Patent ID: 6019074
Filing Date: 2000-02-01
Classification: F02B

Abstract:
A two cycle internal combustion engine having a cylinder block defining at least two cylinder bores having parallel side by side axes lying in a common plane, a cylinder head closing one end of said cylinder bores, a piston reciprocating in each of said cylinder bores, an exhaust port formed in the said cylinder bores at the inlet end of a respective exhaust passage formed in said cylinder block and opened and closed by the reciprocation of the respective piston, said exhaust ports all lying on the same side of said common plane, a pair of circumferentially spaced main scavenge ports formed in each of said cylinder bores on opposite sides of said exhaust port and served by respective main scavenge passages configured so as to create a scavenging air flow that moves axially along the respective cylinder bore toward said cylinder head, across said respective cylinder bore and down said cylinder bore toward the respective exhaust port, and each of said cylinder bores having an supplemental scavenge port for introducing a air flow into the respective cylinder bore that flows into said respective cylinder bore and diametrically across said respective cylinder bore in a direction to redirect a portion of the flow from at least one of said main scavenge ports, said supplemental scavenge ports having their centers spaced around the circumference of the respective cylinder bore more than 90.degree. from the center of the respective exhaust port, the centers of said exhaust ports all being displaced circumferentially from a perpendicular relation to said common plane in the same direction about the respective cylinder bore axis so that adjacent main scavenge passages of adjacent cylinder bores lie in side by side relation.