Temperature Measurements of the Connecting Rod, Piston Pin and Crankpin Bearing of an Automobile Gasoline Engine

The thermocouple wires were led from the connecting rod to the piston through in a coil which received a twisting stress only in the piston pin. From here the wires were led out by means of the"combustion chamber pass through and on the circular spring"method that had been used by the authors. From the measuring results, the followings were found. (i) The heat flow from the piston reaches to the middle part of the connecting rod, at the big end, however, this effect fade away. The temperatures of the crankpin and main bearing metal rise a certain extent above the surroundings by the friction. (ii) These temperatures are increased proportionately with the engine speed. (iii) An increasing the oil temperature increases the temperatures of the bearing-metals as same extent as it.