About one third of the heat produced inside the cylinder during the combustion process goes as waste by transferring it to the coolant. If the amount of heat transferred to the coolant was reduced by a considerable amount, the heat would be used to perform the useful work, thus increasing the thermal efficiency of the engine. In this work a thin layer of coating was given to the piston, cylinder head, and liner. A series of numerical investigations were conducted in uncoated cylinder, insulating top surface of the piston alone, insulating cylinder head and liner and finally by insulating all the three and data were collected at different crank position. Three types of insulating materials were used for coating and analysis was done at different crank positions. The results prove that the heat transfer from the engine may be reduced to a considerable amount after coating thereby the thermal efficiency of a diesel engine would be increased.

Keywords: Insulation, piston, cylinder head, liner, crank angle