A simple method was devised for predicting how much the crank pin journal temperature of a modified bearing specification would change in relation to the baseline specification. In this study, analyses were first conducted to determine the oil flow rate at the big-end bearing which is a major determinant of the crank pin journal temperature. A bearing oil flow rate analysis was conducted by using the bearing oil film thickness found by an elastohydrodynamic lubrication(EHL)analysis and the crank pin oil hole outlet pressure found by an oil hole pressure analysis, and the bearing oil flow rate was predicted. An analysis was then conducted to predict the crank pin journal temperature using the oil flow rate and friction loss found by the oil flow rate analysis and EHL analysis. That method was then used to examine the effect of each bearing specification on the amount of change in the crank pin journal temperature.
