Got my 454Mag back from the shop the other day. I did some research before hand and gathered advice from members here and other sites, thanks for the input BTW...

We came up with a game plan to setup the engine with a Procharger @ 5lbs boost so that it would be a strong, reliable runner, not extreme, just consistent....

What do you all think? And what should a "ball-park" $$ figure for the build w/dyno be..?


I pulled the motor and removed all exterior components myself and took the block to the engine shop. They did the following:

Engine was stripped, hot tanked and sonaflux.

Bore and hone with torque plate and ARP rocker studs.

Deck height checked and parallel deck block.

Alignhone block with studs, torque in bearings and measure bearing clearance for final size to finish main housing bores.

FCB finish clean block after machining.

Re & re cam bearings.

Re & re frost & oil plugs

Resize rods

Re & re pistons on rods and check alignment

Clean, sonaflux & polish crankshaft

Re & re 4 exhaust valve guides that were cracked and pressure test head. 16 bronze guide liners installed.

Hone valve guides for stem clearance.

Grind intake port floors in heads to match int manifold ports, intake port roofs of heads were already higher then manifold ports. surf. .065 off int. side of heads for manifold to fit, trial fit on engine and setup int. and machine end rails for clearance.

Blend in valve bowl area after installing larger valves, machine valve guides for positive valve seals.

Surface heads to 110cc for proper compression.

Surface exhaust side of heads, bad from factory.

Hot tank, sonaflux & valve grind heads, set installed spring heights.

Balance crankshaft assembly.

Assemble engine including file fit rings, check clearances, degree camshaft, check piston to valve clearance, check rocker geometry and determine pushrod legth, shorten outer head studs so exhaust manifolds clear when installed.

Machine heads for 2.250 intake valves, unshroud combustion chamber.


Some of the parts we used:

JE Flat top pistons and file fit rings .30 over
ARP rocker studs
HP rod and main bearings
Cometic head gaskets
True double roller timing set
Dual valve springs
Roller lifters
Scorpion roller rockers
Custom push rods
All new marine gaskets
Oil pump and drive (yes pick-up was welded in..lol)
Inconel Extreme duty exhaust valves 1.88
Inconel Severe duty intake valves 2.25
Brass frost plug kit
Valve guides


Sent my ECM down to Mark Boos for re-programing and got that back yesterday. Plan on hitting the dyno Dec. 20th....

I am pretty sure I paid top $$$ for this but I have very limited choice around here.....

Onward........

Did you buy the parts and bring them to him? A good motor assemble-ing with dyno time can easily be 5k and up. Thats them just putting together what you brought them. it takes alot of time to be sure all the clearences are correct. if your using a reputable motor builder paying for his experiance and expertise comes at a premium, but it's worth it.


What compression ratio did you end up with? if you want to go more than 5psi in the future nows the time to make room (in the combustion chamber) but even 5psi makes lots of smiles.....enjoy it.

Thanks......most of the parts they brought in, we were not sure what we needed at the start.....I totally agree, you get what you pay for, you are very close with the cost for the build....

We finished up at 8.66 for compression, according to the shop that programed the ECM, that is right in the ballpark for what we wanted.....

Start with about 4lbs of boost and go from there.

Can't, I have a 5lb pulley that came with the "pre-owned" Procharger....

Would there be a big difference between 4 and 5 as an initial set-up..?

Different sized pulleys will make more or less boost pressure depending on flow numbers and C.I. of the engine. No way to really tell exactly what boost pressures you are going to pull just because of the pulley size. You can esimate based on what the pulley does/did on another engine.

This is all new territory for me, I have tried to do my homework and get my ducks in a row but we all know anything to do with boating is not straight forward...

With the current set-up we are "aiming" for 5lbs and that is what the ECM was set for, more or less....so I guess it will just be a matter of playing with fuel pressure and timing............??

fuel pressure, injector size, timing + pulley diameter if you need to lower boost . .which might require a different length belt.

leave all this to your dyno man, who needs to know. . . .

Mario L.