Abstract: Disclosed herein is an internal combustion engine (and a method of operation thereof) comprising a piston movable relative to a combustion chamber and to a crankcase to effect cyclical pressure variation in the crankcase in response to piston movement, a transfer passage for introducing fuel-air mixture into the combustion chamber from the crankcase in response to cyclical crankcase pressure variation, an auxiliary chamber separate from the transfer passage, and a port arrangement for providing the auxiliary chamber with pressurized air in response to cyclical crankcase pressure variation and for initiating communication of the auxiliary chamber with the combustion chamber in response to piston movement during the presence of pressurized air in the auxiliary chamber and at a time other than the time of initiation of introduction of fuel-air mixture into the combustion chamber.

Abstract: A cylinder for a reciprocating piston has a depending cup-like extension leading into the firing chamber, and this extension provides a mounting for a valve accomplishing both inlet of fuel and scavenging of exhaust gases. The valve has a longitudinal bore through which the fuel is admitted to the firing chamber. The top wall of the piston has a tubular baffle extending in a direction opposite from the skirt portion of the piston to protect the cylinder from solid particles.

Abstract: A two-cycle crankcase compression internal combustion engine having extended and specially positioned intake porting and reed-type intake valves, with the porting and valves arranged to improve various of the operating characteristics of the engine.

Abstract: A two-cycle engine system of the crankcase precompression type comprising the combination of a first engine, a second engine and a combustion chamber provided with an ignition plug constructed in such a manner that the second engine is mounted in parallel and adjacent to the first engine with the combustion chamber interconnecting the first and second engines, whereby the construction becomes very compact. A rich air-fuel mixture is supplied into the combustion chamber through the second engine for ignition and a lean mixture (or air) is supplied into the first engine for scavenging and combustion so that the system provides a very compact design as well as a satisfactory performance in the reduction of the amount of harmful components in the exhaust gases.

Abstract: A multi-cylinder 2-stroke fuel injection engine of the crankcase compression type has a separate crank chamber associated with each cylinder and inlet, transfer and exhaust ports in each cylinder. The exhaust ports of the engine communicate with an exhaust manifold which communicates with the turbine of an exhaust gas driven scavenge compressor, and the impeller of the compressor communicates with an inlet manifold which communicates with the inlet ports of the engine so as to pressure charge each crank chamber and thus increase the mass of air subsequently pumped to the associated cylinder by way of its transfer port.