Abstract: A two cycle radial engine assembly ?10! includes a crankcase assembly ?12! supporting an annular cylinder closure means ?23! having a part-spherical sealing surface ?26! against which the correspondingly formed outer ends of cylinders ?19!, disposed in a rotary cylinder assembly ?20!, operatively seal. A crankshaft assembly ?11! supported by said crankcase assembly operates pistons ?14! within the cylinders ?19! which are spaced evenly about the crankshaft axis with the axes of the cylinders contained in a common radial plane ?29!. The cylinder assembly ?20! is gear connected to the crankshaft ?11! for rotation in the reverse direction to the crankshaft ?11! and inlet and outlet ports ?40/41! extending through the cylinder closure means ?23! communicate sequentially with the rotating cylinders ?19! to enable inlet and exhaust gases to be induced into or expelled from the cylinders.

Abstract: A radial engine assembly (10) includes a crankcase (12) supporting an annular cylinder closure means (23) having a part-spherical sealing surface (26). A crankshaft (11) supported by the crankcase (12) operates piston (32) within radial cylinders of a coplanar cylinder assembly (20). The crankshaft (11) and the cylinder assembly (20) are geared for reverse rotation. A main connecting rod (16) is journalled to the crankshaft (11) and the other connecting rods (17) are journalled to the main connecting rod (16). Circumferentially extending inlet ports (60, 61) communicate respectively with primary and secondary barrels of a fuel/air supply device.