05silgto

Stock ls2 engine with 88k miles, 600whp Procharged
Results- This was a cold compression test near sea level
212 #8 #7 208
173 #6 #5 210
205 #4 #3 203
194 #2 #1 200
18.4% diff. between #8 and #6
I also did a wet compression test on #6 and got the same results. Is this a bad sign? My air compressor only goes up to 150psi so I can't do a leakdown test.
Obviously it's not the piston ring and it's probably not the head gasket, what else could be the cause besides intake or exhaust valves?

RonSSNova

iTrader: (3)

100 psi should be fine for leak down test. In fact my OTC tester uses just 100 psi.

Id do it warm btw.

05silgto

Thanks for you input. I plan on doing it warm once I got everything back together. I think I will just measure #8, #6 and maybe #2 to measure the difference.
I'm a bit of a noob with all this and after a quick search a leakdown test turns out to be a bit different than what I thought, I would have to borrow one from a friend.

stevieturbo

Is there a reason for doing the test in the first place ?

And it could be rings or piston related.

05silgto

I did the test again with Teflon tape on the tool's threads after I realized the two spark plug holes with the lowest compression were the threads I just repaired. The tool has very few threads so it was only contacting the outside threads that were slightly damaged. Doing the test again I ended up with 200psi for that cylinder. So all is good. There was no reason for doing the test other than just trying to gauge the health of the engine while changing the plugs.