Valve and Seat Reconditioning Procedure
WARNING: This page is about a different variant/trim than selected.
- If the valve seat width, roundness or concentricity is beyond specifications, you must grind the seats in order to ensure proper heat dissipation and prevent the buildup of carbon on the seats.
- A NEW valve must be used with any reconditioned seat.
- Grind the valve seats (2) to the proper angle specification listed in Engine Mechanical Specifications .
- Using the proper angle specification listed in Engine Mechanical Specifications , grind, relieve, the valve seats (1) to correctly position the valve seating surface (2) to the valve.
- Using the proper angle specification listed in Engine Mechanical Specifications , grind, undercut, the valve seats (3) to narrow the valve seat widths to the specifications listed in Engine Mechanical Specifications .
- When grinding the seats, grind off as little material as possible. Cutting valve seat results in lowering the valve spring pressure.
- Install the valve in the cylinder head. Do not lap the valves under any condition, whether the valves are new or used.
- After obtaining the proper valve seat width in the cylinder head, you must re-measure the valve stem height using the Valve Stem Height Measurement Procedure.
- If the valve stem height is acceptable, test the seats for concentricity using the Valve-to-Seat Concentricity Measurement Procedure.
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