speed pro hypereutec.

[ezrollin]

Anyone using the Speed Pro hypers. [$28.69] at Summit ? Think they would be worry free at say 12 lbs boost ? They come dished but I have tired to compute cr with 3500 heads yet.

[El_Diablo]

yes, they should be fine, cast pistons will work at 12psi.... hell, ive seen cast pistons in other engines last to over 25psi but its all in the tuning, get any detonation and say goodbye to your bottom end

[ezrollin]

I'll have to compute the cr using 3500 heads. Wonder what a 3.4 / 3500 will produce with 12 psi ?.

[El_Diablo]

more than enough to break a 4t4xE would be my guess.....

what car is this for?

[ezrollin]

It's for an s10 blazer 2wd and I'm looking for an 8.5 rearend.

[ForcedFirebird]

I'll have to compute the cr using 3500 heads. Wonder what a 3.4 / 3500 will produce with 12 psi ?.

Your using 3400 pistons? With 3.4 pistons 3500 heads are 11:5:1 SCR using the 3500 head gaskets. IIRC off the top of my head 3400 pistons and 3500 heads with 3500 gaskets was 9.1:1 - check the CR Calculator.

[ezrollin]

11.5:1 with dished pistons ?

[ForcedFirebird]

11.5:1 with dished pistons ?

The 3.4 and 3400 pistons are both dished. 3.4 dishes are just smaller.

[ezrollin]

O.K. Just looked them up 3400 [ .275 x 3.180 ] 3.4 [ .087 x 2.765] 9.1:1 would be great.

[ForcedFirebird]

O.K. Just looked them up 3400 [ .275 x 3.180 ] 3.4 [ .087 x 2.765] 9.1:1 would be great.

http://wiki.60degreev6.com/index.php...tio_Calculator