Select Fitting

In the case of valve stem-to-valve guide clearance, the service clearance is intended as an aid to diagnosing engine noise only, and does not constitute a failure or indicate need for service. However, when overhauling or reconditioning a cylinder head, the service clearance should be regarded as having a practical working value, and used to determine installation of the next oversize valve.

If the valve stem-to-valve guide clearance exceeds the service clearance, ream the valve guide for the next oversize valve stem. Valves with oversize stem diameters of 0.38 mm and 0.76 mm (0.015 inch and 0.030 inch) are available in diameters of 0.41 mm and 0.81 mm (0.016 inch and 0.032 inch) oversize. Always reface the valve seat after the valve guide has been reamed.