If you use thick head gaskets to lower CR on an LS motor, you completely lose the quench turbulence that prevents detonation. You need to keep the squish clearance under .050" and use dished pistons.

You also need to come to grips with the difference between a 700hp LS set up to live in a street/strip environment vs performance marine duty. Marine usage demands full continuous output at higher speeds, with no load cycling.

A lightweight boat running wide open for shorter blasts can make do withdturbo'ed junkyard donors. You'll end up disappointed if you plan to push a serious performance hull hard 30 minutes at a time..

i have no problem putting a set of good rods and offed pistons in an ls.
I’d like to try to run the stock motor and probably will for the first pair. See how they hold up and go from there.
Old school sbc engines are nowhere near as stout as an ls engine and they seem to last forever in boat of every shape and size.
Thanks for the heads up on keeping min .050 on the squish. I spoke with shafiroff racing about that today he didn’t give me a dimension just told me to change pistons Instead of putting a really thick head gasket in it.
Since the engine make 695hp @ 5.5 lb of boost, I would set it up to run 5 lbs, I think it should live a long healthy life at that level.

Party on! Keep us posted with the outcome as we all appreciate the info. A build thread would be awesome!

Im looking at what’s out there for water jacketed turbos. I’m sure there is one that will work for this application I just need to find It.

hell it it doesn’t work I can always sell the parts on eBay and go with old school 406 engines.

Please point us to the website that shows a 695hp LS at 5.5 psi of boost. At 6,000 rpm, that works out to 610 lbf of torque. A 400 ci LS motor will struggle to deliver 380 lbf of torque above 5500 rpm. Working backwards, you need to boost the motor to 156% effective torque capacity. Disregarding dynamic losses in the induction system, you will need a minimum of 8.4 psi of boost AFTER cooling the incoming charge back to within 10% of ambient temperature in order to approach what you describe.

I'm not doubting your recipe. I just very much want to see it, and the accompanying data.

Please link us up.

M

Check out my thread entitled

What’s out there for Chevy LS based engines

there are two videos of the guys with the LS dyno runs

I had a set of CHIEF built 502s with Blower Shop 6-71s with aluminum dart heads. They made 675HP on the Dyno. Never had intercoolers. Ran premium gas however. They had alot of reliable hours on them before I traded them in. This was a few boats ago.

how many lbs of boost did they make? Thanks

Go easy on the throttles big daddy!!

hey brother how you been?

I hope you’re well.

Still have your skater turbine?

I can’t go easy on the sticks! Lol