Chevy LS or newer LT?
#1
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Joined: Jan 2002
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From: Further South East of Dome Island
Chevy LS has been around for 20+ years now and there are some marine applications out there, like the Ilmor 570. Has anyone ever put one of the newer Chevy LT motors in a boat yet? Seems like outboards are winning the battle but the new LT would be great in a boat.
#2
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From: Merritt Island, FL
Way more power then the current HP500EFI, lighter, more room and 3 year warranty. You can get them with E-Top headers to help how they look.
https://marineenginedepot.com/new-62...-airpac-620-hp
#3
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From: Further South East of Dome Island
That is amazing,,, as is the price, not as bad as I thought tho. Nicely marinized. Says inboard setup. Add a Bravo bell and go sterndrive.
Direct injection at 2900psi and variable valve timing yield a very nice torque/hp curve.
Direct injection at 2900psi and variable valve timing yield a very nice torque/hp curve.
#4
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Joined: Jun 2007
Posts: 7,297
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From: Merritt Island, FL
They have a pretty generic dyno curve on this site TQ numbers are nice.
https://www.kemequipment.com/marine-...#product-title
https://poweredsolutions.gm.com/products/lt4-engine/
#5
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From: Cheboygan, MI
Check out the offerings from Blue Print Engines.
https://blueprintengines.com/collect...r-up-to-800-hp
https://blueprintengines.com/collect...r-up-to-800-hp
#8
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Joined: Aug 2021
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From: Hawaii
I’m doing the LS swap right now. The build was straight forward but hardest part was using higher end everything (bearings, rings, etc for higher prolonged rpm use)m high cost of exhaust manifolds around 2k, and then the cost of closed cooling about 1-1.5k.
those LT4’s look awesome. Small pulley upgrade and tune you got 700hp. I haven’t explored a swap for that.
I got a 5.3 for free out of a 2008 Silverado. Tore it down to block. Deleted dod, new cam, ls7 lifters, new main bearing (kings xp), new cam bearings (clevite heaviest duty I could get), new connecting rod bearings (kings xp), new pistons, rings, valve spring upgrade, new timing chain, trunnion upgrade, valve job, custom tune. May go term x if they ever come back in stock. I did get the flange adapter from marine engine depot and some other cooling system parts from them. My experience was they wanted to sell a whole engine not parts. Cool and all but customer service could’ve been better.
I anticipate 450hp with accessories more like 400. Should be perfect on my bravo 3. I wish it’d been a 6.0 or I had the money to stroke it to 383. But such is life.
mostly summit and then the mercruiser bell housing and coupler. Note you need a generic gm flywheel not a flexplate to mount the coupler to. I had to drill 2 holes in bell housing but was easy.
I think the LT is the future but the LS isn’t going anywhere.
those LT4’s look awesome. Small pulley upgrade and tune you got 700hp. I haven’t explored a swap for that.
I got a 5.3 for free out of a 2008 Silverado. Tore it down to block. Deleted dod, new cam, ls7 lifters, new main bearing (kings xp), new cam bearings (clevite heaviest duty I could get), new connecting rod bearings (kings xp), new pistons, rings, valve spring upgrade, new timing chain, trunnion upgrade, valve job, custom tune. May go term x if they ever come back in stock. I did get the flange adapter from marine engine depot and some other cooling system parts from them. My experience was they wanted to sell a whole engine not parts. Cool and all but customer service could’ve been better.
I anticipate 450hp with accessories more like 400. Should be perfect on my bravo 3. I wish it’d been a 6.0 or I had the money to stroke it to 383. But such is life.
mostly summit and then the mercruiser bell housing and coupler. Note you need a generic gm flywheel not a flexplate to mount the coupler to. I had to drill 2 holes in bell housing but was easy.
I think the LT is the future but the LS isn’t going anywhere.




