Development of a high efficiency low emissions E85 (bio ethanol) green lawn mower engine

Single cylinder small displacement nonroad engines commonly used for lawn and garden care, power generation, etc., have a very significant impact on emissions production. The EPA has passed regulations that call for a 35% reduction of hydrocarbon emissions over the years 2011-12. This research focused on fuel injecting a single cylinder spark ignition (SI) 15.7kW (21HP) 33cin (540cc) engine and further developing it to operate on E85 ethanol bio-fuel in order to meet and exceed the upcoming EPA requirements. Preliminary testing resulted in an 80% reduction of carbon monoxide (CO) and 60% reduction of hydrocarbon (HC) emissions compared to the carbureted fuel setup. These emissions reductions were obtained at operating speeds of 1250-2750rpm and load conditions of 1-5bar bmep. The adaptation of the engine for fuel injection and E85 operation required a newly designed intake manifold and instrumentation, but the engine remained unmodified.