Auto engine marinization

[tom kane]

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]

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]

Originally Posted by gonzo

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]

Marine engines are not "de-sophisticated". Try working on an 8.1 without a computer or proper training.

[tom kane]

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]

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]

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]

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]

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]

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]

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]

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.

[tom kane]

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.

I am interested in Marinizing 2 Nissan TD-42 Diesel Engines which I would like to fit in a Boat,

[gonzo]

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.