Sensitivity and Effect of Variable Ignition Timing and Engine Speed on the Performance of a Spark Ignition Engine

The combustion process in a spark ignition engine is a progressive reaction, and thus certain factors such as the timing of ignition, combustion duration, the end of combustion etc. have considerable effect on performance of an engine. The work enhanced the importance of design variables of I.C. engine for better performance with fewer emissions. The spark timing and compression ratio are the two important design variables to deal with for effective performance of engine. This paper presents the effects of spark timing and RPM on the performance of a four stroke single-cylinder spark ignition engine. The study evaluated results of research in the area of spark ignition engine and is assessed by studying its performance characteristics relative to find the optimum. Experiments were conducted at different combustion start at 10, 14, 18, 22, 26, 30, 34, 38 degrees BTDC and for engine speed of 500, 1500, 3400 and 5000rpm. The performance of a spark ignition engine is investigated under different values of ignition advance. By varying the ignition timing i.e. related to top dead centre, the results of some characteristics such as power, torque, thermal efficiency, pressure, and brake specific flue consumption are obtained and compared.