Valve and Valve Seat

Valve-Stem Diameter





1. Measure the diameter of each intake and exhaust valve stem at the points shown. Verify the diameter is within specification.

^ If out of specification, install new components as necessary.

Valve-Stem to Valve Guide Clearance





Special Tool(s)

NOTE: Valve stem diameter must be within specifications before checking valve stem to valve guide clearance.





1. NOTE: If necessary, use a magnetic base.

Install a Valve Stem Clearance Tool on the valve stem and install a Dial Indicator with Bracketry. Lower the valve until the Valve Stem Clearance Tool contacts the upper surface of the valve guide.

2. Move the Valve Stem Clearance Tool toward the indicator and zero the indicator. Move the Valve Stem Clearance Tool away from the indicator and note the reading. The reading will be DOUBLE the valve stem-to-valve guide clearance. Valves with oversize stems will need to be installed if out of specification.

Valve-Inspection





1. Inspect these valve areas:
1. the end of the stem for grooves or scoring
2. the valve face and the edge for pits, grooves or scores
3. the valve head for signs of burning, erosion, warpage and cracking
4. the valve margin for wear

Valve-Seat Inspection

Valve and Seat Refacing Measurements

CAUTION: After grinding valves or valve seats, check valve clearance.





1. Check the valve head and seat.
^ Check valve angles.
^ Check margin width.

^ Be sure margin width is within specification
2. Inspect for abnormalities on the valve face and seat.

Valve-Seat Width





1. Measure the valve seat width. If necessary, grind the valve seat to specification.
^ Measure the intake valve seat width.
^ Measure the exhaust valve seat width.
^ Recheck the valve spring installed length after the seats have been ground, and shim the valve springs as necessary to achieve the correct installed spring length.

Valve-Seat Runout





1. Use the Valve Seat Runout Gauge to check valve seat runout.