Two-cycle internal combustion engine

Claim 1

In a combustion chamber for a two-cycle internal combustion engine having a cylinder, a cylinder head and a reciprocating piston defining a variable volume combustion chamber comprised at minimum volume conditions of a first portion of relatively small volume formed in said cylinder head formed from a pair of generally flat side walls and a substantially rectangular planar top wall forming an open channel groove shape having an inlet end and an opposed outlet end surrounded on all sides but its outlet end by a squish area and a second portion of larger volume communicating at one side thereof with the outlet end of said first portion, a spark plug carried by said cylinder head with its gap in said first portion, scavenge port means in said cylinder for admitting a charge to said combustion chamber and configured to direct said charge toward the inlet end of said first portion, said second portion having its largest cross-sectional area adjacent said outlet end of said first portion, said largest cross-sectional area having an area greater than said outlet end and the cross-sectional area of said second portion continuously decreasing toward a side opposite the one side that communicates with said first portion.