Evaluation of a Spark Plug by the Preignition Simulator

To evaluate the quality of a spark plug against the preignition, a new preignition simulator has been developed. The principle of this apparatus is to estimate the occurrence of preignition caused by a temperature rise in the electrode.

The engine is operated with repeated stepwise shifting of spark timing by 55° CA advance from the MET condition. The number of advanced cycles is increased until the occurrence of real preignitions. By the number of advanced cycles when preignition occurs, the quality of the spark plug with respect to preignition can be evaluated.

From this test result, it is confirmed that this preignition simulator is very useful for the practical application of experimental testing.