CYLINDER HEAD INSPECTION

PROCEDURE


  1. INSPECT CYLINDER HEAD FOR FLATNESS


    1. Using a precision straightedge and feeler gauge, check the surfaces which contact the cylinder block sub-assembly and manifolds for warpage.

      B000U5WC02
      *a Cylinder Head Bottom *b Intake Side
      *c Exhaust Side - -
      Standard Warpage
      Item Specified Condition
      Cylinder Head Bottom 0.05 mm (0.00197 in.)
      Intake Side 0.08 mm (0.00315 in.)
      Exhaust Side 0.05 mm (0.00197 in.)
      Maximum Warpage
      0.10 mm (0.00394 in.)

      If the warpage is more than the maximum, replace the cylinder head.

  2. INSPECT CYLINDER HEAD FOR CRACKS


    1. B000V85

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

      Tech Tips

      If cracks are found, replace the cylinder head.

  3. INSPECT INTAKE VALVE


    1. B000WBU

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

      Standard Valve Stem Diameter
      5.470 to 5.485 mm (0.215 to 0.216 in.)

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

      Click here

    2. B000TPUC08
      *a Margin Thickness

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

      Standard Margin Thickness
      1.25 mm (0.0492 in.)
      Minimum Margin Thickness
      0.50 mm (0.0197 in.)

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

    3. B000Z6RC23
      *a Overall Length

      Using a vernier caliper, measure the valve overall length.

      Standard Overall Length
      105.85 mm (4.17 in.)
      Minimum Overall Length
      105.35 mm (4.15 in.)

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

  4. INSPECT EXHAUST VALVE


    1. B000XW7

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

      Standard Valve Stem Diameter
      5.465 to 5.480 mm (0.215 to 0.216 in.)

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

      Click here

    2. B000U99C24
      *a Margin Thickness

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

      Standard Margin Thickness
      1.4 mm (0.0551 in.)
      Minimum Margin Thickness
      0.50 mm (0.0197 in.)

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

    3. B000Z6RC23
      *a Overall Length

      Using a vernier caliper, measure the valve overall length.

      Standard Overall Length
      110.40 mm (4.35 in.)
      Minimum Overall Length
      109.90 mm (4.33 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 intake valve face.

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

      Note

      Do not rotate the intake valve.

    3. B000YOMC01
      *a Width

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


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

        If not, resurface the intake valve seat.

      2. Check that the contact surfaces of the intake valve seat and intake valve face are even around the entire valve seat.

        If not, resurface the intake valve seat.

  6. INSPECT EXHAUST VALVE SEAT


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

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

      Note

      Do not rotate the exhaust valve.

    3. B000V67C01
      *a Width

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


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

        If not, resurface the exhaust valve seat.

      2. Check that the contact surface of the exhaust valve seat and exhaust valve face are even around the entire valve seat.

        If not, resurface the exhaust valve seat.

  7. INSPECT INTAKE VALVE COMPRESSION SPRING


    1. B000Z15

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

      Standard Free Length
      52.17 mm (2.05 in.)

      Tech Tips

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

    2. B000YIQC02
      *a Deviation

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

      Maximum Deviation
      1.7 mm (0.0669 in.)
      Maximum Angle (Reference)
      2°

      Tech Tips

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

  8. INSPECT EXHAUST VALVE COMPRESSION SPRING


    1. B000Z15

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

      Standard Free Length
      52.16 mm (2.05 in.)

      Tech Tips

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

    2. B000YIQC02
      *a Deviation

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

      Maximum Deviation
      1.7 mm (0.0669 in.)
      Maximum Angle (Reference)
      2°

      Tech Tips

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

  9. INSPECT VALVE GUIDE BUSH OIL CLEARANCE


    1. B000WLR

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

      Standard Guide Bush Inside Diameter
      5.510 to 5.530 mm (0.217 to 0.218 in.)

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

      Standard Oil Clearance
      Item Specified Condition
      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 Specified Condition
      Intake 0.08 mm (0.00315 in.)
      Exhaust 0.10 mm (0.00394 in.)

      Tech Tips

      If the oil clearance is greater than the maximum, replace the intake or exhaust valve and valve guide bush.

  10. INSPECT CAMSHAFT THRUST CLEARANCE


    1. for Bank 1:


      1. Install the No. 3 camshaft sub-assembly.

        Click here

      2. Install the No. 4 camshaft sub-assembly.

        Click here

      3. B000Z9U

        Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.

        Standard Thrust Clearance
        0.110 to 0.165 mm (0.00433 to 0.00650 in.)
        Maximum Thrust Clearance
        0.175 mm (0.00689 in.)

        If the camshaft thrust clearance is greater than the maximum, replace the cylinder head.

        If the camshaft thrust surface is damaged, replace the No. 3 camshaft sub-assembly or No. 4 camshaft sub-assembly.

    2. for Bank 2:


      1. B000V0U

        Install the camshaft.

        Click here

      2. Install the No. 2 camshaft.

        Click here

      3. Using a dial indicator, measure the thrust clearance while moving the camshaft and No. 2 camshaft back and forth.

        Standard Thrust Clearance
        0.110 to 0.165 mm (0.00433 to 0.00650 in.)
        Maximum Thrust Clearance
        0.175 mm (0.00689 in.)

        If the camshaft thrust clearance is greater than the maximum, replace the cylinder head.

        If the camshaft thrust surface is damaged, replace the camshaft or No. 2 camshaft.