The D3106 engine is a natural intake, direct injection, in-line four-stroke, three-cylinder diesel engine. The structure of valve train can be divided into two parts: Valve Train and valve train. The main function of the valve group is to seal the intake and exhaust ports; the main function of the valve group is to transmit the action force from the crankshaft timing gear to the valve, which causes the valve to open or close at regular intervals.