arnett

Actually there site may be lacking but they have built a lot of marine engines, they do a lot of 454 to 511 strokers. But anyway I personally called and questioned the cam grinder from Erson. He said he new he was being conservative with this grind because of reversion concerns. His thought was if we can't crank up the hp lets make a torque monster, which is what a Mercruiser engine needs IMO. His estimate was 460hp @ 5000 and 561ftlb @ 3500rpm. (520ftlb @ 4500) and 500ftlb @ 2000rpm. He calculated this "mild" 222/226 114 +4 .55 lift cam grind to create a flat torque curve. And at 450+ peak hp @5k I believe this build is correct for what I'm trying to accomplish. 450 hp 454 that won't revert water with more torque than a 502 HO

SB

iTrader: (1)

The cam's biggest concern on a wet exhaust boat is the exhaust. The type of exhaust you have, Erson picked a decent cam.

However, the 10:1 compression and rectangular 320cc Profraud heads don't make sense for the rest of the build.

One thing effects another.

The exhaust in this application limits the cam.

Since the cam can't be really any more than they picked, the compression and heads are not close even to ideal.

That's all. My IMHO.

arnett

I questioned the compression ratio because I figure with that cam cyl pressure would be too high but he says he calculated that into the grind and it was ok. If I stuck with lesser comp and reduced cyl pressure hp and more importantly torque would be significantly less. All I ever run is premium fuel anyway.

As far as the heads they are good as long as machinist checks them and assembly's them their selves. Oaks machine agrees never to buy pre assembled PC heads as a bolt on and go part.

MILD THUNDER

iTrader: (3)

Have you put a compression and tester on the engine yet?