An Experimental Comparison Between Air-Assisted Injection System and High Pressure Injection System at 2-Stroke Engine

This study presents engine test results of HMC's piston-ported 2-stroke gasoline engine. This single cylinder engine of 400cc displacement has featured in direct injection(DI) of fuel and external blower scavenging of air.

Two different concepts of DI system were adopted, one is high pressure fuel injection(HPFI) system for solid fuel only and the other is low pressure air-assisted fuel injection(AAFI) system.

Two kinds of engines with different scavenging intake port shapes and areas were tested to find the effect of scavenging port type on engine performance. Also tested were trends of BSFC, BSHC and BSCO versus fuel injection timing and engine speed with HPFI and AAFI, respectively. Power and boost pressure at full load and BSFC and BSHC at part load were tested.