CYLINDER HEAD INSPECTION

  1. INSPECT CYLINDER HEAD SUB-ASSEMBLY

    A011VC3E09
    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. Using a dye penetrant, check the intake ports, exhaust ports and cylinder surface for cracks.

      A011RP5

      If cracked, replace the cylinder head sub-assembly.

  3. INSPECT INTAKE VALVE

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

      A011R7V
      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. Using a vernier caliper, measure the valve head margin thickness.

      A011U4WE04
      Text in Illustration
      *a 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. Using a vernier caliper, measure the valve overall length.

      A011SKUE03
      Text in Illustration
      *a 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. Using a micrometer, measure the diameter of the valve stem.

      A011V0E
      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. Using a vernier caliper, measure the valve head margin thickness.

      A011U4IE04
      Text in Illustration
      *a 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. Using a vernier caliper, measure the valve overall length.

      A011QWKE03
      Text in Illustration
      *a 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. Check the valve face and valve seat by using the following procedure:

      A011S0RE06
      Text in Illustration
      *a Width

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

      A011S0RE06
      Text in Illustration
      *a Width

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

      A011QLJ
      Free length
      45.91 mm (1.8075 in.)

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

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

      A011R6EE04
      Text in Illustration
      *a Deviation
      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. Using a caliper gauge, measure the inside diameter of the valve guide bush.

      A011TSY
      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.