Valve Guide: Service and Repair

Valve guides are an integral part of the cylinder head and are not replaceable. When valve stem to guide clearance exceeds specification, ream the valve guide bores to accommodate the next larger oversize valve stem. Oversize valves are available with .003, .015 and .030 inch stem diameter sizes. Ream valve guides in steps, starting with the .003 inch oversize reamer and progressing to size required.