Patent ID: 6668770
Filing Date: 2003-12-30
Classification: F02B,F02F

Abstract:
An arrangement in a crankcase scavenged two-stroke internal combustion engine, said arrangement comprising:a two-stroke internal combustion engine having a cylinder, a piston arranged for reciprocation in said cylinder, a crankcase, and a crank mechanism coupled to said piston via a connecting rod; a piston ported air passage, with length Lai, arranged between a scavenging air inlet and a scavenging port via a connecting duct, and said scavenging air inlet equipped with a restriction valve controlled by at least one engine parameter; a transfer duct, with length Ls, extending from said scavenging port to said crankcase, said transfer duct fluidly interconnectable with said piston ported air passage via a flow path located in said piston; and a length, Li, of an engine air passage measured between an engine air inlet and an air-fuel mixture port is less than one and one-half times the total length of the piston ported air passage, Lai, plus the length of the transfer duct, Ls.