An Investigation of the Cylinder Wall Oil Film Development During Warm-Up of An SI Engine Using Laser-Induced Fluorescence

The single-point LIF-measurement technique has been applied to a four-cylinder spark-ignition production engine for investigation of the oil film layer between the piston, piston rings and the cylinder wall. The lubrication process was studied during engine warm-up and it was found that a scaling law could be successfully used. This scaling law enables simple scaling of the oil film thickness of the compression ring, scraper ring and on the liner during warm-up, assuming the oil film thickness and cylinder liner temperature are known for the steady-state operating condition. Thereby the value of traditional measured steady-state lubrication data is enhanced.