How to measure compression

[Kuma]

Is there a way of getting an compression reading with a compression gauge? Does the decomp have any effect on the reading or do you just plug in the gauge and crank it over?

[peterock]

hold the throttle wide open and crank it over

[cannondale27]

Yup 80-120psi is what you should get.That takes the decomp into the result.Without decomp it would be well over 200psi.

[Kuma]

QUOTE (cannondale27 @ Feb 26 2009, 08:47 PM) <{POST_SNAPBACK}>

Yup 80-120psi is what you should get.That takes the decomp into the result.Without decomp it would be well over 200psi.

ya, I thought the decomp could have an effect on the reading.
in a perfect world if I have 12.5:1 then I should see about 183psi, is there a correction factor that can be applied taking the decomp into consideration?

[cannondale27]

Would depend on you valveclearance,Timing and probably other factors.80-120psi is accurate enough to tell if everything is right.

[Kuma]

QUOTE (cannondale27 @ Feb 27 2009, 11:21 AM) <{POST_SNAPBACK}>

Would depend on you valveclearance,Timing and probably other factors.80-120psi is accurate enough to tell if everything is right.

Thanks Steve