Two cycle internal combustion engine with unidirectional flow scavenging

摘要

In a two cycle internal combustion engine with uni-directional flow scavenging wherein a piston is disposed in a cylinder so as to be movable between top and bottom dead center end positions, the cylinder has fresh air inlet passages which are so arranged that their bottom walls are disposed below the piston top edge when the piston is in its bottom dead center position so that part of the piston top land is directly exposed to the fresh air flow through the air inlet passages and oil discharge bores extend from the air inlet passages and are in communication with the oil circulating system for the removal of oil wiped off the cylinder wall and collected in the inlet passages.