Search Results

This paper reports work which is part of continuing research into the use of natural gas as an alternative fuel for automotive engines. Much work has previously been reported on the use of natural gas in small spark ignition engines and the optimisation of these engines. Since a large potential use of natural gas is in heavy transport engines and since few large spark ignition engines suitable for gaseous fuel are available from manufacturers, there is a need to investigate the conversion of existing diesel engines to spark ignition operation. Two naturally aspirated diesel engines were characterised in the diesel mode to determine power, fuel consumption, peak combustion pressure, exhaust gas temperature and selected emissions characteristics over the engine speed and load range. After conversion to spark ignition operation these characteristics were again determined. The effects of various engine and tune parameters on performance were evaluated.