HELP WITH COMPRESSION RESULTS!

[rei-04]

ok I just finished doing a compression test on my 120k mile 5.0. Here is the results:

1) 90/115/130/135/140/140/140/140

2) 110/115/125/130/138/138/138/138

3) 105/120/130/130/132/132/132/136/140/140

4) 110/123/130/132/132/134/134/134

5) 120/150/150/150 etc

6) 105/115/125/130/130/135/140/140

7) 90/115/125/130/130/135/140/140

8) 80/125/130/130/130/130/130/130

How are my results? Also everytime I pulled the adapter out of the spark plug slot it had a little bit of engine oil on it. Is this something that I need to fix now, or will I be able to go awhile w/out fixing. I really don't have the funds for it.

Also I have my spark plugs gapped at .44. I was thinking about dropping them down to .38 or .40 Would this be better for performance? Here are my mods:

kirban fpr
msd high ignition coil and cap n rotor
mass air meter calibrated for 24# injectors
bbk 65mm t/b
cobra upper n lower intake
smog pump bypassed (shorter belt)
Mac L/T headers
modified x-pipe 2.5 (no cats)
flows
4:10 gears

thanks for the help guys

 

[Boss 351]

130 to 150 on different readings??? Is your tool working?

 

[rei-04]

130 to 150 on different readings??? Is your tool working?

I think my compression tester is working just fine, I just bought it 2 days ago, why do you ask?

 

[jerry beach]

Was the engine hot and did you wire the throttle wide open? All cylinders should read within 10% of one another. It looks like you have a 15% difference or so. Does it idle smooth? If so the motor is prolly fine. Try pulling the codes and doing the throttle blip at the end. The computer will run a cylinder balance test by pulling the injectors one at a time and recording rpm. If it passes this test, all is well. Otherwise the puter will tell you which cylinder(s) didnt pass and you can compare it with your compression test. If you dont know how to pull the codes then do a search here on Jrichker, he has links to it. Or buy a simple Haynes manual and it will walk you through the self diagnostics.

 

[HISSIN50]

are you showing us each increment of increase during each cylinder's test? i think so, and that is why it goes from 90-150, for example.
Jerry is right on. i would have done a dry and then wet test (future reference).
stangs have low tension rings - some oil bypass is normal. too much is not. again, wet and dry test would help with that (we need numbers since we are not there with you).
good luck.

 

[rei-04]

thanks for the info guys

umm you said you need #'s not sure what you mean, I posted each stroke with compression rate.

also what do you mean by wet and dry test? Sorry my first time doing it.

again thanks for the info.

 

[HISSIN50]

thanks for the info guys

umm you said you need #'s not sure what you mean, I posted each stroke with compression rate.

also what do you mean by wet and dry test? Sorry my first time doing it.

again thanks for the info.

wet test is where you simply check the compression. wet test involves putting a very small amount of oil in the spark plug hole (too much oil could hydrolock the cylinder so be careful) and testing again. the oil will seal weak rings; if the numbers go way up from the dry to wet test, that suggests the rings are allowing some blowby.

good luck.