Small high speed two=stroke engine cylinder - has at least three simultaneously opening exhaust ports and off-centre ports closing before BDC

摘要

The cylinder is intended for a two-stroke combustion engine, partic. for a small high-speed engine with reversing scavenging flow, having a flat-top piston whose piston rings and skirt pass at least one scavenging port (12) and exhaust ports (8) in the cylinder wall with a longitudinally extending dam between the ports (8). There are at least three exhaust ports whose upper boundaries are cleared simultaneously by the piston top. These ports are sepd. by longitudinal dams as bearing surfaces for the piston. The non-central ports (8) do not fully extend to the BDC level of the piston top.