Effects of Lubricant Temperature in a Motorized Engine

This paper explains the effect of various lubricant and engine temperatures on the intake mass air flow, engine noise and lubricant pressure behaviour of a motor-driven spark ignition engine. The lubricant pressure, engine noise and mass air flow changes were recorded under a steady state operating condition with an increased engine speed in which both the volume and temperature of the lubricant remained unchanged for each sets of test. The engine was driven by an electric motor at a wide-open throttle and a constant speed ranging from 500 to 3000 rpm with 500 rpm increment. The lubricant and cooling water were set at 32°C (unheated) and 90°C (heated) for each run. In general, the pressure of the lubricant was found to decrease for either increased engine speed or lubricant temperature. It was found that high lubricant viscosity produced high overall engine friction and resulted to a higher engine noise. Heated lubricant started off with a very low pressure with 0.996 bar compared to unheated lubricant with 2.497 bar in 500 rpm. Unheated engine lubricant recorded a peak noise of 107.2 dB at 1500 rpm before it dropped momentarily before increased linearly beyond this speed. The findings in this work are useful for researchers in the field of automotive technologies, environmental and triblogies.