Novel measurement techniques for oil consumption and spark plug temperature measurement to support engine components development in terms of wear and in situ monitoring

Large engines will continue to play a major role in the transportation sector, especially in shipping. In the energy sector, they are essential due to increasingly complex networks and operating strategies. These two sectors are set up for a renewable world through their use of large engines operated with alternative, preferably carbon-free fuels. Intensive research will remain necessary to make these engines even more climate-friendly, to further increase their lifetime and to reduce production, operating and maintenance costs. This research will be supported by the development and deployment of novel key technologies. This paper describes two of these technologies that have been developed at the Large Engines Competence Center: a temperature measurement spark plug and a system for measuring engine oil consumption. Both technologies have in common that they should help engines to run more efficiently, cleaner and with less wear. Spark plug wear impacts engine reliability and maintenance costs. Likewise, wear of the piston assembly and its tribological system is of great importance. This paper provides insight into the development of both technologies and the first instance of their simultaneous application on an engine test bench. It also reveals how spark plug temperature, oil consumption and emissions parameters correlate with each other. The results of an extensive running-in program and endurance runs are presented, and the influence of the manufacturing tolerance of the piston rings on wear and lubricating oil consumption is shown. •A novel method for lube oil consumption measurement has been implemented and tested on a large single-cylinder engine fueled by natural gas.•Different power units have been compared in terms of their lubricating oil consumption, tribological behavior, and wear.•A novel technique for spark plug temperature measurement has been successfully installed and tested.•A spark plug middle electrode measurement is presented with unlimited measurement time at high accuracy and minor modifications.•Strong correlations between spark plug temperature, lube oil consumption and soot and NOx emissions have been observed.