Piston ring installation is one of several critical operations performed during an engine overhaul or rebuild. When installing the rings on the pistons, damage can be caused without the operator’s knowledge that will cause early engine failure.

It is important to use proper ring installation tools and to exercise care when opening the ring to put it on the piston. If the points of the ring are not kept on line with each other the ring will be bent or otherwise distorted. In order to perform properly, a compression ring must seal not only an its O.D. face but on its side faces. If the ring is bent it offers a leakage path for both blow-by and oil.

The photograph shows a ring that was bent during installation and ran in the engine. Note the disruption in side wear pattern.

(P48)