Under steady state, a thermal investigation has been taken to study operating temperatures and heat flow rate in the valves of a AV1 diesel engine. Temperatures, temperature fields and heat flow rate were measured under all four thermal loading conditions (full, third-fourth, half and no load) using FORCE-2 FE (finite element) software. Appropriate averaged thermal boundary conditions were set on different surfaces for FE model. Results obtained in the engine valves revealed that in addition to

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... heat transferred by convection and radiation from combustion gases, the temperature and heat flux distributions are considerably affected by heat conduction from valve seat. Contours of temperature fields introduce were shown as well. Results show that, the main cause of the valve safety is valve deformation and the great thermal stress. So it is feasible to further decrease the valve temperature with structure optimization. Measuring the temperature in different parts of the diesel engine, we can adjust the cooling, or we can improve the materials, or even we can improve the properties of the fuels. The FEA result provides effective theoretical evidence for further improving the valves' performance. The evaluation confirmed the significant variation previously observed between the various methods.