CYLINDER HEAD INSPECTION

PROCEDURE


  1. CLEAN CYLINDER HEAD SUB-ASSEMBLY


    1. Using a gasket scraper, remove all the gasket material from the surface of the cylinder head sub-assembly that contacts the cylinder block sub-assembly.

      Note

      Be careful not to scratch the surface of the cylinder head sub-assembly.

    2. Using a soft brush and solvent, thoroughly clean the cylinder head sub-assembly.

    3. B003MXS

      Using a valve guide bushing brush and solvent, clean all the valve guide bushes.

  2. INSPECT CYLINDER HEAD SUB-ASSEMBLY


    1. B003RT9C01
      *a Cylinder Block Sub-assembly Side
      *b Intake Manifold Side
      *c Exhaust Manifold Side

      Inspect the cylinder head sub-assembly for warpage.


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

        Maximum warpage
        0.2 mm (0.00787 in.)

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

    2. Inspect the cylinder head sub-assembly for cracks.


      1. Using a dye penetrant, check the combustion chamber, intake ports, exhaust ports and cylinder block sub-assembly surface for cracks.

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

  3. CLEAN VALVE


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

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

  4. INSPECT INTAKE VALVE


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

      Standard valve stem diameter
      7.975 to 7.990 mm (0.3140 to 0.3146 in.)

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

    2. B003KKQC06
      *a Valve Face Angle

      Check the valve face angle.


      1. Grind the valve enough to remove any pits and carbon.

      2. Check that the valve is ground to the correct valve face angle.

        Standard valve face angle
        44.5°

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

    3. B003QG1C05
      *a Margin Thickness

      Check the valve head margin thickness.

      Standard margin thickness
      1.6 mm (0.0630 in.)
      Minimum margin thickness
      1.1 mm (0.0433 in.)

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

    4. Check the overall length of the valve.

      Standard overall length
      104.1 to 104.5 mm (4.10 to 4.11 in.)
      Minimum overall length
      103.6 mm (4.08 in.)

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

    5. B003KNL

      Check the surface of the valve stem tip for wear.

      If the valve stem tip is worn, resurface the tip with a grinder or replace the intake valve.

      Note

      Do not grind the valve so it becomes shorter than the minimum overall length.

  5. INSPECT EXHAUST VALVE


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

      Standard valve stem diameter
      7.960 to 7.975 mm (0.3134 to 0.3140 in.)

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

    2. B003KKQC06
      *a Valve Face Angle

      Check the valve face angle.


      1. Grind the valve enough to remove any pits and carbon.

      2. Check that the valve is ground to the correct valve face angle.

        Standard valve face angle
        44.5°

        If the valve face is worn, replace the exhaust valve.

    3. B003QG1C05
      *a Margin Thickness

      Check the valve head margin thickness.

      Standard margin thickness
      1.7 mm (0.0669 in.)
      Minimum margin thickness
      1.2 mm (0.0472 in.)

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

    4. Check the overall length of the valve.

      Standard overall length
      103.95 to 104.35 mm (4.09 to 4.11 in.)
      Minimum overall length
      103.45 mm (4.07 in.)

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

    5. B003KNL

      Check the surface of the valve stem tip for wear.

      If the valve stem tip is worn, resurface the tip with a grinder or replace the exhaust valve.

      Note

      Do not grind the valve so it becomes shorter than the minimum overall length.

  6. INSPECT INNER COMPRESSION SPRING


    1. B003RHTC04
      *a Deviation

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

      Maximum deviation
      2.0 mm (0.0787 in.)

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

    2. B003RDS

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

      Standard free length
      46.2 mm (1.82 in.)

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

    3. B003PSW

      Using a spring tester, measure the tension of the inner compression spring at the specified installed length.

      Standard tension
      301 to 332 N (31 to 34 kgf, 66.6 to 74.6 lbf) at 37.00 mm (1.46 in.)

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

  7. INSPECT INTAKE VALVE GUIDE BUSH

    B003RVQ

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

      Standard bush inside diameter
      8.01 to 8.03 mm (0.315 to 0.316 in.)

    2. Subtract the valve stem diameter measurement (refer to the intake valve inspection procedures above) from the intake valve guide bush inside diameter measurement.

      Standard oil clearance
      0.02 to 0.055 mm (0.000787 to 0.00217 in.)
      Maximum oil clearance
      0.08 mm (0.00315 in.)

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

  8. INSPECT EXHAUST VALVE GUIDE BUSH

    B003KJS

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

      Standard bush inside diameter
      8.01 to 8.03 mm (0.315 to 0.316 in.)

    2. Subtract the valve stem diameter measurement (refer to the exhaust valve inspection procedures above) from the exhaust valve guide bush inside diameter measurement.

      Standard oil clearance
      0.035 to 0.07 mm (0.00138 to 0.00276 in.)
      Maximum oil clearance
      0.1 mm (0.00394 in.)

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

  9. INSPECT INTAKE VALVE SEAT


    1. B003KD2C02
      *a 45° Carbide Cutter

      Using a 45° carbide cutter, resurface the valve seats. Remove only enough metal to clean the valve seats.

    2. B003J3DC02
      *a Width

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

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

      Note

      Do not rotate the valve while pressing the valve against the valve seat.

    4. Check the valve face and valve seat.


      1. Check that the contact surfaces of the valve seat and valve face are in the middle area of their respective surfaces, with the width between 1.5 and 1.9 mm (0.0591 and 0.0748 in.).

        If the contact surfaces are not as specified, resurface the intake valve seat. If necessary, replace the intake valve.

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

        If the contact surfaces are not as specified, resurface the intake valve seat. If necessary, replace the intake valve.

  10. INSPECT EXHAUST VALVE SEAT


    1. B003PQPC01
      *a 45° Carbide Cutter

      Using a 45° carbide cutter, resurface the valve seats. Remove only enough metal to clean the valve seats.

    2. B003O4CC02
      *a Width

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

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

      Note

      Do not rotate the valve while pressing the valve against the valve seat.

    4. Check the valve face and valve seat.


      1. Check that the contact surfaces of the valve seat and valve face are in the middle area of their respective surfaces, with the width between 1.8 and 2.2 mm (0.0708 and 0.0866 in.)

        If the contact surfaces are not as specified, resurface the exhaust valve seat. If necessary, replace the exhaust valve.

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

        If the contact surfaces are not as specified, resurface the exhaust valve seat. If necessary, replace the exhaust valve.

  11. INSPECT VALVE LIFTER


    1. B003QRD

      Using a micrometer, measure the valve lifter diameter.

      Standard lifter diameter
      40.892 to 40.902 mm (1.6099 to 1.6103 in.)
    2. B003MA4

      Using a caliper gauge, measure the valve lifter bore diameter of the cylinder head sub-assembly.

      Standard lifter bore diameter
      40.96 to 40.98 mm (1.6126 to 1.6134 in.)

    3. Measure the oil clearance by subtracting the valve lifter diameter measurement from the valve lifter bore diameter measurement.

      Standard oil clearance
      0.058 to 0.088 mm (0.00238 to 0.00346 in.)
      Maximum oil clearance
      0.1 mm (0.00394 in.)

      If the oil clearance is more than the maximum, replace the valve lifter. If necessary, replace the cylinder head sub-assembly.

  12. INSPECT CAMSHAFT OIL CLEARANCE

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  13. INSPECT CAMSHAFT THRUST CLEARANCE

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