The Effect of Spring Design as Return Cycle of Two Stroke Spark Ignition Linear Engine on the Combustion Process and Performance

Problem statements: The effects of optimization on spring design of the linear engine with spring mechanism in its performance and combustion process have been examined. However, at certain conditions the engine can not work properly as predicted. This can happen because displacement of engine stroke is depending on thrust forces of combustion process in cylinder of the engine. For that, some speed range can not open the scavenging ports, some speed can not open properly and most speeds range work normal. Moreover, pressure ratio also decrease depend on deflection of spring characteristics. Approach: This research examined the performance of engine at certain conditions in which displacement of spring did not work normal, such at 1, 4.1 and 4.6 m sec^-1 speed. It was necessary to examine because at that speeds intake scavenging port did not open properly. Therefore, simulation technique had been adopted to solve of the problems. Results: The combustion pressure and power output were compared with prediction result. Conclusion: The results were significant drop of Indicated Mean Effective Pressure (IMEP) and impacted reduced in power output. At three parts only 1 m sec^-1 speed of linear engine could work normal.