Mustang Cobra V8-281 4.6L DOHC VIN V MFI (1997)
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Replace as necessary.
VALVE STEM CLEARANCE
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Measure the valve guide inner diameter.
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Subtract the valve stem diameter from the valve guide diameter. This is the valve stem to guide clearance.
Intake, 0.020-0.069 mm (0.000787-0.002717 inch).
Exhaust, 0.046-0.095 mm (0.001810-0.003740 inch).
Maximum, 0.200 mm (0.00800 inch).
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If the clearance is greater than specified, replace the valve or valve guide, or both, depending on the dimension that is causing the excess
clearance.
VALVE STEM END REFINISHING
CAUTION: Do not remove more than 0.254 mm (0.010 inch) from the end of the valve stem.
Remove all grooves or score marks from the end of the valve stem and chamfer it as necessary.
VALVE HEAD MARGIN THICKNESS
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Inspect the valve head margin thickness of each valve. If measurement is out of specification replace valve as the valve will run too hot in the
engine.
Exhaust and Intake: 0.79 mm (1/32 inch).
VALVE FACE RUNOUT
If the valve face runout is excessive and/or it is necessary to remove pits and grooves, reface the valve to a true 45.5° angle. Remove only enough
stock to correct the runout or to clean up the pits and grooves. Maximum runout: 0.05 mm (0.002 inch).
VALVE SEAT
The center of the valve face should contact the valve seat in approximately the center. Check Cylinder Head Valve Seat and repair if necessary.
