GEM930

Hey guys,

I"m new here and I was hoping I could ask a couple quick questions. I've checked the FAQ and past posts, but was hoping for some subjective input on a project I'm considering. I purchased an aluminum racing boat and was going to put a EFI 6.0 Chev. engine in it. This engine is 399 ftlb torque at 4400rpm and 377 HP at 5000 rpm. I have a line on a LS1 (99 Camaro) with low miles and was wondering if this might be a good choice instead. I have an aftermarket ECU (EMS) and some experience using them on Porsche engines, but nothing on Chevy. I can't really spin the jet much over 5000 rpm. What would I need to do the match the 377hp and 399 torque from the engine at 5000 rpm or less? What kind of $ would it cost? Also how much lighter is a LS1 then an iron cast 350? One last question, and probably the most important one: Is the cast on the block and heads the same as a standard 350 ie. - would my 350 bell housing and exhaust manifolds fit on the engine.
Thanks for your time. I hope to hear back soon.


GEM

TransAm00

off the top of my head i would think nice set of heads and a cam the is good on low and mid range. of course exhaust won't be a problem

BADSZ28

iTrader: (39)

The exhaust from a 350 will not fit an LS1. A mild cam with an LS6 intake will give you those numbers easy. Aluminum is 1/3 the wieght of iron. As for the bellhousing I'm not sure, I think they are the same, but they make adapters out there. I would love to see a boat with an LS1 in it. That would be cool. I am a boater and I have seen many set-ups, but never an LS1. I'm sure they are out there. Also I would stick with the factory EFI system.

GEM930

If the exhaust won't bolt up I'm kinda dead in the water (no pun intended). As far as the EFI, I need one which I can run open loop, because I will not be able to put an O2 sensor in the wet exhaust. Also, I have the unit and would like to use it, I don't have the stock computer for the LS1. It seems if I have to swap intakes, heads and cam I might be money ahead to buy the marine engine. Can the stock intake and injectors handle 375 hp? Is the valve train roller? The marine engine has roller cam and rockers and aluminum heads (I don't now which heads). If I went to a new roller cam and roller rockers and fattened it up with the programable ECU what kind of HP might I see keeping the stock intake and heads? Of course I still need to fabricated an exhaust.

Thanks for your input.

GEM

TAQuickness

iTrader: (28)

I would think it might be cheaper to buy an marinized (sp) engine. I haven't met too many folks that had a easy time taking an automotive motor and putting it in a boat.

If it flies, floats, or has *****, it ain't cheap...

kickassT/A

iTrader: (3)

all ls1's are roller cam, aluminum block and heads, and have roller rockers. stock intake and injectors can definately handle 375 easy, since mine are doing around 420 flywheel no problem. the dry wieght on an ls1 motor oil pan to intake is 390 lbs. i belive a 350 is in the 550-600 rane, but not positive. also, with a decent heads/cam setup, 500 flywheel hp isn't hard to get.

GEM930

I'm starting to think that the marine engine might be the best way to go, but I like the edea of saving 200 lbs weight - big deal in a boat. The marine engine is $7800. If I can pick up the LS1 for $2500 that leaves me with quite a bit to do the job right. A marine starter and alternator are about $200 each and the bell housing is $350. A closed cooling system will set me back around $400. Are the motor mounts the same as a 350? If so, the exhaust would be my only problem, that and getting another 50 hp. I'm still not sure the best way to get that. Can I do it with cam and computer only? If I have to buy new heads it starts to become less cost effective. The marine exhaust is expensive ($1200), but I think it is performance oriented - 4" each side. If it won't bolt up, however, it is not going to do me any good. Any ideas??? You guys are great! Also one more question, why does the Vette have more HP than a Camaro?

Thanks again.


Gem

strife

HSV did something a few years ago

http://www.hsv.com.au/news/2001/r8boat.htm

kickassT/A

iTrader: (3)

a mild cam will net you the power you want. my mti t1 cam (221/221 .558/.558 lsa112) put down 363 rwhp through an automatic tranny with stock throttle body, pulley, and ls1 intake. add another 15-25 rwhp with those mods. you can get intakes for around $300 used, pulley about $200, and you can port the tb yourself to save some money. that cam can be found used for another $250-300. as for the motor mounts, they are different. keep us posted as to how this goes... i was kinda thinking about doing something like this for my senior design project in a few years. hope this helps.
Jordan

GEM930

I'm a little confused, did you get 363 rwhp with the cam only? Are you running a stock ls1 intake? Also, any head work?

Thanks

GEM

DenzSS

Pound for pound, the LS1 will pump out more power than a SBC. The LS1/Gen III engines have much better cylinder heads and a lot of the SBC issues have been rectified. Having said that, a SBC is still a more common engine and has years of developmemt befind it. Both have advantages and disadvantages.

It is pretty easy to make around 380rwhp with stock unported heads, a stock LS1 intake and still maintain the torque you will need in that boat.

GEM930

Well, good news. I looks like there may be a company out there who makes marine exhaust for the LS1. They are checking and getting back to me. If a cam is all I will need for 375 HP I might just give this a shot. Any recommendations on a cam? Remember, I won't be winding much past 5000 rpm.

Thanks again for all your help.


GEM

grooves12

There DEFINITELY are companies out there that will make Marine Exhaust, and many other Marine-specific LS1 items. The LQ4/LQ9 is an OEM piece in many Boat manufacturers lineups. As we all know everything interchages from those engines over to the LS1's.

http://www.gm.com/automotive/gmpower...0_brochure.pdf

But, Malibu Boats actually offers the all aluminum LS1 as an option on their boats.

You might want to check with www.indmar.com ... they are the supplier of engines for most of the boat manufacturers. You might be able to source some parts from them, or get a complete setup ready to go, complete with a warranty.

LEATHL_WS6

GEM a couple of things.

Remember the power theses guys are talking about is at 6k or there about. Not 5k. If I was you you I would be looking for a motor that makes good Torque at 3500 to 4000. No doubt that is where you motor will spend most of its life.

6.0L are you talking about a 383? If so thats a good torque motor. That what you want for a boat. How big is the boat?

I feel you would be better off with a cast engine for marine use. A boat will really tax a motor like going uphill pulling dead weight all the time. If you could fit a BBC 454 or such that would be the way to go. Or a nice 383.

As much as I would love to see an LS1 in a boat I wouldn't do it. And I have thought about it before I have 2 speed boats one runs 60 and the other 73. I almost put an LS1 in my 25 ft sunsation.

Rob