Experimental investigation of the effect of stratified charging system adopted to gasoline engine running with LPG on the engine performance

The preparation of air-fuel mixture, ignition and combustion is a complex process for internal combustion engine. These processes are very effective on engine performance and emission. Some studies have been conducted to improve the fuel properties for a better combustion. Additionally, some differently studies have also been focused on the principles of air and fuel transfer into the cylinder according to fuel type and engine cycle.In this study, LPG transformation was made in a gasoline engine and sequent fuel injection system was used. The air passing path and fuel injection system of the engine was modified for the stratified charge application. For this purpose, differently from the homogeneous charging systems, the around of spark plug was charged with stockhyometric mixture while the other areas of combustion chamber were charged with over poor air-fuel mixtures. Thus, the combustion was started by the ignition of rich mixtures around the spark plug and this flame lead to ignite the poor mixtures in the other parts of the combustion chamber. As a result, it is observed that the stratified charge application could run the engine with a very poor mixture. At the end of the performance experiments, the stratified charge application was showed better performance and emission, lower fuel consumption under loading and idle running conditions than homogeneous charging systems.