fuel ratio (afr), or you'll pooch the motor quickly.

I'm about to build a 400ci small block 4 bolt main chevy (4 bolt main 400's are rara avis) to bolt in place of a 305 in an old Cobalt Mercruiser 888. I plan to use Manley stainless valves, a 5.7 marine cam, copper head gaskets, Mahle forged pistons fitted a tad loose with tops heat shield coated and skirts low friction coated, Clevite premium bearings, remote oil cooler and filter, and marine exhaust. Fuel management will be by a Megasquirt tunable FI system on an MPI manifold (probably GM with flow improvements) or a big block TBI. I'll probably run 8.5:1 compression. I'll use either GM pink rods or aftermarket performance rods.

I'm a little up in the air over getting a forged crank. Cast cranks take shock loads better than forged. Forged has higher rpm strength than cast, and higher ultimate strength (same thing, I guess). I've successfully used cast cranks up to 550hp in a 350ci, but only for hot street use, not marine or race.

In any case, I'll tuftride/nitride/jetspray the crank journals.

I'll use a true double roller timing chain or a gear drive, too, and hydraulic roller lifters with just enough valve spring to keep the valves from floating at 6krpms.

There are SBC blocks of many different casting strengths. Mine is a thick walled old truck motor, with 10% tin and 10% nickel in the cast iron for strength and corrosion resistance. Many GM blocks stink even for light car motors.

Show me a Volvo Penta 5.7 built that tough...

marshmat
07-16-2006, 12:08 AM
Re: EFI
Ok, let me get this straight: I hate carbs. I hate having to adjust the jets every time I change altitude, or between 15 C April weather and 35 C July. So you can see how I'd be a fan of EFI. Especially as a computer-savvy modern techie. Still prefer diesel though....
I've seen the air-assist idea a few times, it looks interesting. Some of the big carmakers (I think Mercedes was the last one I saw) have been making big progress with direct-injected engines; one of the Mercedes (I think) ones they were boasting about had a "stratified charge" mode that could run at air/fuel ratios as low as 40:1. It ran great in Europe but apparently blows up in minutes when fed on Canadian gasoline.
A big barrier right now to these advanced technologies, at least to a North American, is our sulphur-laden, cruddy fuels. Canada's starting to mandate cleaner fuel and the US is making progress, but there's still a lot of neat stuff that just can't be made to run reliably on poor quality fuel. And in Canada at least, most of us balk at the thought of paying even a few cents extra for premium grades.

brian eiland
07-25-2006, 08:53 PM
Maybe we will have a new candidate for marinizing?

Descendants of backhoe engine try for diesel land speed record

The JCB DIESELMAX vehicle, developed by U.K.-based heavy-duty construction equipment manufacturer J C Bamford Excavators Ltd., aims to break the world land speed record for a diesel-powered automobile in August 2006 at the Bonneville Salt Flats, Utah. Powered by a pair of advanced 4-cylinder, 5-liter JCB444-LSR (land speed record) diesels, developed with the support of vehicle system and powertrain technology provider Ricardo, the JCB DIESELMAX boasts the world’s highest specific power diesel engines used in any automobile application.


Interestingly, the JCB444-LSR engines exhibit many of the technologies that are likely to form the basis of the next generation of high-performance, low-emissions diesel engines in both automotive as well as heavy-duty applications. At the same time the JCB DIESELMAX engines retain excellent fuel efficiency and very low emissions through the use of advanced combustion control and diesel particulate filter technology.

JCB originally approached Ricardo plc in 1998 with a brief to design a totally new engine, the JCB444, to power JCB products. The design targets called for robust construction, a long stroke to facilitate high torque at low engine speeds, reduced noise levels, and future-proofing for the next steps in emissions legislation. The land speed record engines are developed from, and share many components with, the standard JCB444.

Ricardo applied its state-of-the-art powertrain computer aided engineering software to the task of assisting JCB in the development of the advanced JCB444-LSR engines which power the JCB DIESELMAX. Ricardo was also able to draw upon extensive knowledge and experience of the engine architecture as a result of its previous role as concept engineering partner on the production JCB444 engine.

“These were worthy aims for an engine intended, among other things, to use its weight to balance a backhoe, but on the face of it, some of them were contradictory to development of the unit as a racing engine,” says Ian Penny, Ricardo’s global director of diesel engines.

Therein lies the technological fascination and validation inherent in the JCB DIESELMAX program, which was built around the racing engine using the standard block, cylinder head, and bedplate (albeit with some lightening) in order to showcase the extraordinary versatility of the standard engine.

“Our intention all along was to use a standard block, cylinder head, and bedplate,” explains Dr. Tim Leverton, JCB group engineering director with board responsibility for JCB Power Systems. “I wanted it to have exactly the same fundamental architecture as the JCB444 engine.”


The standard engine — the only one of its kind in the world designed specifically for its industrial application — has already set new marks for power output and reliability in service.

During the course of development of the LSR version, the standard engine demonstrated the ability to cope with the very high cylinder pressures generated by the two-stage turbo-charging necessary to boost the normal 120 bhp power to the 750 bhp that will be needed to push the twin-engine JCB DIESELMAX streamliner beyond 300 mph.

“The whole project has been a fantastic engineering challenge,” Penny says. “Once we had defined the engine concept in January 2005, our effort then focused on validating and refining that concept. Initially we tried single and then two-stage turbo-charging, having taken the view to avoid more esoteric methods of boosting power. As a result, we have advanced technology in the engine, particularly in the combustion chamber design where Ricardo has deep experience, that will filter through to JCB products, and to proprietary production cars, within the next five to 10 years.”

Matt Beasley, Ricardo’s project director with specific responsibility for the JCB444-LSR engine’s development, says of the project, “The greatest challenge was how to get sufficient air and fuel into the engine to increase its power, and to manage that air and fuel flow and the associated heat generated by two-stage turbo-charging at six bar.”

Besides the block, head, and bedplate, the JCB444-LSR engine also uses the standard valve train, but with stronger springs and different exhaust valves. The crankshaft and camshaft are lightened, while the pistons and connecting rods are bespoke.

“One of the major areas of development has been the piston design,” Beasley adds. “The engine places very high mechanical and thermal loadings on the aluminium pistons, and we spent a lot of time refining the design. Aluminum normally degrades rapidly with such high temperatures. We experimented with a number of profiles. Since then we have focused on refining the other key areas — the lubrication and fuel systems. The former is totally new as the engine is inclined at 10 degrees from the horizontal for optimum installation in the car. There is a lot of oil flow, up to six times what you would expect in a normal diesel engine, and the oil circulates around the engine every five seconds.


“The fuel system is also remarkable. We have achieved 750 bhp after going to gold fuel pumps in place of the previous red pumps, and by very careful attention to the injection system. We are putting a tremendous amount of fuel through very small orifices in the injectors, and are doing so at massive pressure — 1,600 bar — hence the magnitude of the engineering challenge in that area.”

Test “mule” engines ran for as long as 12 hours during the development phase, and some were stressed to destruction in order to see where the limits of individual components were.

“They were impressively high,” Penny says.

The definitive JCB444-LSR engine displaces 5 liters, weighs 382 kg (dry), and produces 750 bhp at 3,800 rpm on a relatively low 10.5:1 compression ratio and in excess of 1,500 Nm of torque at 2,200 rpm.

“I am confident that the JCB DIESELMAX will easily be the cleanest and most efficient land speed record car ever built,” Ian Penny adds. “The car has twice the power and more than four times the weight of an F1 car, yet half the fuel consumption.

http://www.jcbdieselmax.com/html/home.php (http://www.jcbdieselmax.com/html/home.php)

http://www.ricardo.com/ (http://www.ricardo.com/)

stonebreaker
07-27-2006, 02:55 PM
I'll probably run 8.5:1 compression. I'll use either GM pink rods or aftermarket performance rods.
Why are you planning on running compression so low? Are you going to run forced induction?

BTW, GM no longer makes the pink rods - they use sintered metal instead, even stronger than forged. They come from the factory balanced to +/- 1 gram on each end.

fasteddy
08-03-2006, 01:31 PM
Yup. Going with twin mitsu 12A turbos.

stonebreaker
08-03-2006, 01:57 PM
You sure you want to run factory rods? I would have thought you'd be better off with some H-beams on a twin turbo setup like that.

bobby4244
09-07-2006, 11:53 PM
Greetings! Just finished reading this entire trend. So, I had to join ! Guess I'm the new kid on the block ( if 60 is a kid?) Well, I might be the worlds oldest living teenager anyway !!

This trend has been very interesting, to say the least. And it just so happens that My son and I are putting a car motor in a boat so I am all ears.

The last one that I did was my 19 ft that came with a 307 225 hp chevy OMC I put a car 400 smallblock bored 30 over. and used the "151" chevy cam (350 hp 327 cam). The 307 had the 300hp 327 "929" cam. I used flat top pistons. the extra cubes didn't seem to make much difference, it still does about 50 mph. And yes, I tried different props. Anyway.........

Son just bought a 1988 20 ft. with cracked 305 and we are putting in a 1991 305 car engine. We are making the necessary changes to marinize it but I am unsure as to the cam profile to use. The 1988 motor uses a hydrolic flat lifter and the 91 motor has a roller cam. The IO is a OMC cobra and It calls for 4000 - 4400 WOT RPM. The 88 motor had a double roll timing chain and I cannot seem to find one that will fit the roller cam. From my last experence with the 400 - 307 changeover , it seems that OMC used a oem chevy camshaft but not the same one that would normally be installed in a 307 for a car. I have no desire to purchase an aftermarket cam. I would like to stay with GM parts. Will the 91 car 305 rollercam perform ok? Or did OMC use a different cam? I presume that at some point in time OMC must have started using the roller cam in their Chevy cams. Any suggestions? Many thanks. :)

Frosty
09-08-2006, 12:17 AM
Oh boy this should be good (pulls up chair closer to lap top). Do you know what you have just done? You have lit a fuse !!!

But why do I think you know that? welcome to the forum.

bobby4244
09-08-2006, 12:32 AM
Yeah, I know what I done!:eek: I figured I'd come in with a BIG BANG!!!:!:

bobby4244
09-08-2006, 12:39 AM
or a BIG SPLASH !! Thanks for the welcome :)

stonebreaker
09-08-2006, 01:13 PM
Greetings! Just finished reading this entire trend. So, I had to join ! Guess I'm the new kid on the block ( if 60 is a kid?) Well, I might be the worlds oldest living teenager anyway !!

This trend has been very interesting, to say the least. And it just so happens that My son and I are putting a car motor in a boat so I am all ears.

The last one that I did was my 19 ft that came with a 307 225 hp chevy OMC I put a car 400 smallblock bored 30 over. and used the "151" chevy cam (350 hp 327 cam). The 307 had the 300hp 327 "929" cam. I used flat top pistons. the extra cubes didn't seem to make much difference, it still does about 50 mph. And yes, I tried different props. Anyway.........

Son just bought a 1988 20 ft. with cracked 305 and we are putting in a 1991 305 car engine. We are making the necessary changes to marinize it but I am unsure as to the cam profile to use. The 1988 motor uses a hydrolic flat lifter and the 91 motor has a roller cam. The IO is a OMC cobra and It calls for 4000 - 4400 WOT RPM. The 88 motor had a double roll timing chain and I cannot seem to find one that will fit the roller cam. From my last experence with the 400 - 307 changeover , it seems that OMC used a oem chevy camshaft but not the same one that would normally be installed in a 307 for a car. I have no desire to purchase an aftermarket cam. I would like to stay with GM parts. Will the 91 car 305 rollercam perform ok? Or did OMC use a different cam? I presume that at some point in time OMC must have started using the roller cam in their Chevy cams. Any suggestions? Many thanks. :)
Try Summit (http://store.summitracing.com/egnsearch.asp?N=700+4294925232+4294892074+115+4294908216) for the roller timing sets.

For the cam, you might try Crane. Crane Cams is the OEM supplier to GM, and they have a pretty good selection of both automotive and marine cams. Their online help is pretty good, too. www.cranecams.com If you want to stick with a GM spec cam, however, you might look at the GM Performance Parts cam p/n 14097395. It's got short duration but a tight lobe separation angle, and makes big, big torque.

fasteddy
09-08-2006, 06:15 PM
Yup, torque is what you want, since you aren't winding the motor to 6k rpms, I'd think you'd want your torque peak right around the cruise rpm or a few hunderd rpms lower, right? That's the most efficient point in terms of volumetric efficiency. The torque/hp relationship is:

HP = (torque x rpms)/5252

so you might see higher hp numbers at higher rpms, but you'll never use those high rpms (at least not for long - bang-clank-clank-clank).

I think you might find a better cam choice for the 400 than the stock GM car/truck cams. And why fool with another 305-307 at all????

bobby4244
09-08-2006, 10:13 PM
Try Summit for the roller timing sets.

For the cam, you might try Crane. Crane Cams is the OEM supplier to GM, and they have a pretty good selection of both automotive and marine cams. Their online help is pretty good, too. www.cranecams.com If you want to stick with a GM spec cam, however, you might look at the GM Performance Parts cam p/n 14097395. It's got short duration but a tight lobe separation angle, and makes big, big torque.


Thanks Stonebreaker, I'll call Summit tomorrow. As far as cams, I am aware that Crane is making GM cams and I have already called their tech dept about a week ago. They reccomended cam and lifter set PN 113502. for my boat with the 400 cid. I am leary of taking someone elses openion on cams. I once had a bad expierence years ago. I tried a Compatition Cams 278H , I think it was, in my 64 SS IMPALA Conv. 327 4 speed , 202 valve fulie heads Forged crank and pistons , Torker intake etc etc. The guy at the speed shop told me it would make my car really go. All the cam did for me was idle kinda rough . I pulled it and installed a chevy "151" cam and the car screwed! And the idle was smooth! Beleave it or not, I used to beat big block Camero's with that heavy car! For this reason, I installed the "151" in my 400 in the boat. The boat with the 400 and "151" cam does pretty good (50MPH) but I feel it could do better and the problen might bee the cam due to the 151 being a higher rpm cam. I think I might need a cam that makes peak torque around 3800 - 4200 RPM. Does this sound right to you and what cam would you suggest? According to my books, the 151 makes peak torque of 360 ft.lbs. at 3600 rpm and thats in a 327 cid with 11/1 CR and fulie heads etc. In a 400 inch engine with flat tops and 75cc chambers,I suspect the peak torque is at a lower rpm.

As far as the cam number you suggested, I tried to find it in my books but can't. Do you have the specs on it? Is it a roller cam? We are talking the 305, right? I really need some good tecnical input in the cam thing as I feel strongly that picking the right cam is vital. The rest of the motor is done right (I know what I am doing) . Just the cam thing gets confusing and I havn't the extra money to go tring different cams till I find the right one. One question is , if top rpm for both boats is 4400rpm then at what rpm do I want to make peak torque? And the 400 cid boat has to have a smooth idle down to about 550rpm as it has electric shift. Many thanks for everyones efforts to help.

bobby4244
09-08-2006, 10:55 PM
Yup, torque is what you want, since you aren't winding the motor to 6k rpms, I'd think you'd want your torque peak right around the cruise rpm or a few hunderd rpms lower, right? That's the most efficient point in terms of volumetric efficiency. The torque/hp relationship is:

HP = (torque x rpms)/5252

so you might see higher hp numbers at higher rpms, but you'll never use those high rpms (at least not for long - bang-clank-clank-clank).

I think you might find a better cam choice for the 400 than the stock GM car/truck cams. And why fool with another 305-307 at all????


THANKS EDDY, but my motors don't blow! And peak RPM will not exceed 4500rpm . But I am one of those guys that rarely cruses. I want SPEED!!:D
Currantly, the boat with the 400 does 50mph with a 21 pitch cupped prop.
and one person on board. it is 18.5 ft long. I would like to see at least 55 MPH! And more is better but I would be happy with 55. I also don't want to use more gas than it uses now. :mad: I think I would want peak volumetric efficiency at a little higher RPM as the boat isn't babied. I live on a lake and sometimes I trailer it to the salt water.

Why bother with a 305? Cause!! :P I was able to pick up a 305 much cheaper than a 350 and 400s are getting rare. And the 305 boat doesn't need to go that fast. 35 - 40 mph is fine for this boat. Economics was the main reason and the cracked 305 has many good parts in it. It had just been rebuilt just prior to the freezeup. New .040 over pistons etc. Soooo if I need to rebuild the new 305, I already got the parts! I think thats a pretty good reason to "bother" with a 305. Otherwise my choice would have been a 4 inch bore. As far as 307, it wasn't a bad motor at all! It was a 283 block with a 327 crank (3.25) A 307 will walk all over a 305 and it has heavier walls etc.

Many thanks for your thought and efforts.

I REALLY DO NEED HELP CHOSING THE RIGHT CAM FOR BOTH THESE BOATS!:o

stonebreaker
09-09-2006, 12:22 AM
Bobby,

Take a look at http://www.gmgoodwrench.com/perfpartsjsp/_res/pdf/gm_performance_parts_catalog_2006.pdf this is the online GM Performance Parts catalog in Adobe format. Cam 14097395 is used in GM's 383 high torque crate motor. It's very similar to the cam that came in the 94-96 impala ss LT1 engine. It has a little more duration and a little tighter lobe separation, and is probably what GM would have used in the impala stock if not for emissions. It's listed as 196 intake 206 exhaust at .050 lift, with a 109 LSA. The GMPP catalog says the High Torque 383 is good to 5000 rpm.

Some other cams to look at for the 400 are GM part numbers 12370845 and 12370846. The 845 cam is good to about 5500 rpm, and the 846 cam is good to about 6000 rpm. The 846 is the cam used in the ZZ383 engine. The numbers for the 845 are 214/222 at .050" and 112 LSA with 5 deg advance ground in, and the 846 is 222/230, also with 112 LSA and 5 degrees of advance. I ran the 845 in a 350 ci LT1 in the impala, and it idled nicely at 750 rpm and got 22 mpg on the highway. It also passed emissions on a treadmill afte we set the idle to 950 rpm. Some of my friends ran the 846, and it has a nice, cammy idle but I think it was a little large for the 350 - it didn't make the car any faster than mine with the 845 in it.

I'm currently running Crane's part number 109227 in the impala. 210/224 duration at .050", 112 LSA and 5 deg advance ground in. It idles smoother than the 845 - you can't even tell the engine has a cam at 650 rpm - and has about the same rpm range as the 845. In my 350 LT1 with ported heads, it makes 362 ft/lbs of torque at the rear wheels at 3200 rpm and 320 rear wheel hp at 5500 rpm. The car has run a best of 12.6 at 108 mph at a race weight of 4500 lbs on pump gas.

bobby4244
09-09-2006, 12:50 AM
All those above figures look pretty impressive to me. And I did find the specs on the 395 cam while you were posting. It looks like a perfect cam for the 400 but, but! my 400 isn't set for a roller cam :( And I have to have a smooth idle down to 500 - 550 rpm. I am willing to bet that the ramps are steep on this cam and even if I had those specs ground onto a flat tappit cam, it probably wouldn't last long without rollers. And I bet that if I used it in the 305, it would have a choppy idle. What do you think? :confused:

After some thought, maybe that 395 cam could work in the 400 with special after market rollers. At any rate its the most interesting profile I have seen for a long stroke motor in a boat that will not see over 4500 rpm.

The other profiles you have mentioned are very respectable but not a whole lot unlike the 151 cam that I have currantly installed in the 400. The LSA for the 151 is 114 which accounts for the smooth idle. As you probably know, the 151 is the only cam ever used by chevy that is single pattern which , to my knowledge, doesn't mount to a "Hill-O-Beans"

stonebreaker
09-09-2006, 12:02 PM
Bobby,

Putting the roller cam in the engine is worth it. Nevermind the improved performance; the roller lifters cut wear down to almost nothing. When I pulled the 845 cam out of my engine, it had 75,000 miles on it. I gave it to a friend, and he had it spec'd before he put it in his engine. It had no measureable wear, according to the machine shop. He dropped it into his car about 4 years ago, and it's been his daily driver ever since.

On the matter of single pattern vs. dual pattern, the modern GM heads have an exhaust flow of 65 to 70% of the intake flow. I don't know what your 400 heads flow, but you should stick with a dual pattern cam for the 305.

On the matter of the cam for the 305: I would suggest logging in to either the 94-96 impala ss forums or one of the 9c1 forums (9c1 is the factory designation for the caprice police package) and seeing if you can find anyone with a stock 94-96 impala or caprice LT1 cam for sale. You should be able to pick one up for about $50 or so. You might find one on ebay, too. It's very similar to the 395 cam: 192/196 duration, 111 LSA, and 5 deg of advance. The impala had a 0-60 time of 6.7 seconds stock, but with a free-flowing exhaust, such as you'd have on a boat, the 0-60 time dropped down to about 6.2 seconds. Max torque with this cam occurs at about 3000 rpm, with peak horsepower occurring at 4800 rpm. This was with an LT1 intake, which has even shorter runners than a single plane. If the 305 has the usual dual plane intake on it, you should see torque and horsepower peaks at about the same rpm as occurs on the LT1.

Good luck with the build.

marshmat
09-09-2006, 01:38 PM
I second Stonebreaker's advice on the roller cam. Anything you can do to cut down on wear is good. Odds are you'll run the boat engine longer and harder than it would typically be expected to do in a car, and anything to reduce friction and wear will really help its longevity.
Some people don't mind the choppy idle as they prefer to run full-out.... in most cases though, I think it pays to do a good job with the build and get a motor that runs nice through the entire range.

gonzo
09-09-2006, 07:06 PM
If you use roller lifters, you must use a roller cam which is hardened. A cam for flat lifters won't last.

bobby4244
09-10-2006, 04:11 AM
Stonebreaker, both the 305 & the 400 use cast iron dual plane intakes. The 305 uses a Rochester 2v and the 400 has a Holly 650 cfm 4v

The heads on the 400 came off the OEM 307 (1973) casting # 3973487X
The heads on the 305 are the small chamber 305HO heads

both engines have flat tops

As far as breathing , on the exhause side, both exhaust through the outdrive and below the water line. I kinda thought this would be restrictive and not promote free breathing. But, then again, maybe the water passing by the exhaust creates a vacumn efect and sucks the exhaust out. Or maybe this is just wishfull thinking.

At any rate, full speed rpm on both boats should be 4000 -4500 rpm if everything is right on.

These are boats and based on WOT of about 4300RPM, am I looking for torque of horse power? In other words, I want to put more pitch on my prop,which will produce more speed and will also put more load on the engine. If I do this now, the RPM's will drop and the boat actually goes slower because the motor doesn't make enough power to keep the rpm's at around 4300

Think of it this way, You have a car that has a RPM limiter set at 4300RPM.
Top speed in high gear is 80 mph at 4300 rpm. You want to make this car go 90 at the same 4300 rpm so you put higher rear end gears in. Now you find that the car actually slowed down and the rpm also dropped because the engine doesn't make enough power. You beleave the problem is the cam profile. Would you install a cam that makes more torque or more HP? Remember, 4300rpm is the limit or the transmission will blow. Based on the above whats your suggestion? My thought is the 395 cam. But, what do I know? :?:

bobby4244
09-10-2006, 04:19 AM
I second Stonebreaker's advice on the roller cam. Anything you can do to cut down on wear is good. Odds are you'll run the boat engine longer and harder than it would typically be expected to do in a car, and anything to reduce friction and wear will really help its longevity.
Some people don't mind the choppy idle as they prefer to run full-out.... in most cases though, I think it pays to do a good job with the build and get a motor that runs nice through the entire range.


I agree on the benifits of a roller cam versis a flat tappet. Read my last post, this is the real issue. AND, I absolutely have to have a smooth idle at about 500 - 550 rpm. This is an older electric shift I/O and a rough idle or a high idle will end up blowing the lower unit on the outdrive:(

bobby4244
09-10-2006, 04:26 AM
If you use roller lifters, you must use a roller cam which is hardened. A cam for flat lifters won't last.


Interesting, I know what the books say but, you would think that a roller lifter would work on a regular cam. HARDENED STEEL FOR ROLLERS :idea:

stonebreaker
09-10-2006, 12:56 PM
Interesting, I know what the books say but, you would think that a roller lifter would work on a regular cam. HARDENED STEEL FOR ROLLERS :idea:
Bobby,

The different designs of the lifters, roller and flat, really alters the profiles of similar flat tappet and roller cams. I suppose a pure racer might be willing to experiment with roller lifters on a flat tappet cam or vice versa, but it's not a good idea for a daily driver. Here's a good basic article on flat tappets vs roller cams, both the good and bad points. The bad points, from the magazine's point of view, consist mainly of the cost of roller parts.

http://www.chevyhiperformance.com/techarticles/95258_hydraulic_roller_cams/

bobby4244
09-10-2006, 01:59 PM
Greetings Stonebreaker,

Read the article, interesting to say the least. But I never had a doupt that the roller cam would be better. Problem is, I am dealing with a SBC 400 that is not machined for rollers. And I don't want to spend big $$$$$ for special rollers or machining.

Some guy on EBAY is selling a book for 20.00 that tells how this can be done on older blocks for cheap. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=200024750367&ssPageName=ADME:B:EF:US:11

Take a look, what do you think?

Personally, I knida think that the 395 cam is gonna be the best way to go for the 400 block and possably for the 305 block as well. What are your thoughts on this ?

bobby4244
09-10-2006, 02:27 PM
Does anyone know what cam this might be? Casting # 1579

stonebreaker
09-11-2006, 02:10 AM
Bobby,

If you want to stick with a flat tappet, give Crane a call and give them your requirements. I would guess that they probably have a cam that will do what you need. If you need a custom cam, they can do that, too. As long as you use lobes from their cam lobe profile catalog, a custom cam is the same price as a stock profile cam. What you do is call Crane and either give them the cam specs you want, or else give them your requirements and let them suggest a cam profile.

I know you weren't happy with the Comp cam you bought previously, but Crane's always done good by us. As a general observation, Crane tends to put a little more advance in their cams than Comp does, which results in more midrange for the Crane cams but at a cost of some top end compared to Comp.

fasteddy
09-12-2006, 01:18 PM
It's been my experience with SBC's that the cam gets less radical as the cube's go up. I swapped a cam from a early z28 301/2 into a 383, and the cammy idle went away, and the idle vac went up. Therefore I'd go with a milder cam in the 305 if you want a smooth idle. I've had good luck with Crane, both with their advice and with their cams, and FWIW, I'd spend the $ on roller just for the longevity. Boat motors run at much higher cruise rpms than car/truck engines, and most of the flat tappet cams I've seen in marine motors had at least one worn lobe.

OutRider
11-10-2006, 07:19 PM
I am replacing my 350 MAG MPI, which has only 100 hours on it but also has a cracked block. WITH Its forged crank and almost 400 ft. lbs of torque at 1500 rpm the ZZ383 looks like a good candidate. In particular, I believe that it has the same cam (GM 846 or Crane 109831) as the old Mercury Racing Scorpion 377. With six more cubic inches than the Scorpion and the same marine cam (see the Crane web site http://www.cranecams.com/index.php?show=browseParts&lvl=2&prt=5&Vehicle_Type=Marine&Cylinders=8&Engine_Make=CHEVROLET&Year=2002&Engine_Size=305-350%20C.I.), there shouldn’t be any water reversion, but… ?

The 350 MAG has Vortec heads and the same block as the ZZ4 and other GM crate motors so my manifolds should bolt right up to the Fastburn heads on the ZZ383. Wouldn’t everything else bolt on as well?

The biggest problem is the computer, which is a Mercury Marine ECM-5550202. I would like to keep it for the SmartCraft features. Some companies say they can remap it but I would rather do it myself. Would it be possible to do that using one of the tools that are available for cars? Alternately, would it be possible to keep the 555 for its SmartCraft features but disable its ignition and fuel outputs so they could be controlled by an automotive ECM?

The MAG 350 throttle body is about 2 7/8” in diameter and looks like it has enough flow capacity, but obviously the wet exhaust will have more back pressure than dry headers. How much power should I expect and do I need bigger fuel injectors, etc.?

It is my intention to set the rev-limiter at 6000 RPM but not run it over 5000 for any length of time. With the right prop the boat should go about 100 mph at 5000 rpm. It will have a fresh water cooling system that is supposed to be able to handle up to 500 hp. Any help would be greatly appreciated.

stonebreaker
11-11-2006, 12:22 AM
I don't see why the computer would be a problem. The Ramjet 350 crate motor uses a marine computer. I'd have to look on the GMPP site to make sure, but I think it's either the MEFI 3 or the MEFI 4. Email Bryan Herter at programmer@pcmforless.com and see what he says - that guy can tune anything. He started on LT1's but has done everything from t-types to c6 vettes. He's pretty reasonable, and doesn't encrypt his tuning, so he can set it up for a good conservative tune to start with, and then you can tweak it to your heart's content.

As far as the 846 cam goes, with that much torque that low, there can't be much reversion going on. That cam's a little choppy in a 350, but I've heard it in several 383's and it's hard to tell there's a hotrod cam in there. I ran its little brother, the 845, in my 350 LT1, and you had to really listen to tell there was a cam in the engine.

Fuel injectors: are you running throttle body injection or mpfi? If mpfi, I'd suggest running either the 36 pounders or the 42 pounders. The 36ers are a little easier to tune, and should be plenty for anything under 6000 rpm (I run 30 pounders to 6400 rpm in my 355 LT1).

FAST FRED
11-11-2006, 06:58 AM
Does anyone have a realistic number for fuel burn of a 350 producing 100hp?

This would assume a 350 set up for low speed and moderatly low power for cruising.

FAST FRED

stonebreaker
11-11-2006, 08:17 AM
Should be around .55 BSFC. .55 x 100 / 6.75 (pounds of fuel per gallon) = about 8 gallons per hour.

OutRider
11-11-2006, 02:06 PM
The computor does not look like a MEFI and it says Motorola on it. There are some old posts on Speedwake that said no one could remap the Motorola ECM used in small block Mercruisers. I assume that by now it is possible but it's still a mystery to me.

Also, does anyone know the size of the injectors in a 2002 350 MAG MPI Bravo or the part number?

FAST FRED
11-11-2006, 02:10 PM
Should be around .55 BSFC. .55 x 100 / 6.75 (pounds of fuel per gallon) = about 8 gallons per hour.

THANKS!!! The gas engine mfg. are really close with this info!

A "good " direct injection diesel would require 5gph , and turboed intercooled and electric injected might get be closer to 4gph.

But of course the diesel fuel is heavier.


FAST FRED

fasteddy
11-17-2006, 12:18 PM
I got real tired of hard to program OEM computers. I started researching this almost 20 years ago when I had an Opel 1900 Sportwagen with a Bosch K-Jetronic. It was only about 10 years ago that I finally found the first systems/companies to do this work. I'm stubborn like that. I now sell and install user programmable efi systems for almost any gasoline/alcohol engine, NA or super-/turbo-charged, with or without nitrous. My all time bang for the buck system is a modified Megasquirt2, followed by an SDS. I've never had luck with chip reprogrammers - too many re-do's to get it right. You have to real time tune with proper sensors - egt, wide band O2 sensor, accurate tach, and monitoring of injector duty cycle and fuel pressure. Boats really need some form of integrating accelerometer, since it's hard to put them on a dyno. I acutally prefer to tune cars the same way, as I do not trust the accuracy or repeatability of a wheel dyno, or the real correlation of the results to real world results. Boats tune a LOT different than cars. Unless you have a clutch in there (bet you don't), you MUST have a very low, stable idle, or like to buy outdrives. I tend to think of props as like a torque converter in a car automatic transmission, unfortunately, without a lockup clutch. This analogy fails to match reality as prop rpm increases. I therefore build/tune boat motors with a cam optimized for the customers requested cruise rpm for best overall performance, and I always advise that you buy all the cubic inches you can get to get all the torque you can get on a wide, flat torque curve, to keep the rpms as low as possible. Engine life decreases by the square of the increase in rpms, and even that may be optimistic.

Go-Man
08-08-2007, 11:51 PM
i'm building a 14' catameran hull, ive seen shallow bottom boats running big blocks, so i figured a way to put in a small corolla type engine (100 HP) and figure cooling,
(just have a pump pushing water over a regular car radiator), lubricant, exsaust, and fual. as for stress, its just not going to go that fast. but from the engine to the prop i know knothing about.:?:

CDK
08-09-2007, 05:00 AM
To get rid of the generated heath you need a water cooled exhaust, which, as far as I know, is not available for a Toyota engine.

Corpus Skipper
08-09-2007, 11:37 AM
You can use a "dry stack" exhaust, liberally wrapped with insulation designed for the purpose. Commercial boats have used this type of system for ages. I don't know about splashing water through a radiator tho. You can get "universal" raw water pumps and heat exchangers and plumb them in, or go for a keel cooler since yours won't be a high speed vessel. Keel coolers are very efficient, and require less maintenance than a heat exchanger. Again, commercial boats have used this system forever.

CDK
08-09-2007, 03:02 PM
A dry stack is little more than a theoretical possibility. There is no flexibility, so you'd have to use a chimney or an over the transom exhaust with a heat shield. Both will break off unless the engine is ridigly mounted, so there'll be a lot of noise and vibration.
The little Toyota engine will generate approx. 70 KW at the flywheel and a little over 200 KW of heat thru the exhaust and the cooling system. No problem in the Corrola it was intended for, but unbearable in a slow moving boat. Commercial vessels may use a dry stack, but have a different displacement to power ratio, diesel engines, lots of space and a crew that has learned to live with the discomfort.

Corpus Skipper
08-09-2007, 05:30 PM
Well, there are some small (25' or less) shrimp boats around here with dry stacks on small 6 banger chevys or something like that. It doesn't seem to be too much of a hinderance. And there are flexible stainless exhaust hoses that go between the manifold(s) and the stack(s). These boats aren't any noisier than one with a wet exhaust. They run the stack through the deck, up the back side of the wheelhouse, and maybe 3 feet above the roof. They use big cylindrical mufflers, maybe 3 feet long, and 6 inches in diameter. Some put a cage around the muffler, some wrap it with insulation blankets. All in all, it's an inexpensive, very functional system, without the worries of wet exhaust.

Go-Man
08-09-2007, 07:01 PM
i said somthing like a corolla (SMALL, its a 14' boat:!: ), i had the exhaust figured, I need help from engine to prop!

Go-Man
08-09-2007, 07:02 PM
i said somthing like a corolla (SMALL, its a 14' boat:!: ), i had the exhaust figured, I need help from engine to prop!

marshmat
08-09-2007, 07:41 PM
A 100 hp Corolla engine, even if you detune it to 60-70 hp for continuous running in the boat, will make any 14-footer I know of go like a bat outta hell.
From engine to prop is a relatively simple matter compared to sorting out the engine itself. Take the ratio of the engine's cruise RPM to the desired propeller RPM at cruise, and go down to your local rebuilt/used boat parts yard (every port town has at least one such place, unless you're in the heart of an expensive yacht-strewn megacity). Look for a F/N/R reduction gear of something close to that ratio you calculated. Well built gears last pretty close to forever unless they're really heavily abused (run with no oil, or with too big an engine, etc). The shaft seal, or "stuffing box", is a pretty simple component you can probably get from the same parts yard. You might also be able to get the struts, shafts and thrust bearing (if it's not built into the transmission) pretty cheap if you look hard, but wear items like the cutless bearing will need to be bought new. This is of course assuming you're talking about shaft or V drive; an outdrive leg is a different matter.
A dry stack exhaust should be feasible if you have a convenient place to run the stack. Make sure it has good heat shields around it or you'll be spending an inordinate amount of time in the burn ward of your local medical clinic.
A car radiator will disintegrate in a matter of weeks in saltwater; a year (two at most) in fresh. If you don't want to cool the engine directly with raw seawater, a heat exchanger of some form is needed- either a keel cooler or a counter-flow saltwater/coolant heat exchanger (probably $900 or so if you buy a dedicated marine model, more like $75 if you're good with bending and welding aluminum or stainless steel and have some time to kill).

Corpus Skipper
08-09-2007, 08:40 PM
Thanks Matt, excellent advice. Basically what I was trying to get across.

Go-Man
08-09-2007, 10:43 PM
im 2 1/2 hours from salt water. its too rough for 14'. anyway i dont think i could
get it there

Go-Man
08-09-2007, 10:56 PM
also thats excactly what i needed, marshmat, Thanks!

FAST FRED
08-13-2007, 10:38 PM
"There is no flexibility, so you'd have to use a chimney or an over the transom exhaust with a heat shield. Both will break off unless the engine is ridigly mounted, so there'll be a lot of noise and vibration."

Quite flexible SS exhaust couplers are at many sources , even flexible enough for a soft mounted engine if noise is a concern. As diesels have fairly low exhaust gas temps (compared to gas engines) a muffler and external exhaust can be wrapped with a few layers of asbestos or its "modern " replacement. A lagged exhaust blanket can lower the temps to EZ hands on temps , but is about $100 for every 4 ft.

The usual is to install everything in an insulated box, although if some exhaust is exposed it can warm soup or whatever.

Dry stack and keel cooling is the cheapest all weather all condition exhaust , although depending on muffler selection may (or not) be the quietest.

FF

marshmat
08-13-2007, 11:43 PM
Of course, if you're going to do a custom exhaust anyway, you may as well form a round, level section about 12" across into the exhaust pipe, right where it exits the manifold- clamp yer frying pan on here, add a pickerel and some spices, and presto, you don't have to carry a stove anymore! :D

Frosty
08-14-2007, 02:43 AM
What a good idea. Ive kept fish and chips warm by placing them under the engine compartment of a car ,--but this could make serious self regulated oven.

Perfect for more delicate cooking like fish or warming pies. For a single hander this is a must. Imagine tying up knowing that your chicken and roast potatos was ready.

Err not sure if it would do roast potatos.

davemtnaire
10-13-2007, 11:30 AM
O.K., I have read almost all 15 pages of this thread, lots of differnt opinions.

I recently bought a boat,1988, 19' open bow, family ski/ fish. The bearings SPUN on the second time out.
It has a "Mercruiser" 350 Magnum (Chevy) I have a friend that works at a GM dealer in the parts department, the block casting number is correct for the year and matches a standard 350 that may or may not have a four bolt main. He can get me a NEW long block, 290 HP 4 Bolt, Stainless head gaskets, brass freeze plugs (all standard), for $1900.
Is there a reason this wont work? Is the cam gonna be a problem? Should I change it? I will not operate this at WOT for long periods as my wife doesn't like goin over 30 mph and it did 50 at 4800 rpm before it blew.

gonzo
10-13-2007, 01:27 PM
He should be able to match the cam. The oil pump should be a low pressure high volume type. The reason for the pump is that the engine will run at higher RPM than a car's for extended periods.

CDK
10-13-2007, 03:09 PM
Only $1900, that's a bargain. The engine will make less than 3000 rpm for 30 mph so it will feel quite happy in your boat. But I've never heard of stainless steel valves. Valves must absorb lots of heat and transfer that to the seats when they are closed, something ss cannot do. But maybe it is just a misunderstanding: the valves may be tungsten or titanium coated.

JustinVero
10-21-2007, 12:24 PM
Hey everybody, just read this whole thread, wow! I'm currently building a 33' deep v runabout boat, and I am planning on running two Nissan VH45DE engines (they come in Infiniti Q45's, a 4.5L V8). I want to run a closed cooling system with a heat exchanger, and this is where my questions start. Does anyone have some link or more info on construcing my own heat exchanger for the cooling system? The other question I have is how do I go about sourcing some sort of transmissions to use with these motors? I would like to usestern drives. I have realtime tuning software and was planning on running the existing individual coilpacks in each cylinder (no distributor). I they should see about 400hp (not shaft hp, more around 300 shaft hp), but they can be run all the way up to about 1000hp each (again not 1000 shaft hp) with twin turbos. Would I need to get anything else besides a marine alternator and starter of some sort? Any finally, I am new to the marine thing, I have 2 nissan race cars, and I am very familiar with all aspects of building and tuning the nissan engines which is why i plan on running them. My last question is this: both engines rotate the same way. On a marine dual installation one prop needs to have counter rotation, right? If so, how would I go about making the scond prop rotate the opposite direction? Is there another type transmission that would reverse the prop rotation? Sorry for the long post and if my questions are silly. Thanks in advance for any help!

CDK
10-21-2007, 01:43 PM
Let's do the easy question first. To have one prop counter rotating you'll need one sterndrive that does that. Or if you will use Merc. Bravo 3's, you can simply put one in reverse all the time (the gear ratio must be identical in both directions).
Engine cooling is a different matter. Can you get water jacketed exhaust manifolds for the Nissans? If you can, but they have no integrated heat exchangers, you can buy std types from Mesamarine. Making them yourself is not impossible but you need some custom made rubber parts that isolate the raw water tubes from the casing and allow expansion. Such parts are available at replacement items for commercially available heat exchangers from Bowman.

JustinVero
10-21-2007, 01:58 PM
Let's do the easy question first. To have one prop counter rotating you'll need one sterndrive that does that. Or if you will use Merc. Bravo 3's, you can simply put one in reverse all the time (the gear ratio must be identical in both directions).
Engine cooling is a different matter. Can you get water jacketed exhaust manifolds for the Nissans? If you can, but they have no integrated heat exchangers, you can buy std types from Mesamarine. Making them yourself is not impossible but you need some custom made rubber parts that isolate the raw water tubes from the casing and allow expansion. Such parts are available at replacement items for commercially available heat exchangers from Bowman.

I have not seen any exhaust manifolds that are water jacketed as of yet. Would it suffice to extensively wrap the exhaust manifolds with exhaust wrap, as I do on my race car, or will that not be enough? If not, I can probably fabricate some water jacketed exh mani's for the engine if I see what others look like. What about on the Bravo 2 drives? I just need to make sure that one of the drives is counter rotation? I have found a used set of the Bravo 2's that I'm considering thats why I ask. Thanks for the help!

marshmat
10-21-2007, 06:39 PM
Justin,
In a sterndrive setup, all shift and gear reduction functions are generally housed within the sterndrive unit. In rare cases a 2-speed transmission is placed between engine and drive to improve time-to-plane, but the usual setup is a direct connection from engine to sterndrive. In the case of the counter-rotating drive, this too is included in the drive unit (it is often accomplished by replacing the standard lower unit gearset and dog/cone clutch with one that moves in the opposite direction to normal). To check, just try to turn the shaft a quarter-turn with the gearset in forward (note that the drive is removed from the engine at this point!) and watch what happens.
The Bravo 2 is almost always used in counter-rotating pairs, they are designed for heavy cruisers with large-diameter props, and would have a strong tendency for asymmetrical, torquey steering if used as a single installation. If you're thinking of a fast boat that isn't wide fat and heavy, a pair of Bravo 1's would be the most common choice.

JustinVero
10-21-2007, 09:26 PM
Justin,
In a sterndrive setup, all shift and gear reduction functions are generally housed within the sterndrive unit. In rare cases a 2-speed transmission is placed between engine and drive to improve time-to-plane, but the usual setup is a direct connection from engine to sterndrive. In the case of the counter-rotating drive, this too is included in the drive unit (it is often accomplished by replacing the standard lower unit gearset and dog/cone clutch with one that moves in the opposite direction to normal). To check, just try to turn the shaft a quarter-turn with the gearset in forward (note that the drive is removed from the engine at this point!) and watch what happens.
The Bravo 2 is almost always used in counter-rotating pairs, they are designed for heavy cruisers with large-diameter props, and would have a strong tendency for asymmetrical, torquey steering if used as a single installation. If you're thinking of a fast boat that isn't wide fat and heavy, a pair of Bravo 1's would be the most common choice.



Thanks for the reply! So would the Bravo 1 be a better choice for me then? Like I said before, the boat I am building is 33' with an 8' beam. I would like it to go pretty fast, I am shooting between 50-75mph under ideal conditions. This may require that I make more than the 400 hp out of each engine, in which case I can modify them, but my concern is will the sterndrive be able to handle a power increase over the 400hp (300 shaft hp)? I should elaborate on how I intend to use the boat. I will primarily be just taking it out on the weekends for pleasure...just crusing the beaches, coastline, the st. lucie river here, etc, moderate use. I would eventually like to make the trip down the coast from here (Vero beach) to about west palm beach (actually a little further south), which is approx 50 miles south and then heading over to the bahamas, which is about another 60 miles or so. Which stern drive unit would be the best option for what I would like to do? Bravo 1? maybe the bravo 2? I just want to be able to upgrade my power if needed without worry of damaging the stern drive. I assume that the sterndrive will connect to the flywheel in some manner? I also am curious as to what gear ratio stern drives to use, along with props, but I assume I need my engine data to know what rpm I want to cruise at, right? Thanks for all the help, and sorry for all the newbie questions!

JustinVero
10-21-2007, 09:41 PM
I should also note that I am not planning on running 50-75mph all the way over to the bahamas. I would like to cruise around 30-50mph

marshmat
10-21-2007, 09:50 PM
If you're interested in Merc drives, they publish most of their specs at
http://northamerica.mercurymarine.com/engines/inboards/sterndrives/
Alpha is for smaller boats, less than 300 hp.
B1 is the all-rounder for fast boats, they warranty some of the new ones to 600 hp now.
B2 is a specialized drive for heavy, twin-engine cruisers that need large-diameter props, max 450 hp.
B3 is the American answer to Volvo Penta's Duoprop, counter-rotating props and up to 525 hp.
Compare to the VP range at http://www.volvo.com/volvopenta/global/en-gb/marineengines/drives/
Important note with all sterndrives- note that no matter what brand/model you choose, the driveshaft couplings and bearings will be quickly destroyed if you run the engine while the drive is tilted up in trailering position. You can only run the engine while the drive is within its normal running-trim and shallow-water-trim angles.

JustinVero
10-21-2007, 09:57 PM
Thanks again. I actually have no preference in which drive I use, just want the one thats the best all-around and dependable, which seems it may be a merc bravo1

CDK
10-22-2007, 01:30 PM
A quick survey on the Internet shows no sign of water cooled Nissan exhausts, so most probably you are about to enter uncharted territory. That challenges some people and scares the hell out of others.
As you mentioned lots of horses (= lots of heat) from compact engines, water cooled manifolds are the only solution. I once read the diary of a guy who was determined to build his own submarine with a rowboat's budget. He tried to sand cast some parts, but the last I saw was the unfinished hull sitting in his garden as entertainment for his children. Casting the manifolds would be an option, but certainly not a do-it-yourself project.
An alternative would be to compare what is on the market with what you need. If there is a model from Glenwood or Bowman that comes close, you could make adapter tubes with flanges from mild steel.

Another item that will not be available of the shelve is a bell housing that fits the Merc sterndrive.If the Nissans have a flat flange with the flywheel recessed, you can make an adapter plate, otherwise you'll have to construct a complete bell housing with two lugs to match the holes in the transom housing engine support. An engine coupler, available from Mercruiser or Sierra Marine, must be machined to match your flywheel, but that is quite simple compared to the manifolds and bell housings.

I just finished converting 2 VW turbo diesels. There were water cooled exhausts available, albeit for a smaller engine without turbo charger, so I had to make dozens of parts myself, both mechanical and plumbing. I hope to start them for the first time at the end of this week when the last electrical parts arrive. It kept me busy every day for about 12 weeks now.....

JustinVero
10-22-2007, 10:27 PM
I have seen the same engine I intend to use in an open-air ski/drag boat in New Zealand. If I make some sort of fresh air circuation system for the engine compartment and wrap the exhausts well, wonder if that would be enough? Here is a link to a video of the boat on youtube. I believe in that small boat he goes around 120mph, with a twin turbo, 1,000 hp engine.

http://youtube.com/watch?v=9nsVNpkk_D8

CDK
03-01-2009, 04:24 AM
"The mechanic said it could be a variety of things and omc is **** and he wouldnt recommend fixing it....."

He's right, although I wouldn't put it so crudely. The 4-in line is a GM product, designed before 1950, with very little success in passenger cars. Its main applications are AC generators, compressors and small stern drives. OMC's contribution is only a paint job.

To transplant the Nissan you need to do the following jobs:

-Fit the OMC bell housing to the Nissan or make a new one with the proper geometry (shaft height, distance etc).
-Attach the OMC engine coupler to the Nissan flywheel.
-Find a water cooled exhaust manifold that fits the Nissan or make an adapter to use the existing manifold if that is in good shape.
-Construct an engine support for the front of the engine in the same style as on the OMC, or two separate supports if the Searay's bottom offers that choice.
-Make a linkage arrangement for the gear shift cables on top of the valve cover, with a microswitch that shortens the ignition during gear shift.

First concentrate on the exhaust issue. If you can solve that, the rest is easy.

rexxer
03-01-2009, 04:31 AM
Thank you CDK. That was the first thing that has made sense to me since buying this boat :)

gonzo
03-01-2009, 07:39 PM
The 3.0 Chevy was very succesful in cars as tens of thousands of taxis can prove. The upside of it is that since they made millions of them, parts are available and relatively cheap. By the time you marinize the other engine it will cost you more in parts and time than rebuilding what you got. Also, it is such a common engine that the machine shop will be familiar with it

rasorinc
03-01-2009, 08:00 PM
Wasn't this posted originally under another heading? Pleas do not double post.

Machineman
07-01-2010, 07:23 AM
I don't know how it is where you live. Here, marine engines are fuel injected and have the latest technology in electronics. If you were to use an automotive fuel injected, computer controled engine, the changes would be beyond your capabilities. For example, how do you reprogram the computer to account for a marine engine not having an oxigen sensor. It cost more to marinize an automotive engine than starting with a marine one.

There are many ways around the problems that are constantly claimed to be too difficult to solve. Basically,
1. Change the obvious, fuel pump and starter etc for safety.
2. Do not use raw water, just run a heat exchanger and do not change the engine at all. No gaskets or anodes or ANY of that rubbish. Leave the engine alone in it's own cooling fluid. It will run at normal temps and no "shock from raw water temps" it's all rubbish and fear mongering fuel "boiling" blah blah blah.
3. Biggest issue is a set of custom exhaust manifolds, that can use an o2 sensor, get em made or make them yourself but save an absolute BOMB of money to power your boat compared to ridiculous marine dealers. They rely on people complying to their way.
4. Overpower your boat, no need to run at 5000rpm+ to plane, if so you have the wrong gearing/prop. You will read pages of crap here about why it won't work, BUT, if done well, it works better than any marine dealer wants you to know.
So, be safe, cool your driveline well and set up good monitoring for heat. Ventilate engine bay and fuel storage bay (all things that "marinized" set up's require anyway.)

I personally think that threads like this fail to understand the point, people would not ask for advice if they had enough $$$ to buy great new marine gear. I have had way more satisfaction in boating by using modern efi engines to power home built hulls with surprising reliability, way more fun than when I got "violated" by a sea Ray salesman when purchasing a 270 sun deck for $80aud.... I have felt like a fool ever since.
Be safe and marinize anything you want, more fun and cheaper than your local rip off marine merchant.

Machineman
07-01-2010, 08:13 AM
The marine version of the engine has an electric system that is explosion proof. The fuel injection is self contained and legal for marine use. The cylinder temperatures of an engine in marine use are much higher than in a car, even a race car. It is the equivalent of running a vehicle with a full load at WOT uphill for hours on end. Boats don't reach cruising speed and then require less power to maintain it. A larger gap is necessary for extra thermal expansion. It is not bogus. Also, Mercruiser engines have Vortec cast iron heads. Aluminum heads wouldn't last long in salt water. I sell new 5.7 engines for $5495.00 complete. The link to the engines you sell is advertising a base engine. The comparison is really bogus.

Gonzo, have you read the above info, it's a fact, they are the same thing with a sparkless electrical system which is in itself debatable in need. When is the last time a boat exploded and was not leaking LPG, engine fuel explosion? When?

Save the self promotion for work.

CDK
07-01-2010, 11:35 AM
3. Biggest issue is a set of custom exhaust manifolds, that can use an o2 sensor, get em made or make them yourself but save an absolute BOMB of money to power your boat compared to ridiculous marine dealers. They rely on people complying to their way.


This thread is sleeping for a few months already, but I like your attitude.
Solving the O2 issue is even easier: leave the sensor terminal on the MMU open and it will immediately substitute a fixed value for the sensor output. It also switches the malfunction warning light on, which you can ignore.

Machineman
07-01-2010, 09:34 PM
Thanks, I have always tried to alter the function of the engines as little as possible but may have wasted a fair slab of time in unnecessary inclusions.
This will make my next set of manifolds even easier and I'll disconnect the warning light, or like you said, just ignore it.
Thanks for the tip.

View Full Version : Auto engine marinization