Patent ID: 7082910
Filing Date: 2006-08-01
Classification: F02B,F02F

Abstract:
1. A crankcase scavenged two-stroke internal combustion engine comprising: a piston arranged within a cylinder and configured for reciprocating motion therein; a piston ported air passage arranged between an air inlet and an upper part of each of a plurality of transfer ducts; said air inlet being equipped with a restriction valve controlled by at least one engine parameter and said air inlet extends, via at least one connecting duct, to at least one connecting port in a cylinder wall of the engine; each of said connecting ports being positioned so that when said piston is in a top dead center orientation, each connecting port is connected with a flow path configured upon the piston and that extends to the upper part of the plurality of transfer ducts; and each flow path in the piston and cylinder is predominantly arranged in essentially a lateral direction with respect to said cylinder as each connecting port and an adjacent scavenging port are arranged sideways in relation to each other along the periphery of said cylinder wall as an associated transfer duct extends essentially in the lateral direction away from the associated scavenging port thereby establishing an essentially tangential relationship between the flow path and a circumference of said cylinder wall.