LSx into Jet Boat??
this guy put one in his ski boat https://ls1tech.com/forums/general-lsx-automobile-discussion/931024-my-ls1-powered-ski-boat.html
Thread Starter
Joined: Dec 2005
Posts: 314
Likes: 0
From: Mackinaw, IL
well for the time being you could tune up that big block. Edelbrock carbs suck. I bet an 850 holley and a good intake would wake that thing up like crazy, every engine dyno test ive ever seen the first thing they do on a big block is upgrade the carb, and the first thing I do is ditch the edelbrock carbs. That intake mani is sure to be killing it as well, could be about 75% of the problem right there. They are OK on a daily driver but crap for RPM. Also you might upgrade the ignition system, from new plugs to an upgraded module in the HEI. All these things will give you more 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
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..
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.
Thread Starter
Joined: Dec 2005
Posts: 314
Likes: 0
From: Mackinaw, IL
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.
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?
Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
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
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
FormerVendor
Joined: Mar 2007
Posts: 182
Likes: 0
From: Nacogdoches, TX
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
Shaun
Mast Motorsports
High Performance Powertrain Solutions
shaun@mastmotorsports.com
www.mastmotorsports.com
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
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 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.
Last edited by LS1GMCTruck; Jun 13, 2008 at 08:45 AM.
Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
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.
Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
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
Thread Starter
Joined: Dec 2005
Posts: 314
Likes: 0
From: Mackinaw, IL
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.
Oh yeah, found out why my 454 was down on power.....I guess it ran ok for only running on 7 cylinders.
Joined: Sep 2004
Posts: 3,148
Likes: 12
From: Downers Grove, IL
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.
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.
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.
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.
Thread Starter
Joined: Dec 2005
Posts: 314
Likes: 0
From: Mackinaw, IL
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!!
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!!