CYLINDER HEAD INSPECTION


  1. INSPECT CYLINDER HEAD SUB-ASSEMBLY

    A01HOJCE09
    Text in Illustration
    *a Cylinder Head Lower Side
    *b Intake Side
    *c Exhaust Side

    1. Using a precision straightedge and feeler gauge, measure the warpage of the contact surface of the cylinder block sub-assembly and manifolds.

      Standard Warpage
      Item Warpage
      Cylinder head lower 0.05 mm (0.00197 in.)
      Intake 0.08 mm (0.00315 in.)
      Exhaust 0.08 mm (0.00315 in.)
      Maximum Warpage
      Item Warpage
      Cylinder head lower 0.10 mm (0.00394 in.)
      Intake 0.10 mm (0.00394 in.)
      Exhaust 0.10 mm (0.00394 in.)

      If the warpage is greater than the maximum, replace the cylinder head sub-assembly.

  2. INSPECT CYLINDER HEAD FOR CRACKS


    1. A01HP0R

      Using a dye penetrant, check the intake ports, exhaust ports and cylinder surface for cracks.

      If cracked, replace the cylinder head sub-assembly.

  3. INSPECT INTAKE VALVE


    1. A01HN5T

      Using a micrometer, measure the diameter of the valve stem.

      Valve stem diameter
      5.470 to 5.485 mm (0.2154 to 0.2159 in.)

      If the valve stem is not as specified, check the oil clearance.

    2. A01HNG3E04
      Text in Illustration
      *a Margin thickness

      Using a vernier caliper, measure the valve head margin thickness.

      Standard margin thickness
      1.0 mm (0.0394 in.)
      Minimum margin thickness
      0.5 mm (0.0197 in.)

      If the margin thickness is less than the minimum, replace the intake valve.

    3. A01HNF4E03
      Text in Illustration
      *a Overall Length

      Using a vernier caliper, measure the valve overall length.

      Standard overall length
      105.85 mm (4.1673 in.)
      Minimum overall length
      105.35 mm (4.1476 in.)

      If the overall length is less than the minimum, replace the intake valve.

  4. INSPECT EXHAUST VALVE


    1. A01HME2

      Using a micrometer, measure the diameter of the valve stem.

      Valve stem diameter
      5.465 to 5.480 mm (0.2152 to 0.2157 in.)

      If the valve stem is not as specified, check the oil clearance.

    2. A01HP5RE04
      Text in Illustration
      *a Margin thickness

      Using a vernier caliper, measure the valve head margin thickness.

      Standard margin thickness
      1.0 mm (0.0394 in.)
      Minimum margin thickness
      0.5 mm (0.0197 in.)

      If the margin thickness is less than the minimum, replace the exhaust valve.

    3. A01HPCHE03
      Text in Illustration
      *a Overall Length

      Using a vernier caliper, measure the valve overall length.

      Standard overall length
      110.40 mm (4.3464 in.)
      Minimum overall length
      109.90 mm (4.3268 in.)

      If the overall length is less than the minimum, replace the exhaust valve.

  5. INSPECT INTAKE VALVE SEAT


    1. Apply a light coat of Prussian blue to the valve face.

    2. Lightly press the valve face against the valve seat.

    3. A01HN93E06
      Text in Illustration
      *a Width

      Check the valve face and valve seat by using the following procedure:


      1. If Prussian blue appears around the entire valve face, the valve face is concentric. If not, replace the valve.

      2. If Prussian blue appears around the entire valve seat, the valve seat and valve face are concentric. If not, resurface the valve seat.

      3. Check that the valve seat contacts the middle of the valve face with the width between 1.1 and 1.5 mm (0.0433 and 0.0591 in.).

  6. INSPECT EXHAUST VALVE SEAT


    1. Apply a light coat of Prussian blue to the valve face.

    2. Lightly press the valve face against the valve seat.

    3. A01HN93E06
      Text in Illustration
      *a Width

      Check the valve face and valve seat by using the following procedure:


      1. If Prussian blue appears around the entire valve face, the valve face is concentric. If not, replace the valve.

      2. If Prussian blue appears around the entire valve seat, the valve seat and valve face are concentric. If not, resurface the valve seat.

      3. Check that the valve seat contacts the middle of the valve face with the width between 1.1 and 1.5 mm (0.0433 and 0.0591 in.).

  7. INSPECT INNER COMPRESSION SPRING


    1. A01HQJK

      Using a vernier caliper, measure the free length of the inner compression spring.

      Free length
      45.91 mm (1.8075 in.)

      If the free length is not as specified, replace the inner compression spring.

    2. A01HOOKE04
      Text in Illustration
      *a Deviation

      Using a steel square, measure the deviation of the inner compression spring.

      Maximum deviation
      1.0 mm (0.0394 in.)
      Maximum angle (reference)
      2°

      If the deviation is greater than the maximum, replace the inner compression spring.

  8. INSPECT VALVE GUIDE BUSH OIL CLEARANCE


    1. A01HR46

      Using a caliper gauge, measure the inside diameter of the valve guide bush.

      Bush inside diameter
      5.510 to 5.530 mm (0.2169 to 0.2177 in.)

    2. Subtract the valve stem diameter measurement from the valve guide bush inside diameter measurement.

      Standard Oil Clearance
      Item Clearance
      Intake 0.025 to 0.060 mm (0.000984 to 0.00236 in.)
      Exhaust 0.030 to 0.065 mm (0.00118 to 0.00256 in.)
      Maximum Oil Clearance
      Item Clearance
      Intake 0.08 mm (0.00315 in.)
      Exhaust 0.10 mm (0.00394 in.)

      If the clearance is greater than the maximum, replace the valve and valve guide bush.