Compression #'s

[QDRHRSE]

What kind of compression #'s do you guys get when you run a compression test....that is, if have have done one? List heads and cam too please. I'm seeing 145 with AFR 185's and an F Cam. Anybody else? Is this low?

 

[tmoss]

Mine averaged 145 also with my stock cam (with sloppy 190k chain) and stock heads. Haven't retested since the P head install. My stock cam had valve events VERY close to the Crower 15510 cam.

 

[HISSIN50]

im one to believe it is a bit like two guys comparing dyno runs (even from the same dyno): the relative numbers you get are what matters - not absolute numbers. there are enough variances in gauges and methods (motor warm, at WOT, etc) to create deviation. as long as they are all close, i would not sweat it.

now if i totally missed the point of your posting - my bad.

good luck.

 

[QDRHRSE]

Hissin-

No. You got it. It looked low and it got me thinking because the car is running like crap and I can't figure out why. Your absolutely right about everybody being different but I just wanted to see what the spread was like.

 

[v8only]

last time I ran a check on a healthy stock 5.0, I got around 150 all the way around, your #'s sound about right.

 

[fost9508]

What about compression from cylinder to cylinder, when I have done a compression test all the cylinders get a little bit diff numbers. What is the rule of thumb when review the compression test results. i.e. all the numbers should be +- 10 psi from the highest cylinder reading....????

thanks,

 

[87'GTstang]

What about compression from cylinder to cylinder, when I have done a compression test all the cylinders get a little bit diff numbers. What is the rule of thumb when review the compression test results. i.e. all the numbers should be +- 10 psi from the highest cylinder reading....????

thanks,

+/- 10 percent