331 Motor Build questions...

[caseywan]

Wasn't sure if this should go in Tech or Talk, so move it if needs be...

Anyway, I started a thread a little while back about adding a Kenne Bell 2.2, porting my X-heads, and getting a water/methanol injection kit and having 450+ rwhp on my GT40 block in the sig below, and I decided to take everyone's advice and not split nearly new block in half and go with stronger block. So here is what I'm thinking.

I found a local deal on a 331 shortblock R302 block bored .40 over with 4340 Eagle rods forged JE pistons and a Scat 4340 crank.

So here are my questions. I was thinking about getting that shortblock and getting my X-heads ported by thumper, and my compression would be 9.0:1 with those heads. First off, would I choke a 331 with a Kenne Bell using ported X-heads, and second would that compression ratio be optimal for 14-16 psi with the KB? If I keep the X-heads, a couple years down the road I would probably get some AFR 205's or something better when I can afford them.

Also, how would the E-303 cam do with this setup? I am thinking I would want to go custom or get a Comp cam.

Last questions, what size injectors would I want? I will be going with either 14 or 16 psi, I was thinking 42# injectors, but that might be too small.

Any input would be awesome, Thanks!

 

[86bluecobra]

I think 9 to 1 maybe a little high for 14lbs of boost. maybe try a 8 to 1 or 8.5 to 1

 

[FastDriver]

Dude, if you're going to spend the coin to get the R302 and a 2.2KB, don't skimp on the cam.... It is probably the most important decision you'll make. That said, go for a custom and tell you cam guy to get the cam that will work with your planned combo so that future upgrades won't take you away from the cam that you get.

Chris

 

[FastDriver]

Oh yeah.... don't go over 8.5:1 if you're going to push more than 12 psi... I'd say you'll probably be ok at 15 psi, but don't skimp on the tune... The last thing you want to do is save $500 on a dyno tune just to trash a few grand worth of parts.

Chris

 

[caseywan]

Yeah, I was pretty much planning on getting a custom cam, just wanted to know what the general consensus would be, although I could have guessed.

Oh yeah.... don't go over 8.5:1 if you're going to push more than 12 psi... I'd say you'll probably be ok at 15 psi, but don't skimp on the tune... The last thing you want to do is save $500 on a dyno tune just to trash a few grand worth of parts.

Chris

So you think I would be ok 9.0:1 pushing 15psi? I don plan on getting a good tune.

 

[caseywan]

Any other input would be awesome...

I actually just found out the shortblock I am looking at buying is a 333, not 331. Not that it really makes much difference.