Improving Techniques to Solve the Problem of Uneven Width of Cylinder-head Valve Seat

In production of I.C.engine,valve face and guide tube hole are two of difficulties in machining.The uneven width of valve seat face is an unsolved problem in production of cylinder-head for a long time.By analysis of drawings,machining measures,this key problem is solved effectively through improving the requirement of valve seat size and machining techniques.