Originally posted by 30-A Rider
I am no engine building expert by any means with regards to autos, but have rebuilt many many single cylinder motorcycle engines.

Reason I say this is becuase on may occasions compression will be up to spec., if not even higher on an engine that needs a rebuild. This was especially apprarnet on big bore 600cc single cylinder 4 strokes. The rings would be shot, and the top of the piston would look like it was shot with a bb gun 100 times. The top front and rear of the piston at the intake and exhaust post would present as if they were taken to a stone grinding wheel; and the compression would still be up to spec.

IMO you can definately have tired cylinders and rings and still show adequate compression. Just my .02
auto. motors dont work that way.