Abstract: A two-stroke cycle internal combustion engine (10) has a one-piece cylinder housing (14) which is vertically aligned with a crank housing (16) and a valve housing (12) mounted at a top section of the cylinder housing. The valve housing (12), cylinder housing (14), and crank housing (16) are generally formed in a substantially symmetrical manner about a vertical axis line (20). The valve housing (14) contains a valve control mechanism (54) which aids in the reversible vertical placement of a valve member (34) having an extended length value stem (38) and a valve head (36). A controlled air insertion mechanism (92) provides for high pressure air to be inserted into a combustion chamber (42) to thoroughly expel spent gases through exhaust port 46 and there is further provided a recess (102) for cooperation with a relief opening (104) to relieve gas pressures built up.

Abstract: A two stroke cycle internal combustion engine (10) is provided which has a one-piece cylinder housing (14) removably secured to a valve drive housing (12) at a top section thereof and a crank housing (16) at a bottom section. The overall combination of the valve drive housing (12), the cylinder housing (14) and the crank housing (16) are formed in a substantially symmetrical manner about a vertical axis line (18). An intake valve member (30) is positioned in a top section of cylinder housing (14) with an exhaust port (62) located at the bottom of a piston (44) travel within a combustion chamber (54). The valve member (30) opens on a downward stroke of the piston (44) which feeds compressed air into chamber (54) and forces spent gases through the exhaust port (62).