zimm17

It looks to be about the same price ($5000) to add a blower or go with AFR heads/roller cam/lifters/pushrods/rockers for my 454 magnum carb'ed motor.

Right now it has 20 hours on it since a rebuild. Has Dana exhaust and edelbrock air gap performer rpm intake.

I was looking into the procharger setup and the whipple charger as alternatives too.

I don't really like how the procharger "hangs" off the engine, but it will fit under my engine hatch.

The whipple looks the best, but would require cutting a big hole in my engine hatch and adding a scoop, plus painting it, or spending more $$$ and adding EFI at the same time. I have no idea how I would do that though.

Adding heads and valve train would easily fit, but I don' t know how much more power I can expect over my stock engine.

92 octane pump gas is not problem, I trailer the boat.

I spend most of my time cruising 3000-3500 rpm with the occasional WOT run for a few minutes at a time.

Or I could just give up and swap in a different motor like a merc racing 500EFI or 525EFI takeout...

I'd like to hear from those who have done one or the other- not looking for an offer to buy anything from ya'll yet (sometimes I get a sales pitch, not advice)

BajaRunner

id do the supercharger

PatriYacht

Unless you're going to really spin that 454, you won't see much hp from the AFR heads. The GM rect port heads are already too big for a 454. The only improvement is on the exhaust side and that won't make that much hp. The blower on the other hand can get you a 50 % gain easily.

KAAMA

iTrader: (1)

I once had a pair of 454's (actually 468cid) engines in my 32' Active Thunder. They had a Dart single plane intake, Holley 850cfm carbs, Merlin OVAL port cast iron heads with 2.30" intake valves and 1.88" exhausts and were nicely ported in the bowl area/short side radius, Crower solid roller cam with about .650" lift or so, 9.5 comp ratio, and they made something like 600hp @5500-5700rpm, and about 590lbs of torque. So it CAN be done, but they were high maintenance engines!

I would rather go with a hydraulic roller cam, and a supercharger on a 454cid engine---they'll be a lot more user friendly and you'll make more power.

rdoactive

Supercharger + blower cam. A roots blower would probably be more economical and easier to set up. And I like the look of scoops!
Gary

zimm17

Cool- so something like a blower shop 6-71 with a pair of holley marine four barrel carbs? Any recommendations for carb setup?

Another issue- would I be able to keep my closed loop cooling system intact? I don't see where the thermostat housing fits on a blower intake.

I have a picture at http://zimm17.com/id27.html

rdoactive

The thermostat mount usually come out the front of the manifold on larger blowers. BTW, Merc and Hawk use a 177 for 5psi on their 454 motors, although they do spin them kind of fast.
A 177 or 250 should be more than enough fora 454 and will be lower profile.
With the 177 you can use a single carb, a merc-like cam and more or less copy their old 525sc. One of the best motors they made.

SkiDoc

iTrader: (4)

Tyler Crockett can sell you an excellent blower package for the boat. My 454 mags, 600+Hp, head work(I went with Brodix custom ported BB-2's although he said he could rework my stocks with close to same power) These motors idled like EFI. He sent me all the components including the right carb, I put them on. Anyone would be happy with these engines!

Strip Poker 388

iTrader: (6)

I started out with a 365 mag with merlin heads and a HYD roller.Made 762Hp on 93 at 6700rpm. You could make a cheaper packaged with less HP and be very reliable.Not sure about the cooling system fitting though ?

obsessioncatsass

hey zimm 17 how do you like the dana exhaust? Did you get noticable difference in power?