Compression Test Results and Questions

[jeff8877]

Hi guys,

I read through the other recent thread on a compression test but still have a few questions for you...

Dry test performed with engine cold, carb off car and rag over intake, 5 to 6 cycles for each cylinder, all spark plugs out. Don't know for sure mileage on engine but worst case is 95k but may have been rebuilt at some point but not sure.

Results...105 110 108 105 110 110 112 108

This is the 4V motor so trying to decide if I "need" to rebuild or if it is good enough to just clean up as car will only be used for shows/Sunday drives.

The original specs for this motor were a 9.0 to 1 compression ratio and I think my results are in the 7 to 7.5 range if I divide by 14.7??

Input much appreciated!

Jeff

 

[Don C]

Altitude will affect the readings, and the 14.7 psi needs to be adjusted to your altitude and barometric pressure.

 

[marks73]

If you are anywhere near sea level I'd say it's time for a internal rebuild.

 

[hyena429]

Ya...She getting a little tired inside it sounds like...Mine was down even more than that...did not smoke or anything...but started runing ruff...my compression check was 95 up too 100ish...my rings where toast....Some one did not cross hatch my cilinder walls.....And cam was worn down a bit "I think due too a rag i found in the oil galley" You never know what is going on till you take it apart...i drove this car for 15 years with out knowing what was going on inside the motor...It ran fine and acted fine...But it was not..lol

 

[marks73]

Always best to rebuild before the failure.

 

[jeff8877]

Thanks guys...sounds like I will have it rebuilt while it is out.

Jeff

Always best to rebuild before the failure.

 

[MotoArts]

Dry test performed ... and rag over intake...

:s Uhhh... why the rag over intake?

Never heard of that one.

Try the test again without the rag. Sucker needs to get air from somewhere...