Multiple port cylinder for crankchamber precompression type two stroke engines

摘要

A cylinder for crankchamber precompression type two stroke engines includes three pairs of main scavenging ports which are symmetrical with respect to a longitudinal plane passing through the centers of the intake and exhaust ports and containing the longitudinal center line of the cylinder. A pair of auxiliary scavenging ports are provided at the opposite sides of the longitudinal plane in such a manner that in a horizontal cross-section the flows from the auxiliary ports do not intersect with the flows from the main ports. Further, the auxiliary scavenging ports are directed further upwardly than the main ports.