Mustang GT V8-4.6L SOHC VIN X (1998)
Valve Guide: Service and Repair
If the valve stem-to-valve guide clearance exceeds the service clearance, replace the valve guide. Ream the valve guide to the standard diameter of
7.02-7.04 mm (0.276-0.277 inch). Always reface the valve seat after the valve guide has been replaced.
CAUTION: The interference angle of the valve and seat should not be lapped out. Remove all grooves or score marks from the end of the valve stem
and chamfer it as necessary. Do not remove more than 0.254 mm (0.010 inch) from the end of the valve stem.
If the valve face runout is excessive and/or to remove pits and grooves, reface the valves to a true 45-degree angle. Remove only enough stock to correct
the runout or clean up the pits and grooves. If the edge of the valve head is less than 0.794 mm (0.031 inch) thick after grinding, replace the valve
because the valve will run too hot in the engine.
If the valve or valve seat has been refaced, check the clearance between the rocker arm pad and the valve stem with the valve train installed in the engine
and replace valve stem seal.
