VALVE MECHANISM ASSEMBLY METHOD OF ENGINE AND DEVICE THEREOF

PROBLEM TO BE SOLVED: To ensure a proper valve clearance easily by positioning a cam shaft bound by a cam cap for a cylinder head to upper limit or lower limit and measuring a clearance between a pace circle section of a cam and a tappet to select the optimum shim. SOLUTION: In a valve mechanism assembly process, when a cylinder head 1 on which a valve 4 and a cam cap 11 are assembled is carried in, the cam cap 11 is first removed by a disassembly device, then a tappet 7 is inserted and a standard shim 13 is assembled by manual operation, and then a cam shaft 5 and the cam cap 11 are assembled. Next, after the posture of the cylinder head 1 is held in such a manner that an axial line of the valve 4 faces the vertical direction, the cam shaft 5 is hoisted by a positioning means to position it at an upper limit position. A clearance X between a cam base circle section 9a and the standard shim 13 at this time is measured, a shim having the optimum thickness is selected based on the results of the measurement, and the optimum shim is assembled.