The Measurement of Component Friction Losses in a Fired Engine: Part 1 — Experimental Method

The direct relationship of frictional loss and fuel economy in an internal combustion engine has resulted in increasing interest in understanding the performance of the engine at the component level. Also for the development of new engine lubricants it would be better to have an in-depth analysis of the interaction of lubricants with each individual engine component under fired conditions. With the advances in data acquisition system and sensor technology, extensive study of the main engine components i.e. valve train, piston assembly and engine bearings has been possible resulting in the development of a versatile engine friction measurement system. Total engine and component friction measurement was carried out on a single cylinder Ricardo Hydra gasoline engine under fired conditions at various lubricant temperatures, engine speeds and loads. The engine was fitted with more than fifty different sensors and to sample/log data from such a large number of transducers, an advanced high-speed synchronised data acquisition system was designed/developed. Experiments are reported for total and component friction at a range of engine operating conditions with SAE 0W20 and friction-modified SAE 5W30 lubricants. Due to the nature of the research work, the findings are presented in two parts. The first part, which is this paper, explains the complex measurement methods used to measure component friction whereas the results are discussed in the second part. This system can be used as a powerful tool for screening engine oils and studying the effect of different additives on the performance of each component under realistic conditions.