Abstract This paper mainly introduce the improved design on the valve system of Engine 4105. First the study on the the composition, function, principles and optimization strategy of the valve system of Engine. Second, according to automobile power and economy Asked to,slect the appropriate parameters.due to the calculate of the parameters we have slected deside the design options.Then is the optimal design,it’s mainly the optimal design of components .at the same time,draw the assembly diadram and detail diagrams of valve system using CAD(mainly Cam Shaft, valve, putt, etc.).To the improved design on system, the specific precept is design the valve system of six-cylinder diesel engine on the basis of the four-cylinder engine.the purpose of the design is synthetical application of knewledges from the textbook,improve the ability of analyzing and solving problems,and also the last exercise before go to work.
Keywords：valve; cam-line; Through capacity; Lifting
