The Measurement of Component Friction Losses in a Fired Engine: Part 2 — Experimental Results

Bench testing can provide rapid and cost effective information for developing new lubricants. But there is general agreement that the only satisfactory means of evaluating the behaviour of engine oil is by actual use in engine. Also for detailed analysis of the tribological interaction it is important to analyse the engine performance at the component level. With the help of advance data acquisition system and sensor technology, experimental measurement of friction losses at the component level have been measured at realistic engine operating conditions, using the technique explained in Part 1. This paper describes the outcome of the experimental results at a range of engine operating conditions using mainly SAE 0W20 lubricant and some results from a friction-modified SAE 5W30 lubricant. The results clearly show considerable changes in the percentage contribution of power loss between low and high lubricant temperatures. The change in mode of lubricating regime from boundary to fluid film lubrication can be seen at the component level with increase in engine speed and decrease in lubricant temperature. This system can be used as a powerful tool for screening engine oils, analysing component design, validating friction models and studying the effect of different additives on the performance of each component under realistic operating conditions.