GPM

Not that it matters but I like the Brodix heads, you'll like the stroker motor.

endeavour32

iTrader: (4)

I would scrap the Brodix heads and go for the AFR 265 ovals. The Brodix ovals were the best until the AFR's were released now they're second best. For your heads and valvetrain I would call Marine Kinetics, his prices were better than anyone else when I was last looking. Plus you'll get a custom cam. I used Bob on my last engine build, not only did I learn a lot, I ended up with one great engine that made power than other cam designers said couldn't be done in a boat. I'm sure others will chime in and I know they will all give Marine Kinetics two thumbs up Here is their number, do yourself a favor and call them before you make any additional moves! 585-654-8583

paintman

Hey guys thanks for the advice and input...

I've got some more info on the brodix, wanna also no if this is a good choice? Below is the info from builder

"oval port alum. heads, 270 cc intake runner, 119cc on the chamber size. rpm range 200-6500. right where we want it and with 9.5;1 compression."

Rookie

iTrader: (4)

What cu/in engine??? Are you not going to be over 500? They will not flow to 6500 IMO.

paintman

Think the final cc is 498...+ I'm runnin a b1...so wanna it to be a touch over 500hp. I'm guessing its going to spin it 5200-5500

kvogt

What boat are these engine(s) going into?

A.O. Razor

Regarding the corrosion of the alu heads, have them hard chromate surface treated . I know dart does, but I think Brodix does as well. For 500 hp, I'd think you should look into the Dart Pro1 275 oval marine heads too.

endeavour32

iTrader: (4)

Just for comparision, The engine that I used the AFR's on was 439 CI. I had a custom cam, AFR heads and Holley HP carb which was flowed at 830 CFM. My engine made 1.2 hp per cube. On a 498 with the same set up it would be 597 hp. This engine idled perfectly at 700 rpms and exploded when hammered from the 3000-4000 rpm cruise. Do yourself a huge favor and call the number I posted. I'm not suggesting you use a different engine builder, but it sounds like your looking for some solid advise. You'll get no better advice on your build by calling Bob first. He sells Brodix and AFR heads and he'll explain the advantages of the AFR.

ROTAX454

How about this 454?
http://store.gmperformanceparts.com/store/SelectProd.do?prodId=8190&redir=true&manufacturer= GM&category=Engines&name=LSX454%20Crate%20Engine&m odel=<!--19244611-->

paintman

Going to have my engine builder call bob thanks for his info, should be hittn dyno in 3 weeks