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Home › Honda › 2007 › Element SC, Automatic › Repair and Diagnosis › Engine Mechanical › Mechanical › Cylinder Head › Valve Seat Reconditioning

Valve Seat Reconditioning

  1. Inspect valve stem-to-guide clearance (see VALVE INSPECTION  ). If the valve guides are worn, replace them (see VALVE GUIDE REPLACEMENT  ) before cutting the valve seats.
  2. Renew the valve seats in the cylinder head using a valve seat cutter.
    Fig 1: Reaming Valve Seats In Cylinder Head
    G05448657Courtesy of AMERICAN HONDA MOTOR CO., INC.
  3. Carefully cut a 45° seat, removing only enough material to ensure a smooth and concentric seat.
  4. Bevel the upper and lower edges at the angles shown in the illustration. Check the width of the seat and adjust accordingly.
    Fig 2: Identifying Upper & Lower Edges At Angles
    G05448658Courtesy of AMERICAN HONDA MOTOR CO., INC.
  5. Make one more very light pass with the 45° cutter to remove any possible burrs caused by the other cutters.

    Valve Seat Width 

    Standard (New): 1.25-1.55 mm (0.049-0.061 in.) 

    Service Limit: 2.00 mm (0.079 in.) 

  6. After resurfacing the seat, inspect for even valve seating. Apply Prussian Blue compound (A) to the valve face. Insert the valve in its original location in the head, then lift it and snap it closed against the seat several times.
    Fig 3: Identifying Prussian Blue Compound Applying Area
    G05448659Courtesy of AMERICAN HONDA MOTOR CO., INC.
  7. The actual valve seating surface (B), as shown below by the blue compound, should be centered on the seat.
    • If it is too high (closer to the valve stem), you must make a second cut with the 67.5° cutter to move it down, then one more cut with the 45° cutter to restore seat width.
    • If it is too low (close to the valve edge), you must make a second cut with the 35° cutter (intake side) or the 30° cutter (exhaust side) to move it up, then make one more cut with the 45° cutter to restore seat width.
    NOTE: The final cut should always be made with the 45° cutter.
  8. Insert the intake and exhaust valves in the head, and measure valve stem installed height (A).

    Intake Valve Stem Installed Height 

    Standard (New): 44.0-44.5 mm (1.73-1.75 in.) 

    Service Limit: 44.7 mm (1.76 in.) 

    Exhaust Valve Stem Installed Height 

    Standard (New): 44.1-44.6 mm (1.74-1.76 in.) 

    Service Limit: 44.8 mm (1.76 in.) 

    Fig 4: Identifying Valve Stem Height
    G05448660Courtesy of AMERICAN HONDA MOTOR CO., INC.
  9. If valve stem installed height is beyond the service limit, replace the valve and recheck. If it is still beyond the service limit, replace the cylinder head, the valve seat in the head is too deep.
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