The optimized fuel injection timing during intake stroke is very important to extend the lean misfire limit of lean bum system. The effects of fuel injection timing on the combustion characteristics were investigated with a single cylinder 4 valve DOH...
The optimized fuel injection timing during intake stroke is very important to extend the lean misfire limit of lean bum system. The effects of fuel injection timing on the combustion characteristics were investigated with a single cylinder 4 valve DOHC engine with lean bum system. The fiber optic spark plug and printed circuit board head gasket ionization probe were applied to obtain the flame kernel growth rate and convection velocity in the vicinity of spark plug and flame propagation characteristics in the end zone of combustion chamber. The pressure in the combustion chamber was also measured to understand the combustion characteristics such as initial burn duration and main bum period and compared with the flame propagation.<br/>
It was found that in case of 1 valve open, the flame propagation measured by the fiber optic spark plug was consistent with the expected charge motion. The optimized fuel injection timing which has more extended lean misfire limit also showed maximum flame kernel growth rate.<br/>