Abstract: A piston assembly is described including a connecting rod and a piston head secured to the connecting rod and in operational communication with the connecting rod. The piston head has a circumferential groove extending inwardly from an exterior surface of the piston head. The piston head further has a compression mechanism aperture disposed proximate the groove. An oil ring expander is disposed generally within the groove. The expander includes a gap between a first expander end and a second expander end. The gap is proximate the compression mechanism aperture. At least one lever arm is in mechanical communication with the connecting rod. The at least one lever arm has a tab disposed between the first expander end and the second expander end.

Abstract: A piston assembly is described including a connecting rod and a piston head secured to the connecting rod and in operational communication with the connecting rod. The piston head has a circumferential groove extending inwardly from an exterior surface of the piston head. The piston head further has a compression mechanism aperture disposed proximate the groove. An oil ring expander is disposed generally within the groove. The expander includes a gap between a first expander end and a second expander end. The gap is proximate the compression mechanism aperture. At least one lever arm is in mechanical communication with the connecting rod. The at least one lever arm has a tab disposed between the first expander end and the second expander end.

Abstract: A variable oil ring compression mechanism provides for real-time cyclic variation of piston ring tension in an operating internal combustion engine. A cam is situated in the gap of a piston oil control ring, the cam affixed to a shaft secured to a pivot plate positioned within the body of the piston, wherein the pivot plate is adapted to oscillate in a follower-style rocking motion responsive to the rotary movement of a connecting rod boss positioned in close proximity with the plate. In a preferred form, the cam is situated between ends of an expander ring positioned between oil scrapper rails in the bottom groove of the piston.