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Re: How do I get ~450hp out of Merc 454 -95?

I didn't really count on this kind of interest in this tread...

I thank you all for the all the valuable answers. All I have to do now is to persuade my two "partners" in the boat... But since we have a 350 that we are gonna fix and sell during the winter, that shouldn't be a problem! :eureka:

It's pretty sad that here in Sweden the 174 costs about $4000 and a new carb is about $650. So Im gonna look around in the states for a good price since the customs and taxes ads about 30% if I import the parts...

The boat makes almost 60 with the 454 and a Mirage 27P, I have to get a 25P to get it up to ~4500rpm. So about 10-15 more I hope... But you never get satisfied! :D

Thank you all,

Tomas

Re: How do I get ~450hp out of Merc 454 -95?

Quote:

Originally Posted by Budman

Can anyone answer my original question? My engine already has about 9.2:1 CR. Is this too high to run a supercharger, even with 93 octane? Would 4 psi of boost be too much for this setup? Is so, do they make pulleys that will reduce boost below 4 psi?

Alternative would be to build a 502 and stay normally aspirated. My current 454 only has about 200 hours on it. It is based on a 2-bolt cast crank motor, but has forged pistons, polished & shot-peened rods with the ARP bolts, ported oval heads (upgraded to 2.19 valves), etc...

Thanks, Tom

Budman! I Agree with Gary 9.2:1 is asking too much for 92 octane pump fuel! At 9.2:1 and 4 psi of boost it puts you above the effective comp. ratio of 10.75:1 to run pump fuel! That added with the air-fuel temp rise and no inter-cooler, just not a good candidate for a blower on pump gas!
And Gary you are absolutely correct, that on the 330 upgrade no ignition change is required, but I just love those DUI so much, they are so clean and run so crisp, if my Hummer wasn’t a Diesel I would have one in that as well! Cheers! :D