Okay guys so im going to be running a P600B Procharger kit on my LT1 with the 8lb pulley. I am going to build a motor for it. I am going with forged pistons, rods, and freshing up the stock crank. Having a 8.5-9.0 shortblock without h/c is it going to be a complete dog? If so how much of cam would i need to help make up for the lack on compression and same for heads how radical do i need to go?

Im trying to do this on a budget and my engine guy says if im going to build the engine on a low compression and dont do h/c i should either run the stock compression or crank up the boost to help even it out.

Any suggestions???

Matt.

 

First of all, an LT1 with 8 lbs. boost is not going to be a "complete dog" just because the compression was lowered. Its a good move because it will be more safe.

As far as the heads/cam, it really depends on your budget. If you have the extra funds, it would definitely make a nice difference to have, because the stock heads and cam are definitely a restriction when running boost. The cam would not need to be too radical at all. Most cars with boost do not have or need to run radical cams to make good power. Just something to wake it up a little. I say decide what you want to do from the start and do it all at once while you have the motor out. It is much easier to do it right the first time then to put everything back together and then decide you want to put better heads on or something.

What are your power goals? If your lowering the compression and building the motor right, why not turn the boost up to 10-12 lbs. anyways?...

 

Do you already own the 600b? I say skip it and got to an S or T trim. You can probably make more power off a built heads cam car.

My built 383 with Le2 heads and a 232/236 cam made 411RWHP thru and auto and 12 bolt and the compression was 9.8:1.

if your gonna built it and only run 8psi built it around 9.0:1. alot of guys running 15lbs have 9.0:1 compression.

Im now building mine to 8.8:1...15-20lbs

Jay

 

It won't be a "dog" but the cam should be selected carefully. A properly selected cam for that combo will not be "radical" at all. In fact, it shoud have a very short intake duration, a wide LSA, and an exhaust lobe at least 10-12 degrees larger than the intake.

Rich

 

Ive seen a video of a forged 355 with a small cam put down 438rwhp. That is realisticly my goal 425-450 as i want it to be streetable and not overdone. I plan on doing h/c down the road but just not going to be able to swing it all at once. If anything ill build it with a cam so i don't have to tear it down. Heads are easier to pull down the road. Should i build it around 9.0:1 and still have enough jam and still be safe if i do heads down the road?

 

9:1 is good unless you plan on high boost (>10-12psi).

Rich

 

Well im thinking that ill definetly stick with 9:1 comp just to save and still make some good power on the street. How much power would you guys think it would put down without h/c and then with?