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

Anyone know if a 174 would work on a motor with 9.25 CR? It does have forged TRW's and Ferrea superalloy (not inconnel) valves. Cam is slightly larger than a magnum cam - 112 LSA, 229/239 dur, around .525 lift if I recall correctly. Stock exhaust with silent choice. Boat weighs around 4200 lbs.

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

If you get a good set of heads,nothing fancy but not the little ones,raise your compression to 9.5:1,put in a cam about 225/235 @.05 with 5.50" lift and some Rev marine or similar exhaust you can have 450hp pretty easy,forged stuff is really not ness. in this range and the cam will kill a little of the compression.

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

Tom I just pulled out my receipts! Total cost was $3725.10
Blower marine kit 174 $1975.00
boost gauge 47.14
msd ignition system, dist,box coil rev limit,wires, box bracket, $684.00,
you can save some money here and go with the Performance marine dist, rev limit and wires for $509.00 ready to drop in and allot less wires to hook up! and in my opinion way better! I use this distributer on my 1400 hp gale banks twin turbo BB at 6500 rpm and 25 pounds of boost!
http://www.performancedistributors.com/
throttle bracket 19.95
fuel line, pump,bracket,check valve $250.00
Carb $500.00
8x2.5 flame arst $77.00
hope this helps

Bryan

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

Opps don't forget to re prop!

$500.00

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

i used the stock ignition on mine.

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

Love my DUIs, but an ignition upgrade is probably not necessary for a 4psi motor. I've used Tbolt and V6 modules with about 28 total timing.
Stock fuel pump should easily support 450hp.
The 300/330/7.4 has a wimpy oil cooler, definitely upgrade.
The boost pressure and an oil temp guage are really good ideas.

25psi boost! That scres even me! :p
Gary

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

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

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

I'm no expert, but iron heads & 9.2:1 with a blower doesnt sound too good to me unless you have access to 100+ octane fuel. Keep in mind Merc & Hawk used under 8:1 compression on their 177 blown, 5psi, 454, 525 hp motors.
My $0.02
Gary

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

Kind of what I thought, Gary. Just wishful thinking on my part - I've been a little disappointed in the performance of this motor since I built it. Better exhaust, Holley carb, maybe better heads might wake it up, but by then I'm heading down the path of a rebuild, at least with the heads. Oh well, should have built a 502 when I had the chance...

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

do a search on dyno's 330's on roids.....505 hp at 5600....