Studies of Test Methods for Evaluating Two-Cycle Engine Oils

In Japan, test methods for evaluating the performance of 2-cycle engine oils have been developed separately by each 2-cycle engine manufacturer. The reason for this is that there are are many differences in engine performance and in lubrication methods.

Evaluation through bench tests is used as a valid method for screening engine oils prior to field tests. Field tests are conducted eventually as the most reliable test method for evaluating the performance of engine oils.

Yamaha Motor, one of the leading Japanese 2-cycle engine manufacturers, developed a “70 min engine test method” in 1963, which can be conducted in a relatively short period of time with good reproducibility. In this paper, several problems regarding Yamaha's 70 min engine test method are discussed.