Max compression for pump gas?

[SLORYDER]

Yeah and does shaving .040" off the stock head normally cause you to have to run it?

 

thanks

[wacko2000]

I believe guys shave the head to bump there compression.

I would do a compression test, so there arent any guessing games.

I believe over 155-160 you need race fuel.

[TwistedSheeRida]

.040 is a lot to be shaving off of the stock head, i would stick with .030. The cut off for race fuel is somwhere around 170 psi.

[blowit]

 

I believe over 155-160 you need race fuel.

 

 

Again, it is very important not to associate pumping compression numbers with actual comp ratio. Pumping pressures can vary greatly depending on engine parameters and atmosphere.

[SLORYDER]

Again, it is very important not to associate pumping compression numbers with actual comp ratio. Pumping pressures can vary greatly depending on engine parameters and atmosphere.

OK man.

Generally speaking, what is a good cutoff, kicking compression wiseto start using 50/50.

And how much do you recommend shaving the stock head/

[AKheathen]

unless you have changed what you are planning to do with your motor, i would switch at 145-150psi. keep in mind, tah this is knowing your motor. some can go 180+ on 93, setup right. i pulled 180 with 90oct. now, for the head, rule of thumb, is keep it under .030" shave, but you should measure squish first. most of the time, more than that will call for cutting the chamber to fix the squish.