Cheap way for HP on Gen2 ???!!

[DirtRacer]

After looking a CR calculator... Using a 3.1 crank on a 2.8 MPFI with steal head gasket will raise Cr to 10.1 from 8.9.

Or we can use Rods and pistons fropm a 2.8 MPFI with a 3.1 MPFI with the same gaskets,...

Is there any mods. to do to build this set up??

With that set up what would be the compression with a comp. gauge (in psi..)


Thanks..

[SappySE107]

Too bad you will blow the heads off the motor if you use 2.8 pistons on a 3.1 crank. Maybe the iron head piston versions would net you more compression?

[DirtRacer]

??

Why the heads would blow up?? There is only 5 cc difference on both pistons.

Are the pistons from 2.8 (alu head) are much higher??

[Guest]

Stroke....

The 2.8 pistons will come out of the block if used with a 3.1 crank, by almost exactly .15".

[DirtRacer]

0.150 mil... wow!! Way too much...

2.8 pistons from RWD would bring me over 13 even 14 to 1 i believe... Way too much either...

But can we have the top of the 2.8 MPFI piston machined.?? Maybe cutting the extra .150 that seem to be just the edge of the top of the pistons!!
Maybe that would be the same as using the 2.8 piston from RWD motor.
isn't it??

Seem's difficult to find a way to get HP from little mod. that can be seen from inspectors at the track!!!

[montess408]

the best thing to do is get a set of pistons made for a 3.1 camaro they will give you higher comperssion and nobody will be abel to tell the diff. if you dont say anything !!

[ForcedFirebird]

The crank has to match the pistons you are using (2.8/2.8, 3.1/3.1) because of wristpin heights so GM could use the same rods, are you not allowed to stroke to 3.1?

I don't know if you will be able to get that much off the piston without weakening them. I looked into increasing the dish to lower compression and the ring lands would be too thin.

[sil]

if your not running a turbo you could take it off, prolly even have more CR over using 3.1 pistons

cant you use gen 3 heads, dont the 3100 and 3400 have a little bit of piston sticking out top anyways?

[IsaacHayes]

I don't know the stipulations but yeah a gen3 top end or full 3x00 motor would be nice. What about an UDP?

[DirtRacer]

Have to use Gen 2 heads and upper manifold.

By using 3100 pistons and rods with the 3.1 gen2 block.. would the CR be higher??

If so, by how many??

[Guest]

9.5:1, same as the 3100. You have to use a 3.1 or 3100 (even 3400) crank to have the proper 3.31" stroke.