Abstract: An engine piston and ring assembly providing improved oil control and where applicable sealing of scavenging air. In a preferred embodiment applicable to two-cycle port scavenged diesel engines and similar applications, the piston is provided with dual oil ring grooves near its open end, which is free from drain openings through the wall in the vicinity of the ring grooves to the oil cooled hollow interior of the piston. Drainage of lubricating oil scraped from the cylinder walls by the rings is provided instead by scalloped recesses in the lower wall surface extending from the open end of the piston to the nearest ring groove. The arrangement reduces leakage of scavenging air from the inlet ports to the engine crankcase as well as the occasional flooding of the piston rings with the cooling oil from the piston interior.