[stevecollins]

I have a 1991 Pace Arrow 37’ motorhome on a P30 Chassis. The engine is a stock 454 rated at 230 HP and about 300-350 Ft Lb Torque. It has the throttle body injection system. Not enough “umph” to pull itself up a good size hill, let alone with my enclosed 22’ Trailer attached (for my Sandrail and Honda Pilot) at about 5,000 to 6,000 Lbs. I also have a serious concern for overheating with the doghouse and low circulation. It has the normal clutch fan and an electric pusher fan, plus a water spray mist system in front of the radiator that I added.

I just bought a 454 Chev Truck Motor to rebuild into a power house for this motorhome. I need to know just what do I need to do for this project. I have only built my Corvair engine for my sandrail, and don’t know much about these engines. I will have a machine shop and a friend help with the engine build, but I like to know just what is going on.

I would like to pick up a book on Big Block engines that will help guide me through this project, but don’t know what is a good one. Any suggestions?

DoubleVision has told me to increase the compression to 9.5:1 and to add an RV cam, such as the comp 268H series, add an Edelbrock performer intake, a K&N air filter, a brass terminal cap, spiral core spark plug wires, headers and a decent exhaust system with crossover pipe to give it more torque. Also Siggy_Freud suggested MSD box. I really appreciate these suggestions.

Since I am going to build the motor, I plan on have the block align bored, vated and everything balanced.

Now what about the crank, rods, pistons, heads and other stuff? Where will I get the bang for the buck?

If I add headers with the stock heads, will I have problems with the spark plugs (servicing)?

If I get heads which should I get? Angle/straight plugs? Oval or Rectangle ports? What CC chambers, What is the optimum Valve size? Cast Iron or Aluminum?

What about the crank for the extra HP and Torque, the Rods anything else? Oh yes what about “stroking” this baby.

And then the pistons. Domed, flat top, etc.

The cam, roller rockers, roller timing, all the other trick things I have heard of but don’t know much about?

Am I going to have problems with the computer? Where is the computer and what does it look like anyway? Any suggestions on Chips?

Oh yes, and after all this information I would like it to pass “emissions”.

Enough challenges? I really appreciate any help you can provide. Thanks Steve

[tresi]

Don't get the block line bored unless there is a need to. You'll just cause issue that will need to be delt with later. If you make anything other than mild changes you'll have to find someone who can burn you a custom chip or get the stuff to do it yourself.

9 1/2:1 will be too much compression for a motor home unless you plan on buying 93 octane every tank. 8 1/2:1 will be easier to run run on 87 octane. When you lug a motor with extra weight it will be more prone to detonate. If you have the room under the dog house I'd go with a 502 rather than the 454. If you want to keep your block I would go with the stroker kit. I think that you should be able to fool the stock computer to run with 50 extra cubic inches by jacking up the fuel pressure until the computer and engine are happy or get larger injectors for your throttle body.
I don't like to run headers with such heavy vehicles. The headers don't tend to last very long. If you find some really thick wall headers or have a set made of stainless steel that would be a different story but an expensive story.
Stick with oval port heads. You're going to need a flat top or dished pistons to get the compression right. As for the cam stick with specs like this at .050" 204 intake duration, 204 to 212 exhuast duration. The computer works best with wide lobe seperation angles so go with 112 degree lobe seperation. 108 lobe seperation would make more torque but the computer won't like it.

[stepside454]

tresi has you covered

[4 Jaw Chuck]

For the money and the hassle of trying to custom fit headers to fit I would have a look at this turbo system from Banks Engineering. Not much can beat a power increase and a mileage increase at the same time, think of it as paying for itself in fuel economy.

Bolts right up too!