Denny, before you condemn the rings, why don't you do dry and wet compression checks? The outcome will give you better insight into what is going on with your engine. An increase of 20 PSI or so wet is more or less typical, but a greater increase than that indicates ring leakage. If you have the setup for a cylinder leakage test, ring leakage will show up as hissing/rushing noise in the crankcase. Twenty percent or less leakage typically has been considered acceptable, but less is better; 10% or less is pretty common in a good engine. From 20% to 30%, you usually don't notice any difference in engine performance, but above 30% its your choice. I have seen engines running with normal compression (115-130 PSI dry) and 40-45% cylinder/crankcase leakage, dry, with no perceptable change in performance, although these were typically light-duty vehicles. I don't remember wet compression numbers for any of these engines, but they didn't get anything more than "tune-up" work at the time.
Just for clarification, "dry" in these tests means the tests are done after normal operation, and no oil added to the cylinder for the tests. "Wet" means an ounce or so (or 2-3 squirts from a pump oiler) of oil, added to the cylinder and the engine turned a couple of turns before doing the test.
As for the valve guide seals, when they first came on the market, on V-8 engines, you had to cut the outside diameter of the guide in order to install the seal. I don't remember on the 6-cyl engines, but I think the same operation applied. They were Perfect Circle then, too.
Harvester
