THE INFLUENCE OF VALVE TIMING ON IN-CYLINDER PRESSURE SPARK IGNITION ENGINES PERFORMANCE CHARACTERISTICS

Abstract

The performance of the engine depends on many factors. One of the factors is valve timing known to be the timing of opening and closing of valves that has a significant effect on the in-cylinder performance. However, there is less information in the study about valve timing effect on single cylinder engine performances. In this study, the focus is to analyze in-cylinder pressure characteristics on a single piston fuel injection for a spark-ignition engine. This can be done by simulating the effects of valve timing on in-cylinder pressure. The methodology of this project will be simulation-based by using commercial one-dimensional software. The research results are engine performance parameters which are volumetric efficiency, brake torque, brake power, and cylinder pressure in 1000 to 5500 RPM engines. The results show a positive increment in engine performance from the baseline model (CTA240) which is 9.06% for brake power, 2.85% for brake torque, and 13.09% for volumetric efficiency. At low engine speed, it was also found improvement in cylinder pressure when advancing the intake valve timing opening (IVO) by 20 to 25 degrees bTDC. For high speed, the cylinder pressure was found to improve once the retardation of intake valve timing closing (IVC) was done between 40 to 45 degrees aBDC by comparing it with the baseline results. The result highlights the importance of intake valve timing setup by varying the opening and closing of the intake valve to give better output for engine performance.