CYLINDER HEAD INSPECTION

PROCEDURE

  1. INSPECT CYLINDER HEAD SUB-ASSEMBLY

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

      A293312C01

      *a

      Cylinder Block Side

      *b

      Exhaust Manifold Side

      *c

      Intake Manifold Side

      -

      -

      Maximum Warpage

      Item

      Specified Condition

      Cylinder block side

      0.05 mm (0.00197 in.)

      Exhaust manifold side

      0.05 mm (0.00197 in.)

      Intake manifold side

      0.05 mm (0.00197 in.)

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

    2. A111294

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

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

  2. INSPECT INNER COMPRESSION SPRING

    1. A101392

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

      Standard Free Length

      45.9 mm (1.81 in.)

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

    2. A101393C03

      *a

      Deviation

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

      Maximum Deviation

      1.5 mm (0.0591 in.)

      Maximum Angle (Reference)

      2°

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

  3. INSPECT INTAKE VALVE

    1. A126904

      Using a gasket scraper, chip off any carbon from the intake valve head.

      Note:

      Be careful not to damage the intake valve face.

    2. Using a wire brush, thoroughly clean the intake valve.

    3. A101394C01

      *a

      Overall Length

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

      Standard Overall Length

      104.4 mm (4.11 in.)

      Minimum Overall Length

      104.1 mm (4.10 in.)

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

    4. A101395

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

      Standard Valve Stem Diameter

      5.970 to 5.985 mm (0.23504 to 0.23563 in.)

      If the diameter is not as specified, replace the intake valve.

    5. A101396C01

      *a

      Margin Thickness

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

      Standard Margin Thickness

      1.40 to 1.60 mm (0.0551 to 0.0630 in.)

      Minimum Margin Thickness

      0.50 mm (0.0197 in.)

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

  4. INSPECT EXHAUST VALVE

    1. A126904

      Using a gasket scraper, chip off any carbon from the exhaust valve head.

      Note:

      Be careful not to damage the exhaust valve face.

    2. Using a wire brush, thoroughly clean the exhaust valve.

    3. A101397C01

      *a

      Overall Length

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

      Standard Overall Length

      104.1 mm (4.10 in.)

      Minimum Overall Length

      103.8 mm (4.09 in.)

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

    4. A101398

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

      Standard Valve Stem Diameter

      5.960 to 5.975 mm (0.23464 to 0.23524 in.)

      If the diameter is not as specified, replace the exhaust valve

    5. A293305C01

      *a

      Margin Thickness

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

      Standard Margin Thickness

      1.36 to 1.56 mm (0.0535 to 0.0614 in.)

      Minimum Margin Thickness

      0.50 mm (0.0197 in.)

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

  5. INSPECT VALVE GUIDE BUSH

    1. A111370

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

      Standard Bush Inside Diameter

      6.010 to 6.030 mm (0.23661 to 0.23740 in.)

      If the bush inside diameter is not as specified, check the oil clearance.

    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

      0.035 to 0.070 mm (0.00138 to 0.00276 in.)

      Maximum Oil Clearance

      Item

      Specified Condition

      Intake

      0.06 mm (0.00236 in.)

      Exhaust

      0.07 mm (0.00276 in.)

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

  6. 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.

      Tip:

      Do not rotate the valve while pressing it.

    3. Check the intake valve face and intake valve seat by using the following procedure.

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

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

      3. A101377C01

        *a

        Width

        Check that the intake valve seat contacts in the middle of the intake valve face with a contact surface width between 1.0 and 1.4 mm (0.0394 and 0.0551 in.).

  7. 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.

      Tip:

      Do not rotate the valve while pressing it.

    3. Check the exhaust valve face and exhaust valve seat by using the following procedure.

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

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

      3. A293304C01

        *a

        Width

        Check that the exhaust valve seat contacts in the middle of the exhaust valve face with a contact surface width between 1.0 and 1.4 mm (0.0394 and 0.0551 in.).

  8. INSPECT CAMSHAFT OIL CLEARANCE

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