Abstract
Relations of each factor affected by emissions and the prediction of performance have been analyzed numerically by cycle simulation in the Spark Ignition Engine. Through theoretical analysis and experiments, the results are obtained as below. The calculated results and the experimental ones are almost highly agreeable on cycle simulation model, exhaust gas analysis and efficiency for processes in cylinder. Therefore this model is proved appropriate and can be useful for optimum design of Spark Ignition Engines on parametric studies. It is reaffirmed that the Wiebe's function is suitable for predicting Combustion Ration in Spark Ignition Engines. On parametric studies, it is found that optimum conditions whose density of emissions are lower and efficiency is maximum within propriety value are crankangle ATDC $15^\circ-20^\circ$, 2400 rpm. A/F=16 in this experiment.