Piston Temperatures of an Automobile Engine

Abstract

The piston temperatures of a Nissan-Automobile E-type 1200 cc gasoline engine were measured by the thermocouples, of which the lead-wires were passed through the combustion chamber and led to the stationary position. The influences of the pistion speed, load, cooling water, ignition advance, knocking and mixture ratio upon the piston temperature were examined. The following was worth noticing. (1) When the engine speed was 4 500 rpm under full load, the maximum temperature was about 200°C at the center of the piston head. (2) When the ignition timing was advanced, the piston temperature proportionally rose. Especially when knocking occurred, its maximum temperature reached 260°C, which was 60°C higher than that in case of the normal operation. (3) With weak mixture ratio, the temperature of exhaust gas rose, but there was little influence upon the piston temperature.