about skim from the head

[some man]

I have jeep wj 4.0 1999. How much(max) can I safely skim from the head?

[Russ Pottenger]

Without hesitation I've removed up to .040

How small you trying to get your combustion chambers?

[some man]

thank you very much!


In general the purpose of this is approximately CR 10-10.5. How much skim from the head to do this (how small must be combustion chambers), I don't know, haven't touched a calculator. Maybe someone did something similar and there are already calculations?

[Russ Pottenger]

For every .005 to .006 you'll lose about 1 cc.

Am I correct to assume that your engine is totally stock?
If so you realize you're not going to be able to run pump gas?

[some man]

Yes stock.

Sorry for my English, what do you mean " to run pump gas" ?

( If you mean octane, now i run on 93 octane. It should be enough that no detonation. Then I plan to install a custom engine control unit. )