Offshoreonly.com - Chevy Crate Engines - What Need's to be Modified?

Offshoreonly.com (https://www.offshoreonly.com/forums/)

- Do It Yourself, Boating on a Budget (https://www.offshoreonly.com/forums/do-yourself-boating-budget-249/)

- - Chevy Crate Engines - What Need's to be Modified? (https://www.offshoreonly.com/forums/do-yourself-boating-budget/271669-chevy-crate-engines-what-needs-modified.html)

Quote:

Originally Posted by Michael1 (Post 3633219)

Ray, you are a wealth of information.

I've always been a big block fan, but I have to say the LS is really getting my attention now. It's amazing how much power GM is getting out of the LS engines. This really shows what new technology, and fresh computer aided designs can accomplish.

Do you think the LSX 454/620 street version, or the LS 376/525 would have too much cam overlap for marine use in terms of water reversion?

Michael

The LSX 376/450hp has the same cam as the ls3 and works fine for marine use. On the 454 it's got too much overlap for wet exhaust. I haven't looked at the specs for the 525

Thanks but I need to keep it 350 -375 hp in order to keep the alpha alive . all my time and money goes into my Skater , all I want is to do 65 in this boat I paid 500.00 for this so I can afford a few dollars to make it faster

Just pickup a Mercury Black Scorpian 6.2L at 350HP it should be a nice fit. I will not make a compatibility statement on the Alpha drive behind it as I am not a drive expert, but perhaps some of those guys can comment on that.

Best Regards,
Ray @ Raylar

Quote:

Originally Posted by KEVLARKAT32 (Post 3633508)

Great info guy's ! Curious about a GM SB as I I have a very clean 20 Ft Formula SC that has a 305 -198 HP and I would like to install stroker in it ( 350 HP ) Kind of a sleeper . Is there any crate GM SB engines that would fit this bill that I can drop in WITHOUT tearing it apart ?

Larry

I'd stay away from a stroker 'cause your alpha won't like the torque. The 330hp 350HO works well, I ran one in my 24' aluminum work boat for 3 years and now it's in a ski boat still going strong. The ZZ4 350 is the next step up and is used as a spec class racing engine in white water marathon jet boats. It requires premium fuel but will run hours at WOT without complaining. Although both engines don't need any special clearancing to be put into marine use it's still always a good idea to have someone go through them and break them in on a dyno 'cause you just never know with a crate engine. For about 10k you get a complete turn key 6.0LS with closed cooling and 385hp. That'd be my choice!

Thanks for the help and I know i'm pushing aloha beyond what its designed to to but for thirty years have always kind of pushed drives to the limit and knowing how to drive is a big plus . My buddy sells more Merc than just about anyone else ( not merc racing ) maybe I can find a CPO 357

Quote:

Originally Posted by KEVLARKAT32 (Post 3633629)

Can't beat the fun per dollar with that boat. What does it have in it now, and how fast does it go?

Michael