LS184

iTrader: (7)

this guy put one in his ski boat https://ls1tech.com/forums/general-lsx-automobile-discussion/931024-my-ls1-powered-ski-boat.html

Compressor Surge

iTrader: (21)

I just replaced the HEI distributor module with an MSD unit, MSD cap and rotor, MSD wires, and set the timing to ~8 initial at 700 rpm, and 36-38* at 3000 rpm

Also just pulled the carb off (750 cfm Carter AFB) and cleaned it out good, and blew everything out with compressed air.

Finally got it running right (so it's not popping) but it's SLOOOOOW....

Going to run the valves tonight, seem to have some valvetrain clatter.

My buddy has a 750 demon that I could try out. I don't really want to stick a bunch of $$ into the big block if I'm gonna offload it for a different motor.

If it comes to it, I will live with it the rest of the summer and tear into it this winter

VintageCamaroChris

iTrader: (3)

ya 47 is way slow for that. You can probably pick up a decent intake on ebay for cheap, I would look into an edelbrock air gap or even a single plane for that since you'd be in the mid range or upper rpm range most of the time. Just seems like with even a tired big block you should be able to get 55-60 without a problem..

LS1GMCTruck

iTrader: (2)

Anyone that has any experience with big block jet boats knows that this is a very typical speed. Its a jet, which is very inefficient, compares to a propeller. With the same power, this boat would be 20 m.p.h. faster with a propeller...minimum. Replacing the bigblock with an LS series engine is just putting good money after bad, and I think you would be very disappointed in the boats performance. Again, not due to the LS power, but due to it being a jet.

Compressor Surge

iTrader: (21)

I am aware that jets are inefficient on the top end. However, I have two good friends here with jets that haul....but I guess they are making LOTS more power than me.

One is a Hondo flatbottom with a 535 cid big block chev, his runs about 83.

The other is a Nordic tunnel with a full roller 468 with a tunnel ram and dual quads. His runs about 87 mph.

I do realize that the secret to speed on a jet is in the pump setup.

However, I'd like to swap an EFI LSx because
1) It's different. I've NEVER seen one in person. BBC jets are a dime a dozen around here.
2) I've already got a spare Vortec engine sitting around
3) I love a challenge
4) The reliability, ease of starting, and idle quality of an EFI engine
5) HUGE weight reduction going to an LS vs the ALL IRON big block.
6) If it doesn't work, I'll sell it and buy something else

That said, I was able to squeak 53 mph out of it tonight with 3 good sized guys. Tweaked the timing a bit, and it woke it up a bit more. I don't want to push the timing any further until I can get some better fuel in it.

The research continues.

BTW, what's a complete, running 454 roughly worth?

G-Body

iTrader: (4)

I will measure everything up when I get a chance. I have a SBC/BBC flywheel driveline that I can measure....I think I can pull it without pulling the engine (the engine is just propped up on boards.......yep I`m in the middle of a jetboat project too ) If it slides right out I can probably measure that tomorrow, if not probably next week....as the engine has to come out anyway.

As for parts theres tons of places, I usually hit the forums first
www.riverdavesplace.com
www.performanceboats.com
www.hotboat.com/forums/index.php
http://www.banderlog.com/phpBB2/index.php
http://www.jetboatracing.com/phpbb/index.php

http://www.jetboatperformance.com/
You can also find some stuff on e-bay

MastMotorsports

This looks like a cool project. We also do LS series engines for marine retrofits, OEM marine applications, and the airboat industry. Keep this thread updated with your progress.

Shaun
Mast Motorsports
High Performance Powertrain Solutions
shaun@mastmotorsports.com
www.mastmotorsports.com

Fred O'Bannion

iTrader: (-1)

now this is a great idea.

frated420

Got a 440 LS that would be perfict in there, should make 780 FWHP on the motor. We were told to shift it at 8500 if it was still makeing power at 8K.

Z284U2TRY

iTrader: (5)

I would check the wear ring and impeller clearance. I bet its cavitating.

G-Body

iTrader: (4)

What do you guys do for marine starters and alts? In an application like his it isn`t really an issue since the engine compartment is open so it does not require marine stuff....but I have a closed engine compartment.

I have seen more than a few LSx`s in closed engine boats and it looks like they use the GM alternator.....does someone marinize the GM alts and starters? Just a curiosity thing....for now....my boats getting a 305 to get it together and running because I have one and used mercruiser marine parts for SBC`s are dirt cheap.....well dirt cheap for boat (B.O.A.T. = Break Out Another Thousand) parts LOL

LS1GMCTruck

iTrader: (2)

Buying a marine alternator & starter is your only choice. They can be purchased on-line or through any marine supply company or marine engine & parts dealer/distributor. Jerry's Marine Service is a wholesale & retail marine engine parts distributor, for instance. You name it, they have it...in stock. www.JerrysMarine.com This aside, a marine alternator & starter does not make a marine engine. Going into the details between the two would be endless, as every base engine differs in its marinization.

G-Body

iTrader: (4)

I measured the LSx and SBC/BBC crank bolt spacing. The SBC/BBC has 6 bolts evenly spaced on a 3 and 9/16" circle, the LS motors have 6 bolts evenly spaced on a 3 and 1/8" circle. I don`t really think you could modify the driveline to make the boltpattern smaller, even if you weld the old holes shut, I don`t think there is room to put new holes in on a smaller circle. However you could make an adapter to go between them. Just like the PTO adapters that they use on newer style jet drivelines. If you made the adapter out of 1/2" steel plate and countersunk the boats you might still be able to use your mounts and bellhousing.

G-Body

iTrader: (4)

I snapped a couple pics of my current project. Its a sleekcraft monterey. Getting the old 305 from my El Camino for mock up purposes and maybe till the end of this summer.....after that who knows what engine its getting

Compressor Surge

iTrader: (21)

Thanks for the info, Gbody. Looks like you've got a LOT of work to do....but it'll be a nice looking rig when you're done

Oh yeah, found out why my 454 was down on power.....I guess it ran ok for only running on 7 cylinders.

G-Body

iTrader: (4)

LOL, that was actually one of the first things I thought of. When you said only 47mph and I saw the pics of the boat I was thinking WTF is that thing only running on 6 or 7 cyls?

I should have thought about the cam, my dads 454 ate a cam when we first put it together. BBC`s are know for eating them especially now days with the crappy emissions oils. You should run a diesel truck oil, or a racing oil with the higher zinc content. A few years ago the standard passenger car oils were reformulated and they don`t have enough zinc in them for flat tappet cams, it didn`t hurt todays cars because most run roller lifters....but it is killing a lot of older engines.

FormulaBoat

iTrader: (1)

Who makes these manifolds? I can't find them anywhere. Or, where did this picture come from? Thanks in advance. This is from picture of post 6-10-2008, time 12:12 from Compressor Surge. These manifolds are log style, not up-swept style.

LS1GMCTruck

iTrader: (2)

MerCruiser, IndMar, Crusader, all marinize GM's latest 6.0/6.2 LS base engines, and have exhaust manifolds available. There are others as well. Mast MotorSports marinizes the 7.0 Litre LS motor & can direct you to exhaust. Even though the manifolds are not in every marine exhaust company's catalog, doesn't mean they don't sell them. Call Hardin Marine, CMI(Custom Marine, Inc.), Stainless Marine, etc., and ask.

Compressor Surge

iTrader: (21)

Well it's the end of the season, and this is what I'm left with:


Out with the old....


In with the new! 6.0L LQ9










Lessons Learned:
-The truck pan is ~3" too deep, and the sump is on the wrong side. Need to research what pan will fit better.
-There is a TON of room with this LS in there, vs. the big block.
-Motor mounts should be a piece of cake!!!
-The old BBC Indmar bellhousing will work pretty much perfectly (minus the starter of course)
-The drive coupler should be pretty easy to adapt. Either by re-machining the holes, or by machining an adaptor.


Stay tuned!!

G-Body

iTrader: (4)

The GTO pan might be an option since it is front sump.