From the environmental conscious point of view, subjects of conventional two-stroke engines will be irregular combustion and new mixture shortcut. Concerning for the irregular combustion, our previous papers has however proven that timing controlled auto-ignition, namely Activated Radical (AR) Combustion, was an effective solution. Meanwhile for the new mixture shortcut, no solution is mentioned in those papers.
This time, a low pressure pneumatic direct fuel injection engine has been experimented. This engine is however intended to perform homogeneous combustion, the A R Combustion solves irregular combustion effectively in the light load range. Fuel is pneumatically injected into the cylinder by using accumulated in-cylinder gas pressure, after the scavenging process performed by the air only. A mechanically driven rotary type injector is installed in the cylinder wall. Wide spray generated by this injector facilitates homogeneous combustion even in high speed high load range, which promises a higher maximum power out put. Simplicity in the mechanism and control requires a minimum additional friction and electricity to solve the irregular combustion and new mixture shortcut.
The bench test results show a remarkable reduction in fuel consumption and exhaust emissions as successfully maintaining high power out put of original two-stroke engines.