Compression Test Results ?

  • Thread starter Thread starter Deleted member 87397
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Deleted member 87397

Well I'm dying to get my top end kit put on, but I thought I'd do a compression test today to see what shape my rings are in. Engine is 1986 stock internals with 58K on the clock.

All cylinders were between 150 and 160.

I did the oil squirt test only on a couple that I've suspected lately of having problems and the reading went up 15-20 max which I thought was not too terrible, but I could be wrong.

My main question is this: The book says "compression should build quickly. If the reading after the first compression is low and then compression builds slowly on successive compressions then worn rings are likely" I want to know what is considered a low reading on the first compression? All cylinders I tested jumped to about 100 psi on the first compression and took about 3-4 additional strokes to reach max. So, does this sound normal or does is sound like my rings are worn.
 
I always thought that as long as the cylinders were all within 15% of each other, then they are good results. I too would be interested in seeing what exactly would be a "low" reading.