Twin Turbo LS Boat Engine
Thread Starter
On The Tree
Joined: Feb 2016
Posts: 116
Likes: 0
Twin Turbo LS Boat Engine Hi all, new here and after some advice on a set up for my race jet boat. The plan is to run an LS engine, Twin turbo, air to water cooler, leave bottom end stock, do a cam, springs and injectors to suit. Now I normally play with a dirty old SB Chevy with carbs and a 671 so going down this way is all new but believe its the way forward, just need to research and learn. The engine will be running for extended periods of time in the 5000-6000 rpm range, so for starters what LS should I go for? It needs to be reasonably affordable and available down here in New Zealand so when it pops I can get another easily and transfer the kit over. Was thinking the 6.0 LQ4 engine cast block alloy heads 9.4:1 comp, but am open to any ideas. Have read good things about the 5.3 engines taking boost, but the smaller cubes seems a backward start considering I will be running in a class with 1000HP big blocks. So if I go the 6.0L what should I use for headers? The engine sits in a open engine bay so theres plenty of room. What turbos should I use? Internal waste gates or external? How big? Found these nice 417 Motorsports air-to-water intercoolers that go into a Holley HI Ram intake. Pricey but look tidy, are these any good for my application or would a external cooler be cheaper and just as good or better. Would be hoping to get as much HP as possibly reliable on 98 octane pump gas, 600-700?. Any help or advice will be appreciated, thanks
Last edited by Huffa; Feb 16, 2016 at 02:52 PM.
On The Tree
Joined: Jan 2015
Posts: 102
Likes: 0
From: New Zealand
I'd also go iron block but they're harder to find here in NZ..
Most of those 5.3s making big power, do it for seconds down a drag strip. That's nothing compared to the beating you'd give it on a river. Has anyone else had had success with this approach and application? Reckon you'd need to turn it down a bit.
Most of those 5.3s making big power, do it for seconds down a drag strip. That's nothing compared to the beating you'd give it on a river. Has anyone else had had success with this approach and application? Reckon you'd need to turn it down a bit.
Trending Topics
Go with whatever LS motor you find cheap enough. If it's an LS1 or another higher compression Shortblock, there are different combustion chamber ratio heads to get it down in static compression. Then have your cam spec'ed to get the dinamic compression where it needs to be. Last but sure not least, get the right tuner to polish that to a nat's ***. It will live much longer than you may think @ 700HP.
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 Thread Starter
On The Tree
Joined: Feb 2016
Posts: 116
Likes: 0
So if I plan to run up to say 800HP with twin turbos does that mean I only need two turbos capable of 450hp each? Looks like I will probably use the truck manifolds, do I run internal or external waste gates? Cant see boost going past 12-15 psi max, plan on running way less if I can get the hp I need. Would these be pieces of? I will only be running 4 or 5 races a year at this stage so not going to get thrashed every weekend, could they hold together?
http://www.trademe.co.nz/Browse/List...?id=1036098899
http://www.trademe.co.nz/Browse/List...?id=1036098899
TECH Addict
Joined: Aug 2004
Posts: 2,866
Likes: 4
There have been a few guy on here use LS engines in boats. Worth having a bit of a search and see what you can dig up. There has been some talk about how turbos on boats respond. I do to want to say something that's a load of b@llocks so will let you find it. 
Launching!
Joined: Jun 2006
Posts: 209
Likes: 2
From: Middle of MI
Just make sure that whatever engine you end up getting, prep the lower end accordingly. Starting with a solid foundation will pay dividends down the road, even if it's a little more cash up front. Looks like a sweet boat, can't wait to see it flying down the water!
huffa asked about the turbo....& I will ask what hull and part of the country are you in?
I have a Hamant (hull) that I'm going twins on (ls6), stinger box....Microsquirt v3. (Denmah edition!).....south Florida.
I've searched and haven't found much to read on turbo (boats) in general....how they act in refence to the loads we have with props / or hull (resistance =constant work load)...
Have you guys??
I have a Hamant (hull) that I'm going twins on (ls6), stinger box....Microsquirt v3. (Denmah edition!).....south Florida.
I've searched and haven't found much to read on turbo (boats) in general....how they act in refence to the loads we have with props / or hull (resistance =constant work load)...
Have you guys??
Thread Starter
On The Tree
Joined: Feb 2016
Posts: 116
Likes: 0
huffa asked about the turbo....& I will ask what hull and part of the country are you in?
I have a Hamant (hull) that I'm going twins on (ls6), stinger box....Microsquirt v3. (Denmah edition!).....south Florida.
I've searched and haven't found much to read on turbo (boats) in general....how they act in refence to the loads we have with props / or hull (resistance =constant work load)...
Have you guys??
I have a Hamant (hull) that I'm going twins on (ls6), stinger box....Microsquirt v3. (Denmah edition!).....south Florida.
I've searched and haven't found much to read on turbo (boats) in general....how they act in refence to the loads we have with props / or hull (resistance =constant work load)...
Have you guys??
http://www.trucktrend.com/how-to/eng...5-3l-big-bang/
9 Second Club
Joined: Nov 2003
Posts: 13,616
Likes: 185
From: Norn Iron
Unless you're going to pulling a lot of rpm's, cant see the likes of a HiRam being of any benefit over say a plastic truck manifold. It may even be worse in the range you're working.
Unless you insist on using it because of the cooler kit.
A pair of smaller BW would easily meet the power needs and spool quick and lower rpm for lower boost options too.
http://www.agpturbo.com/borg-warner-...1-12709095019/
or you could go a little larger
http://www.agpturbo.com/borg-warner-...1-12769095003/
For only 800hp there probably isnt any point going bigger even with the extended duty they will see.
As for which base engine, just find whatever LS equipped vehicle is most common in breakers yards there and start from there.
It would make sense to fit decent rods and pistons at least, choose a CR to suit your fuel etc Again no sense pushing this too high to take risks given the application.
Pair of LSA heads or similar and ARP studs/LS9 gaskets and it should be good.
Unless you insist on using it because of the cooler kit.
A pair of smaller BW would easily meet the power needs and spool quick and lower rpm for lower boost options too.
http://www.agpturbo.com/borg-warner-...1-12709095019/
or you could go a little larger
http://www.agpturbo.com/borg-warner-...1-12769095003/
For only 800hp there probably isnt any point going bigger even with the extended duty they will see.
As for which base engine, just find whatever LS equipped vehicle is most common in breakers yards there and start from there.
It would make sense to fit decent rods and pistons at least, choose a CR to suit your fuel etc Again no sense pushing this too high to take risks given the application.
Pair of LSA heads or similar and ARP studs/LS9 gaskets and it should be good.