GS0701 A study of combustion improvement for small gasoline engine by changing the high compression ratio

The global environmental problems and the global energy problems become very serious. So it is necessary to achieve the low emission and the low fuel consumption of small gasoline engine for town use. As the first step in this study, experiments have been carried out to examine the reduction of emissions and the improvement of fuel consumption for small gasoline engine by changing the compression ratio. The main results are as follows; 1) Net thermal efficiency monotonically increases with increasing the compression ratio at same throttle valve openings. 2) CO emissions can possible to reduce by changing the high compression ratio at any throttle valve openings. 3) Emission reduction by using the high compression ratio, it is necessary to control the most suitable throttle valve openings.