OK to Boost?
 

I have a 454 Mark V block, forged crank,ISKY model RR-275/284 cam, J/E forged pistons, Merc square port heads, dart single plane intake.

The current compression is 9.8/1

I can only get 91 octane being on the west coast. Do I have any chance of running a low boost (3.5-4.5 psi) procharger or whipple with a supercooler. I'm in Las Vegas so the summer temps hit 120, thus the supercooler.

I would like to add the boost without going inside the engine but is this realistic at 9.8/1

Re: OK to Boost?
 

The Marine Performance Chart from B&M says no! you are to close to the effective compression ratio of 10.75:1. I posted this chart in an earlier post!

http://www.offshoreonly.com/forums/s...48#post1046248


Bryan

Re: OK to Boost?
 

on mine,i've ben running a B&M 250 for 3 yrs with 9-1 comp. 6-7 lbs of boost,last year i added a inner cooler,pulley change so i'm still at the 7 lb mark w/93 octane.now i have a 420 mega blower coming for next year,the only time i hold my breath is when i bring it up to 6000 rpm's and the guy next to me ain't letting up,so i ain't either til either i pass em or it's even.i guess sometimes you have to use common sence.your compression i don't think i would do it with it that high.