CYLINDER HEAD INSPECTION

PROCEDURE


  1. INSPECT CYLINDER HEAD FOR FLATNESS


    1. Using a precision straightedge and feeler gauge, measure the warpage of the contact surfaces where the cylinder head sub-assembly contacts the cylinder block sub-assembly, intake manifold and exhaust manifold converter sub-assembly.

      A0047UZC02
      *a Cylinder Head Sub-assembly Bottom Side *b Intake Manifold Side
      *c Exhaust Manifold Converter Sub-assembly Side - -
      Maximum Warpage
      Item Specified Condition
      Cylinder head sub-assembly bottom side 0.05 mm (0.00197 in.)
      Intake manifold side 0.10 mm (0.00394 in.)
      Exhaust Manifold Converter Sub-assembly Side 0.10 mm (0.00394 in.)

      Tech Tips

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

  2. INSPECT CYLINDER HEAD FOR CRACKS


    1. A0047PR

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

      Tech Tips

      If cracks are found, replace the cylinder head sub-assembly.

  3. INSPECT VALVE SEAT


    1. A0047DAC09
      *a Width

      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 according to the following procedure:

      Note

      Do not rotate the valve while pressing it.


      1. If Prussian blue appears 360° around the valve face, the valve face is concentric. If not, replace the valve.

      2. If Prussian blue appears 360° around the valve seat, the guide and valve face are concentric. If not, resurface the valve seat.

      3. Check that the valve seat contact is in the middle of the valve face with the valve seat width between 1.0 and 1.4 mm (0.0394 and 0.0551 in).

  4. INSPECT CAMSHAFT THRUST CLEARANCE


    1. Clean the camshaft, No. 2 camshaft and camshaft bearing caps.

    2. Place the camshaft and No. 2 camshaft on the camshaft housing sub-assembly.

    3. Install the camshaft bearing caps.

      Click here

    4. Install the camshaft housing sub-assembly.

      Click here

    5. A0048Y8

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

      Standard Thrust Clearance
      Item Specified Condition
      Intake side 0.06 to 0.20 mm (0.00236 to 0.00787 in.)
      Exhaust side 0.06 to 0.20 mm (0.00236 to 0.00787 in.)
      Maximum Thrust Clearance
      Item Specified Condition
      Intake side 0.215 mm (0.00846 in.)
      Exhaust side 0.215 mm (0.00846 in.)

      Tech Tips

      If the thrust clearance is more than the maximum, replace the camshaft housing sub-assembly. If the thrust surface is damaged, replace the camshaft.

  5. INSPECT CAMSHAFT OIL CLEARANCE


    1. Clean the camshaft, No. 2 camshaft and camshaft bearing caps.

    2. Place the camshaft and No. 2 camshaft on the camshaft housing sub-assembly.

    3. A004B1PC03
      *a Plastigage

      Lay a strip of Plastigage across each of the camshaft journals.

      Note

      Do not turn the camshaft and No. 2 camshaft.

    4. Install the camshaft bearing caps.

      Click here

    5. Install the camshaft housing sub-assembly.

      Click here

    6. Remove the camshaft bearing caps.

      Click here

    7. A004946C03
      *a Plastigage

      Measure the Plastigage at its widest point.

      Standard Oil Clearance
      Item Specified Condition
      No. 1 journal 0.030 to 0.067 mm (0.00118 to 0.00264 in.)
      Other journals 0.030 to 0.067 mm (0.00118 to 0.00264 in.)
      Maximum Oil Clearance
      Item Specified Condition
      No. 1 Camshaft journal 0.08 mm (0.00315 in.)
      Other camshaft journals 0.08 mm (0.00315 in.)

      Note

      Completely remove the Plastigage.

      Tech Tips

      If the oil clearance is more than the maximum, replace the camshaft. If necessary, replace the camshaft housing sub-assembly.

  6. INSPECT OUTER COMPRESSION SPRING


    1. A004A9F

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

      Standard Free Length
      57.13 mm (2.25 in.)
    2. A0046S8C28
      *a Steel Square

      Using a steel square and feeler gauge, measure the deviation of the outer compression spring.

      Maximum Deviation
      1.75 mm (0.0689 in.)
      Maximum Angle
      2°

      Tech Tips

      If the deviation is more than the maximum, replace the outer compression spring.

  7. INSPECT INTAKE VALVE


    1. A0047EBC12
      *a Overall Length

      Using a vernier caliper, measure the overall length of the intake valve.

      Standard Overall Length
      103.35 mm (4.07 in.)
      Minimum Overall Length
      102.85 mm (4.05 in.)

      Tech Tips

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

    2. A004A5L

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

      Standard Valve Stem Diameter
      5.470 to 5.485 mm (0.21535 to 0.21594 in.)

      Tech Tips

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

    3. A0048CSC04
      *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.)

      Tech Tips

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

  8. INSPECT EXHAUST VALVE


    1. A004B8FC27
      *a Overall Length

      Using a vernier caliper, measure the overall length of the exhaust valve.

      Standard Overall Length
      104.5 mm (4.11 in.)
      Minimum Overall Length
      104.0mm (4.09 in.)

      Tech Tips

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

    2. A00474V

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

      Standard Valve Stem Diameter
      5.465 to 5.480 mm (0.21516 to 0.21575 in.)

      Tech Tips

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

    3. A004B76C04
      *a Margin Thickness

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

      Standard Margin Thickness
      1.15 mm (0.0453 in.)
      Minimum Margin Thickness
      0.65 mm (0.0256 in.)

      Tech Tips

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

  9. INSPECT VALVE GUIDE BUSH OIL CLEARANCE


    1. A004954

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

      Standard Valve 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 0.080 mm (0.00315 in.)
      Exhaust 0.085 mm (0.00335 in.)

      Tech Tips

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