hadleycat

I have a gen v 454 mag it is all stock except for 496 exhaust. Currently has 150 hours on it. I am already thinking ahead to next winter when I plan on pulling the motor. I would like to bump the horsepower up to about 450. At this time I am thinking roller cam and lifters. Roller rockers. Intake manifold and Holley carb. Really do not want to get into the bottom end. This will be my first time tearing into a marine engine. Although I have rebuilt motorcycle engines before. Any suggestions?

endeavour32

iTrader: (4)

You can most likely make that power by simple adding a roller cam, lifters, rockers and carb. Call Bob @ Marine Kinetics he'll set you up with a plan for the entire package. I'd say plan on around $1500+/- for everything.

hadleycat

Yes I definitely plan on contacting Bob @ Marine Kinetics when I get the motor out. I am curious if my stock oil cooler will be up to the task. Also not sure if I should do any head work.

hadleycat

Does Bob work with a customer on the total package? I was under the impression he dealt specifically with cams.

endeavour32

iTrader: (4)

Bob will work with you on 100% of the build. You will need to beef up our oil cooler but thats only about $150 from Mr. Cool. I'm doing the same basic build on my 454 Mags. I'm rebuilding them though as the hours on them are somewhat unknown. As far as head work, you could have Jim Valako in Grand Rapids do what ever you need done. But to hit the 450 mark you can do that with what you have. Porting on the mag head is most likely good for 50 hp or so.

wannabe

Find an HP500 carb and manifold, they work great at that power range. There should be people that have them lying around.

I have them on my 454's w/ crane roller cam and dart iron eagle heads- dyno at 475.

Wannabe

buckknekkid

Which cam?

TBAG

Could you give me a little more details on cam specs and heads? Sounds exactly like what I want to do on mine this winter.

Thanks

stickman811

I'm planning on virtually the same thing, and $1500.00 is a steal when you're talking adding 30% HP. Would you guys recomend a true double roller timing setup or would you guys swap it to a gear driven timing setup? 5000 rpm's seems so high to me for a Big Block, I'm still getting used to the whole idea but that's the Car guy in me. I eventually want to run a 23 or 25 pitch prop without being last off the line and am looking for my Winter Project as well. I've got a 65 mph. Boat as it is, but Faster is always better. My Father In Law has a much larger budget and I want to make sure My winter project yeilds speeds that will keep me ahead of him!..LOL. "I'm Nailing Your Daughter and My Boat's Faster than Yours!" "Merry Christmas!"

hadleycat

I have a Powerquest Spectra 22, very similar to your boat, and am looking to get close to 70. I am at 62 with a 454 mag with 496 exhaust manifolds. The manifolds gained me 1.7 mph. I am running a Mirage 23 prop.