| abstract |
A two-stroke cycle gasoline engine including at least one two-stroke cycle power cylinder-piston assembly incorporating uniflow scavenging and two horizontally opposed pistons and two crankcases to perform crankcase compression, and at least one scavenging pump cylinder-piston assembly of the reciprocating type, wherein the power assembly has main and additional scavenging ports; the pump assembly has a first delivery port which supplies scavenging mixture to one of the crankcases of the power assembly and a second delivery port which supplies scavenging mixture directly to the additional scavenging port, the main scavenging port being supplied with scavenging mixture from the crankcases, wherein the top dead center of the pump assembly is, as viewed in the crank angle diagram, between the bottom dead center and the main scavenging port closing phase point of the power assembly, and wherein a means is provided so as to interrupt the supply of scavenging mixture from the first delivery port of the pump assembly to the one crankcase from a phase point located between the main scavenging port opening phase point and the bottom dead center of the power assembly to at least the top dead center of the pump cylinder-piston assembly. |