I'm hoping some of you guys might be able to tell me about how much HP my engine might have. It's a 454 bored .30 over. L2465 pistons, Performer dual plane intake, 750 Holley, roller rockers, Stainless marine Hi torque dry exhaust. Cam specs - 274/282 duration, 576 lift. I believe the heads are the larger oval ports, mildly ported. I know these specs are pretty vague but I'm just trying to get a rough idea. Also I am just putting the boat back together after a complete re-rigging which included a TRS to Bravo swap and need to put a new exhaust on. I'm thinking of going with a wet exhaust this time. At what point does cam size become an issue with reversion. Next winter I will be rebuilding the motor and in case I go with a bigger cam I don't want to change the exhaust again. Any recommendations on exhaust systems.
Thanks

I'd say you are 475-500?
call stainless on that exhaust question... Brownie is very knowledgeable.
My rebuild is similar to that and i went w/ long risers.

I was going to use my SM manifold since they are in excellant condition and just have new pipes made, but SM wants more just for pipes than I can get a Revolution system for. I hear there pretty good plus I can sell my SM system.

Those engines specs are close to the engines I am building for my boat this winter. DD2000 says about 500hp at 5300rpm and 550ish ft-lbs in torque at about 4100rpm. I would definately stay with the stainless marine exhaust if it is the hi torque version. True length headers would be the best but they can get expensive.

BT

I agree with the others. It sounds like your 454 engine has a good parts combination, and in the ball park for making somewhere between 450hp and 500hp or so.

I think the SM is a better quality product.
I got my new risers and they look like art.
Call fred/trickmarine... he's got $0.02 to spare.

Desktop Dyno sounds optimistic.
I would agree with 450.

More detailed cam specs and better verification of your heads and valve sizes would help.

Sounds closer to the old 420 HP Mercury of the 1980's

[QUOTE=mcollinstn]Desktop Dyno sounds optimistic.

DD2000 is for my engines, which are slightly different than his... .070 over, more cam, rect heads true length headers. 450hp is probably close on his engine with good exhaust.

BT

[QUOTE=blue thunder]What kind of HP is your engine putting out. My engine originally came with rectangular port heads and a 600 cam. Would I gain anything by putting that cam back in? At what point does the cam become a reversion problem?