Compression numbers #
 

I just did a compression check on my 911 2.7 L -1975 with 50 000 Km since Top End Rebuild. Can anyone tell me what a normal compression reading would be.

Here are my results
cyl# - compression (psi)

1 - 157
2 - 158
3 - 148
4 - 158
5 - 150
6 - 140

Thanks,

There really is no "normal" what you are looking for is no more than a 10% deviation between the cylinders. Was the engine warm with the throttle open? If not retest. If so I would investigate why cylinder 6 is reading low. Maybe just piece of carbon caught in the valve or need a valve adjustment. Check and retest.