Compression

[JOhnH]

I just had my first oil change on my rebuilt O360. The engine has about 13 hours and I asked for a compression leak down test.
Results: 78, 76, 76, 76/80

Is this acceptable for a "new" engine?
Thanks,

 

[tonycondon]

seems pretty good to me.

 

[Dan Thomas]

I just had my first oil change on my rebuilt O360. The engine has about 13 hours and I asked for a compression leak down test.
Results: 78, 76, 76, 76/80

Is this acceptable for a "new" engine?
Thanks,

The numbers aren't out of reason but we often see them higher than that on new engines. They may come up some by 50 hours, but if you don't run it fairly hard and get full ring seating they might not improve. And it might use a bit more oil than it should.

This is assuming the leakage is past the rings (listen for the air at the oil filler). If the valves are leaking you'd hear it at the intake or exhaust.

Numbers would be a bit lower if the old cylinders were just honed and new rings installed. Are these new cylinders or reconditioned?

Dan

 

[JOhnH]

Thanks for the reassurance.

T
Numbers would be a bit lower if the old cylinders were just honed and new rings installed. Are these new cylinders or reconditioned?

Dan

New Titan Nickel cylinders.

 

[Witmo]

Those numbers are fine. Now go out and fly!

 

[JOhnH]

Those numbers are fine. Now go out and fly!

We are taking it to N.C. (MQI) tomorrow.