Lowest compression value for good running 8.6 ratio motor?

[todd230]

Just wondering what the lowest values some of you experienced builders have seen in tired, but still decent running motors? Not really interested in a compression test tutorial (no offense), just data - what have you seen regardless of tester conditions, equipment, etc..

[mreid]

The bigger issue is consistency cylinder to cylinder, however I would want to see greater than 100 psi with all cylinders within 10% of each other

[E Sully]

125-130lbs

[Walt Fricke]

I favor the leakdown test, but if doing a compression test it is easy to do a leakdown at the same time. That will tell you where air is leaking out (intake, exhaust, rings, or all three) as well as how much total. And will allow good cylinder to cylinder comparisons. 10 or 12% (maybe a bit more) might be typical in a worn but still decently running motor, especially if the major leakage is from the rings.