marine vs. automotive - Vortec [Archive]

Beech2000

01-01-2007, 10:06 AM

I have a 5.0 vortec installed in my 98 sea ray and would like to rebuild a 1999 5.7 removed from 1 ton work truck I was given if possible.:idea:

I understand the intake, carb, and exhaust being marine application as well as the electriacal components but I read Marine heads for vortec, I read marine 5.7 liters. What gives?:confused:

What differances can I expect from the basic Chevy long Block? (i.e. Oil Pan, front timing cover, cylinder heads etc...).:cool:

Great forum and I look forward to responce.

stonebreaker

01-01-2007, 06:47 PM

There's not really that much difference in the long blocks. It's mainly the accessories and the fuel system that are different, and if you're re-using them, you'll be OK. As far as the oil pan, does your original engine have a one piece or two piece rear seal? If it's a 98, I would assume it's a one piece, like the truck engine, so you should be able to reuse your marine oil pan.

Judging by GM's power curves, the boat cams are somewhat in the middle between car and truck cams, in terms of torque curve and peak horsepower. The car cams make more horsepower, the truck cams make more torque.

GM's main weakness is their valve springs. If I were in your place, I'd use the Comp Cams beehive springs, pn 26918, and then go with either a Crane marine cam, p/n 109811, or else the GM cam 14097395. The GM cam is used in both the high torque 383 engine and also the Ramjet 350, and is very similar to my stock impala cam. You can go here (http://www.gmperformanceparts.com/_res/pdf/gm_performance_parts_catalog_2006.pdf) and see the torque curve on the Ramjet 350 crate engine page.

Beech2000

01-02-2007, 06:15 AM

Thanks for the reply Stone,

I took a look at the main seal and verified to be one piece on both engines.

So the truck block and heads are not specific to Marine application?

The parts guy at my local marina say's the cylinder walls are thicker, the internal water passages are differant and as you mentioned the cam is marine.

My goal for this project is following:
1) More bottom end torque using same 19 pitch prop for pulling 2 skiers/slalom.
2) More upper end speed without changeing prop. Currently boat speed with 4 people is around 45mph at W.O.T. 4200RPM. (Would like 50 or better at W.O.T.)

I realize changing to a ski boat sounds logical but I don't like the way true direct drive / Flat bottom ski boats ride or look.

Plus I feel I could build the truck engine for very low cost due to friend at machine shop who will boil block, true deck, bore cylinders .010" to .030" and rebuild heads at no cost. That is of course with me to supply the parts.

The biggest problem with all of this is the fact that the current 305 engine in boat is basic 2brl carb. So I have been shopping E-Bay and net for Vortec 4brl intake and carb for Mercruiser. As of now I have found lots of Pre-vortec manifolds only. That is with out spending 300 or more just for intake.

I am bugeting around 1,500-2K total for rebuild, carb and intake combined.

That is of course if 350 engine passes NDT and is not cracked. I know the history of these engines and all get replaced with new crate engines at 100K. I cut the 350 oil filter open and paper was clean as a whistle. I could almost get by running it as is but want a little more HP out of it as well and up to the challenge.

So I shouldn't have any bolt on or integrity issues?

Kevin

stonebreaker

01-02-2007, 10:35 AM

Yeah, I hear a lot of that too - that marine engines are some sort of magical beasts and no automotive engine could possibly stand up to the strain :rolleyes:

Yet, if you go to gmpowertrain.com and look at the marine engines, they use cast pistons, cast cranks and cast 2-bolt main caps. They even still use forged rods, despite the modern powdered metal rods being both stronger and better balanced.

The real difference between marine and automotive isn't in the strength of the parts. The real difference is corrosion protection and some marine safety issues. For example, the marine engine uses head gaskets with stainless steel inserts, and brass freeze plugs. My LT1 engine has brass freeze plugs in it, so you may not have to change the plugs in your block. As you mentioned, the accessories and the carb are specialized for marine use, but the block and heads are just the standard block and heads.

On the prop issue, it sounds to me like you might be a little overpropped as it is - 4200 seems a little low for max rpm. GM lists peak hp for both the 305 and 350 marine engines at about 4800 rpm. So if you build the engine with 5000-5500 as the target rpm, you should see 50 mph easily. 5500 rpm is well within the stock bottom end's capability, so where I'd focus my efforts would be the valve train. As I mentioned before, either the Crane or the GM cams would work well in this application, both peak at 5200 on a 350, although I favor the GM cam. Spend the extra bucks for a good set of springs (I like the Comp behives), and make sure your pushrod length is correct for the cam you eventually go with. If you can afford roller rockers, so much the better. Since you mentioned you'd be machining the block, make sure you fit the timing chain correctly so there's no slack in it. You know, details...

Beech2000

01-02-2007, 07:41 PM

Stone,

I can get 4800 WOT by my self in boat but not with 4 adults. Should I be able to?

I did go on GM's many web sites regarding marine applications and the link you sent me to. I aggree now and very pleased that this will work.

The engine has double roller timing chain, roller lifters as well as 4bolt main caps. Wow this engine is very nice!!. Lot differant than 307 in my high school nova.

I am half tempted to just change do valve job with crane cam springs install GM marine cam and lifters and run it. I think I still see the hone marks on cylinder walls. Oh. Do marine application SB's use Stainless valves?

Jango

01-02-2007, 08:48 PM

4800 RPM with driver only is exactly right. Your prop is correct.

Summit Racing sells an Edelbrock Marine 4 Brl for about the same cost as the Auto version. I use the 750 cfm unit on my boat - very good carb.

I believe S.S. valves are used on GM motors although not sure. By choice my marine Ford has S.S. valves.

If at all posible, use the Roller lifter/cam - an automatic 50 hp and 50 ft - lb even with the same duration/lift.

Good luck, sounds like you're on the right track.

Jango

Beech2000

01-02-2007, 10:38 PM

I guess corrosion and higer tolerance to heat are the main advantages of the Stainless valve as opposed to the factory steel right? So its an integrity upgrade that is sounding very expensive...

Gee's Sky is the limit to the high quality parts availiabllity.

I will check into it though.

The truck engine appears to already have roller tappets. can roller tappets be reused? I know flat tappets are not reusable but on the other hand I don't want to jepardise quaility and integrity just to save a buck.

Thanks for the reply Jando and Stone. You have realy helped me alot.

stonebreaker

01-02-2007, 11:53 PM

Agree with Jango, your prop seems correct if you can hit 4800 rpm with the boat light. Except now, you should be able to hit it with the boat full.

As far as the cams go, I couldn't find the actual specs on the current roller cam for the 5.7; however, I DID find the part number for the flat tappet cam and lifter kit, which is 12353918:

12353918 - Camshaft Kits

All "Marine" and off-road small-block Chevrolet V8. Compression ratio 8.75 - 10.5 to 1, 2600 - 3000 cruise rpm, basic rpm range 2000 - 4500 rpm, 6500 rpm attainable with proper valve springs and lifters.
Technical Notes: These are hydraulic flat tappet camshaft kits. The duration at .050 lift (intake/exhaust) is 214/224 degrees, and the valve lift is .442"/.465". Lobe centerline is 112. This camshaft kit is designed and manufactured by Crane Cam Cov.®. It contains one camshaft and 16 tappets.

This is extremely interesting, because GM sells a roller version of that exact cam, p/n 12370845. I ran that cam in my car for three years, and it is indeed capable of revving to 6500 rpm with the correct springs. It is an all-around bad ass cam. I have run a best of 12.6 at 108 mph with that cam in my 96 impala, at a race weight of 4400 lbs, and still get 22 mpg on the highway.

Having said that, I'd still opt for the ramjet 350 cam, as the 845 cam design is about 20 years old and isn't optimized for the vortec heads; the ramjet cam is. Hell, for all I know, the new marine cam may BE the ramjet cam, I won't know until I can find the specs. However, I suspect the current marine cam is still the older 12370845 cam, or 845 cam for short, for this reason: I went to the Crane website (all GM cams are manufactured by Crane) and looked up marine cams. Crane sells the GM 845 cam as part number 109821 in automotive applications; however, when you look up cams for a 98 marine engine, you get p/n's 109811 and 109831. P/n 109821 is strangely absent. This seeming oversight is explained, however, if Crane 821/GM 845 is still the current marine cam and Crane can't sell it in competition with GM.

Crane sells cams in families, with the exhaust lobe from the smaller cam becoming the intake lobe for the next larger cam. You can see this if you go to the http://www.gmperformanceparts.com/ website and look at cams 12370845, 846, and 847.

Let me know if I'm losing you.

stonebreaker

01-02-2007, 11:58 PM

PS - the marine engines don't use stainless valves. Go back and look at the gmpowertrain site - while they are very careful to point out the stainless insert head gaskets, fuel rails, and injector tips, nowhere do they mention stainless valves.

Roller tappets can be reused. The stock roller tappets are good to about 6500 rpms.

Beech2000

01-03-2007, 09:13 AM

stonebreaker

01-03-2007, 07:30 PM

Wow,

Definetly lots of info. You sure know your cams.

So. would you recommend the reuse of the roller lifters with the competion cams beehive springs and the GM RamJet 350 cam?

I fear noisy valve train should the truck lifters not pump up. Your thoughts?

Yeah, I think the ramjet cam is the better cam for your situation, but only a little better than the 845. It makes a little more torque in the midrange, a little less horsepower up top. If you usually run with a full load, the ramjet is going to be a better choice, although the difference between the two cams is going to be less than 5% at any given rpm. My gut feeling is that the ramjet is going to be a little more fuel efficient, but I really don't have any data to back that up.

I've run the stock lifters out to 6500 with no problems. However, you'll want to examine both the cam and the lifters before re-using them. Look for any pitting or cracks on the rollers and the cam lobes. If you see ANYTHING suspicious, dump them and get a new set. Every time I swap cams, I like to go over everything both by feel and with a magnifying glass. Here's a pic of a cam that was about to cost me a lot of money if I hadn't been planning on swapping it out anyway. Turns out I had a broken spring that was allowing the lifter to bounce across the top of the lobe. I never heard anything - just got lucky I decided to swap that cam when I did.

I caught the crack just right in the second pic. That cam was made by Erson, btw, and is not a GM cam.

Beech2000

01-03-2007, 08:37 PM

stonebreaker

01-03-2007, 09:09 PM

Stone,

Do you know what the lobe centerline angle is on the RJ Cam?

I fear anything less than 110 might jeopardize idle and acceleration from low speed high load.

Hey Stone, in referance to the quote from GM Performance brochure I read the following,

Quote:"The Ram Jet 350 makes it easy to have electronic fuel injection on any 1976 and older vehicle originally equipped with a
carburetor. The secret is the industry leading MEFI 4 controller. This new controller fits in the palm of your hand and was
originally developed by GM Powertrain engineers for marine applications."

Wonder what GM sells this set up for? How could I find cost out or does it only come with crate engine only>

The LSA on the ramjet cam is 109 degrees, vs. the 845's 112, but because its duration is smaller, it actually has less overlap than the 845, so it will idle smoother than the 845, although the 845 already idles pretty smooth - you can't hear the lope unless you know what to listen for. The stock cam on my 96 impala - my STOCK, FACTORY cam, has a 111 deg LSA. This gives it huge torque in the midrange, and is another reason I like the ramjet cam - my stock cam is basically the ramjet's little brother.

ON the mefi controller, here you go: http://www.sdpc2000.com/search.asp?searchterm=mefi&doquery=1

Beech2000

01-03-2007, 09:45 PM

Not seen or heard about after market Port fuel injection out side of OEM. Mercrusier included. I Need to toss this idea altogether as safety and durablilty needs to be first concerning marine toys.

Just in the preliminary stage of gathering info for the best bang for the buck. Guess I'll continue my search of great deal on vortec cast 4bbl manifold and carb.

Thanks for the research on the MFI set up.

I like the sound of the RJ Cam though. I just fear overcaming like I did once upon a time to a Ram Air 400 years ago. this is a family boat and not off shore racer.

Looking for good balance. A friend of ours bought one of the new Baja's with merc 5.7 FI that has this balance but with a 50K price tag. Ouch!

This lit up another light bulb in my head. Wonder if any detail specs are publically published on High performance merc's.

If so I wonder if the same specs on the RJ Cam you mention and speak so highly of might not match similure profiles of that in the marine GM engines.

I much appreciate your input and quick responce and who knows, maybe the back side of this project will prove to be benifical to all of us weekend water racers.

stonebreaker

01-03-2007, 10:54 PM

A couple of suggestions. Would that mefi controller be cheaper than a carb and manifold? YOu could use it on the stock truck manifold and throttle body.

Did you happen to get the wiring harness and computer off the truck along with the engine? If not, maybe price one at a junque yard. Then have the stock computer reprogrammed for the boat. These guys (http://www.pcmforless.com/) can reprogram your stock computer for not too much. They can also tell you what computers would work best on your engine, so you don't have to try and track down just your model and year. I would imagine any Gen I or Gen II v8 computer could be made to work. Then you can take a wiring harness and strip out the fuel injection part and chuck the rest.

Beech2000

01-04-2007, 09:01 PM

Nope,

My friend just gets the long block to keep. The trucks get new long blocks every 8 years. This one has 217,000 miles on it which is more than I originally thought. I just received the service records on it. They retained the fuel injection system for use on the new long blocks. So knowing this I am forced to go the whole way and rebuild. In regards to the MEFI I thought I would have to purchase each piece which would total over 1,500. Plus again since I am running this for marine I am going to stay away from aluminum. Sure wish aluminum would work in marine for weight.

Oh speaking of weigh, I assume there will be little difference in weight between the 305 and the 350 right??? Please say yes LOL..

With dual battery set up and heavy V8; I seem to always ask my Daughters to sit up front. The V6 powered 190BR's run about the same speed as mine and is really the better choice of engine for my boat. This being said, I just like the V8's better and OK with the extra weight.Plus my boat has captains choice exhause which is a hit at coctail coves.

I am going to pickle, preserve and dry store the 305 at my office as a back up should the 5.7 not hold up to the bruttle punishment marine engines are subjected to.

I think I might have found a complete marine 4bbl manifold and Q jet carb removed from late model cabin crusier locally. I hope its late enough to be vortec. I am told the crusier is a 1997 which scares me because marine engines seem to be a couple of years behind detroit. I guess this is due to manufactureing time of vessel combined with mercrusers limeted orders and manufacturing time following new development or change.

gonzo

01-04-2007, 09:11 PM

The exhaust valves are SS.

Beech2000

01-04-2007, 09:32 PM

Gonzo,

The exhaust valves are Stainless Steel on the 5.7 liter vortec truck application engines?

gonzo

01-05-2007, 09:46 AM

AI'm not sure. They are on the marine application ones. The exhaust on wet exhaust engines gets a lot of humidity after the engines stops.

stonebreaker

01-05-2007, 04:15 PM

You might try some junk yards to find the parts you need - fuel rail, injectors, fuel regulator, stuff like that. I went to the first place that popped up on Google - http://www.partshotlines.com and found several "fuel injection assemblies" for around $100-150. You'd still need to find an intake manifold and probably a throttle body, but GM sensors are cheap and the junque yard and are usually still good. You'll have to weight the cost in time to go the fuel injected route vs. the simplicity of the carb solution. Just be aware that the fuel injection is most likely going to be 50% more fuel efficient or better, so it will be the cheaper solution over the long run (but a steeper learning curve in the short term).

gonzo

01-05-2007, 04:23 PM

Beech2000

01-05-2007, 06:52 PM

Thanks Gonzo

Any other differances in Marine vs. Truck version long block that you can think of?

stonebreaker

01-05-2007, 08:14 PM

Automotive fuel injection systems are different than the marine versions. They are closed with no return line. The injectors are also calibrated to run at a different pressure. Check other threads where all that is discussed. I think you may get 15% better fuel economy at best. Stonebreaker: was that a typo?

No, just me forgetting that marine fuel injection systems have no closed loop feedback (no O2 sensors). The O2 sensors are the cat's ass when it comes to part throttle fuel economy.

On the fuel return line, the newer (LS-based) automotive systems don't use a return line anymore. Don't know about that truck in particular, but it's not hard at all to convert to a dead head system, if it's necessary for safety regs. All you need is a couple of saginaw to AN adapters, some fuel line, and an LS1 - type fuel regulator.

gonzo

01-06-2007, 01:18 AM

So the new automotive type has a low and high pressure pumps and a fuel vapor separator like the marine version?

stonebreaker

01-06-2007, 08:32 AM

So the new automotive type has a low and high pressure pumps and a fuel vapor separator like the marine version?

They use a high pressure pump and then a regulator to adjust the pressure. How do marine fuel vapor separators work? The automotive versions use a charcoal cannister that is vented to the intake manifold.

Beech2000

01-06-2007, 10:35 PM

Check this out

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=002&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=120071636320&rd=1&rd=1

All the parts I need. LOL

Hey Stone, How do you embed the hyper links into the text?

When I insert the hyper link it shows the whole URL. Even in preview.

Anyway, I might put a bid in on it as it has all parts I need for marine FI including computer. That is if final auction price stay's under 2K.

What do you think?

stonebreaker

01-06-2007, 10:45 PM

Looks like a plan to me. You'd have to go over all the stuff, but even though it's more expensive, it's probably less of a time investment than trying to adapt an automotive system to your boat.

As far as embedding the hyperlinks, you have to do it in the 'advanced' window (click 'go advanced'), type the words you want to appear as a link, then highlight them, click the 'insert link' icon (the blue ball over the chain link) and paste the link in the popup. It appears as hypertext in your reply pane, but once you post it shows up correctly.

Beech2000

01-07-2007, 12:11 AM

Hey I happened to run accross a past thread. Deep in the thread I noticed where you and Gonzo share words.

Who won the race?

Looks like you resolved you differances by the several replies in this tread.

Any way. In regards to the water logged engine on E-bay, I only consider this as an option. Still in descision phase and not sure why but I am going through my second childhood and have an itch to build an engine.

My Drag racing day's were 25 years ago. I love the water toy's in my older years. Plus the women on the lake are barely wearing anything and sometimes nothing. I have to look harder to find beautiful girls at Commerce drag strip.

Anyway I appreciate your input on the cams. I've learned much.
I am in the aerospace industry overhauling Pratt & Whitney Gas / Turbine engines for light business aircraft. One model engine we support generates 1400 horse power at 1,900 prop shaft RPM and with oil weight is less than 500 pounds. Bet that would run sweet in my searay ahy? Obviosly this kind of weight vs. horse power comes with high price tag and isn't realistic.

Here is our web site (http://www.atlanticturbines.com) (We'll see if the hyperlink works)

Besides I love the small block chevy.

I will keep an eye on the e-bay engine and if the price stays below 2K, I definetly will consider it.

See ya.

stonebreaker

01-07-2007, 01:10 AM

Gas turbines and boats, eh? You'll definitely like this link: Nye Thermodynamics (http://www.gas-turbines.com/)

Take the time to completely explore this link. He's got some neat projects on there besides the turbine-powered jet boat - including the world's first wood-burning gas turbine, the NT/6.

I'll pretend I didn't read the other part of your post. ;)

Beech2000

01-07-2007, 08:56 AM

I find that I am more interested in staying away from aircraft and related in my spare time if you know what I mean.

Sounds like Gonzo won.

On another note, I had minor issue at end of season last year where my sea ray has become hard to take out of gear. I understand the dog clutch wants to stay engaged unless the engine is momentarily interrupted. So in effort to take care of problem before season starts I decided to scope situation out.

With the stern drive cable disconnected, I can move by hand but not as freely as I would have hoped for. So I removed the drive last night. I will be ordering a new cable. Also I noticed the interrupt switch looks like hell meaning the end of the switch appears missing or melted of sort. Weird. I Will hit the marina for a new one of those as well. I started engine in garage to check operation and it eventually kills engine but not as quickly as I would expect. So using an alligator clip I shorted the input wire to ground and engine immediately quits. Definitely a bad switch.

The only thing I am not sure about is where I can purchase locally the very long 9/16 thin wall socket to get cable housing fitting loose from bell. Anyone have some ideas?

I have a long (But not long enough) craftsmen 1/2 drive 9/16 that becomes flush with nylon not allowing any room for ratchet square drive. I wish I could find a socket locally that has external wrenching feature as this would do the trick. I already hit the snap on truck and nothing. He's an idiot anyway so I didn't bother to look in catalog. Mercruiser must sell one but would have to order.

I would like to be done today as I have to get on plane tonight.

Stone, I will be heading your way for the early part of the week. Where are you in relation to Galesburg, IL?

gonzo

01-08-2007, 12:54 AM

vapor separators in marine use have to be closed. They look like a carburator bowl, with a float that operates a needle valve. When there are vapors in the system, the float goes down and the vacuum from the manifold sucks it in . As the system gets purged of vapors, the float goes up until the needle valve closes. I think a canister would be illegal in a boat.

Dennis T

01-10-2007, 06:19 PM

Beech 2000, could you send me your e-mail please, I got a question for you. Thank you letsgorace@adelphia.net

Beech2000

02-02-2007, 06:02 PM

Who makes the best manual for building the small block chevy for marine use beside mercruiser. (i.e. fits and clearances, ring gaps, torques dimensions etc...)

Mercruiser wants to much money for the oem manual.

stonebreaker

02-02-2007, 06:20 PM

There are lots of engine building books out there. One of the most respected engine authors out there is David Vizard. Here's a link to his smallblock chevy rebuilding book. (http://www.amazon.com/How-Rebuild-Your-Small-Block-Chevy/dp/1557880298/ref=pd_sim_b_4/104-1385946-4879153)

Beech2000

02-02-2007, 06:55 PM

Thanks Stone,

Oh by the way the I chose not to boil the block but did have it FPI'ed and no cracks. I also had the deck(s) cleaned up and had each cylinder nitrogen pressure checked to 4000PSI unheated and found no leaks.

Also the both intake and exhaust valves are steel. Will be replacing exhaust valves with stainless for marine use. any recommendations?

I was shocked to see the factory did install brass freeze plugs.

So far so good..

stonebreaker

02-02-2007, 11:34 PM

I used Manleys in my engine, but Ferrea valves are also really popular with the high performance crowd. Check out Mahle pistons - they're really high tech. They use special low expansion alloy in their forged pistons, and they use special coatings to reduce friction on the skirts.

This guy is a buddy of mine: http://www.ellweinengines.com/ he's a nuclear reactor operator in his day job - the engine building is how he pays for his race car. Most of the stuff for the LT1 will also fit the vortec engines.

Oh yeah - here's his hobby site: http://www.karl-ellwein.org/

Beech2000

02-09-2007, 10:18 PM