Patent ID: 6520128
Filing Date: 2003-02-18
Classification: F01L,F02B

Abstract:
A method of operating a two-stroke engine comprising:moving a piston in a bore of a cylinder toward, through and away from a top dead center position at a combustion end of the cylinder; maintaining a piston valve mounted for sliding motion in the piston closed by a greater pressure on a forward side of the piston as the piston moves toward the top dead center position; receiving cycle air through a cycle air intake in an opposite end of the cylinder proximate a rear side of the piston; moving the piston in the bore of the cylinder toward a bottom dead center position at the opposite end of the cylinder; receiving cycle air into the bore of the cylinder through the cycle air intake in the combustion end of the cylinder at a forward side of the piston; simultaneously compressing the cycle air proximate a rear side of the piston in the opposite end of the cylinder; opening the piston valve in response to a greater pressure on the rear side of the piston as the piston moves toward the bottom dead center position; maintaining the piston valve open in response to the greater pressure on the rear side of the piston as the piston moves through and away from the bottom dead center position to supply additional cycle air within the bore of the cylinder on the forward side of the piston, thereby improving the scavenging of combusted air from the cylinder through the exhaust valve and providing additional cycle air for compression and combustion; and closing the piston valve in response to a greater pressure on the forward side of the piston as the piston moves toward the top dead center position.