Abstract: A two stroke cycle engine 10 with an exhaust gas treatment catalyst. Separate reducing and oxidizing catalyst portions 126 and 127 are provided to treat different portions of the exhaust gas exhausted during each exhaust period. The portion of the exhaust gas high in NOx, usually that first exhausted upon initial opening of the exhaust port, is directed to be treated by the reducing catalyst 126 and the remainder of the exhaust gas is directed to be treated by the oxidizing catalyst 127.

Abstract: A fuel injection system for a multi-cylinder internal combustion engine, which includes a rigid elongated unitary member incorporating a gas supply duct, a fuel supply duct and a fuel return duct, each of which extends in the direction of elongation of the unitary member. A separate fuel metering device and fuel injecting device is provided for each engine cylinder. The fuel metering device is arranged to deliver metered quantities of fuel to the fuel injection device and is in communication with the fuel supply and fuel return ducts so that fuel can be circulated through each of the fuel metering devices. The fuel injecting devices are each in communication with the gas duct and communicable with one of the engine cylinders. The fuel injection devices are adapted to effect delivery of a metered quantity of fuel entrained in gas supplied from the gas duct when the fuel injecting device is in fluid communication with a cylinder.

Abstract: A two-stroke spark ignited engine (10) with direct fuel injection (14) and an exhaust gas treatment catalyst. A separate catalyst unit (23) is provided for each combustion chamber (11) and is located at or adjacent each exhaust port (15) from that chamber and that during a cycle of each combustion chamber (11) the catalyst unit (23) of that combustion chamber (11) is exposed only to exhaust gases which change from chemically reducing to chemically oxidizing during the cycle. An engine which has exhaust gases which are overall chemically oxidizing can thus nevertheless have the NOx constituents of the gases reduced.

Abstract: A two stroke cycle engine 10 with an exhaust gas treatment catalyst. Separate reducing and oxidizing catalyst portions 126 and 127 are provided to treat different portions of the exhaust gas exhausted during each exhaust period. The portion of the exhaust gas high in NOx, usually that first exhausted upon initial opening of the exhaust port, is directed to be treated by the reducing catalysts 126 and the remainder of the exhaust gas is directed to be treated by the oxidizing catalyst 127.

Abstract: A fuel injection system for a multi-cylinder internal combustion engine, which includes a rigid elongated unitary member incorporating a gas supply duct, a fuel supply duct and a fuel return duct, each of which extends in the direction of elongation of the unitary member. A separate fuel metering device and fuel injecting device is provided for each engine cylinder. The fuel metering device is arranged to deliver metered quantities of fuel to the fuel injection device and is in communication with the fuel supply and fuel return ducts so that fuel can be circulated through each of the fuel metering devices. The fuel injecting devices are each in communication with the gas duct and communicable with one of the engine cylinders. The fuel injection devices are adapted to effect delivery of a metered quantity of fuel entrained in gas supplied from the gas duct when the fuel injecting device is in fluid communication with a cylinder.