Internal combustion engine and method of operation

Abstract From the Canadian patent

All of combustion chambers receive a lean airfuel charge at low and medium engine power demands. As the engine power demand increases, a rich air-fuel charge is supplied to one or a suitable number of the combustion chambers with countermeasures being provided to suppress the formation of nitrogen oxides, such as an exhaust, gas recirculation (EGR) and the torch effect of a torch ignition system, the remaining combustion chambers if any, receiving a lean air-fuel charge. Exhaust gases from all of the combustion chambers are converged to oxidize hydrocarbons and carbon monoxide formed by the combustion of the rich air-fuel charge when the combustion chambers respectively receive rich and …