CYLINDER HEAD INSPECTION


  1. CLEAN VALVE

    A011AQ9

    1. Remove all carbon on the valves.

      CAUTION:

      Wear protective goggles while servicing.

  2. INSPECT CYLINDER HEAD

    A011BWFE01

    1. Using a straightedge and feeler gauge, measure the warpage of the contact surface indicated in the illustration.

      Maximum warpage
      0.05 mm (0.002 in.)

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

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

  3. INSPECT CAMSHAFT THRUST CLEARANCE


    1. Install the 2 camshafts.

    2. A011ASD

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

      Standard thrust clearance
      0.100 to 0.225 mm (0.00394 to 0.00886 in.)
      Maximum thrust clearance
      0.240 mm (0.00944 in.)

      If the thrust clearance is greater than the maximum, replace the cylinder head. If damage is found on the camshaft thrust surfaces, replace the camshaft.

  4. INSPECT CAMSHAFT OIL CLEARANCE


    1. Clean the 7 bearing caps and camshaft journals.

    2. Place the camshafts on the cylinder head.

    3. A0117FCE03
      Text in Illustration
      *1 Plastigage

      Lay a strip of Plastigage on the journal in the axial direction.

    4. A0118QU

      Place the No. 1 camshaft bearing cap and No. 2 camshaft bearing caps and tighten the bolts to the specified torque in the order shown in the illustration.

      Torque:
      No. 1 camshaft bearing cap
      15 N*m  { 153 kgf*cm, 11 ft.*lbf }
      No. 2 camshaft bearing cap
      13 N*m  { 127 kgf*cm, 9 ft.*lbf }

    5. Remove the 7 bearing caps.

    6. A0116YF

      Measure the Plastigage at its widest point.

      Standard Oil Clearance
      Item Specified Condition (Intake Side) Specified Condition (Exhaust Side)
      Camshaft No. 1 journal 0.025 to 0.061 mm (0.00098 to 0.00240 in.) 0.037 to 0.073 mm (0.00146 to 0.00287 in.)
      Camshaft other journal 0.035 to 0.072 mm (0.00138 to 0.00283 in.) 0.035 to 0.072 mm (0.00138 to 0.00283 in.)
      Maximum Oil Clearance
      Item Specified Condition (Intake Side) Specified Condition (Exhaust Side)
      Camshaft No. 1 journal 0.09 mm (0.00354 in.) 0.10 mm (0.00393 in.)
      Camshaft other journal 0.10 mm (0.00393 in.) 0.10 mm (0.00393 in.)

      If the oil clearance is greater than the maximum, replace the camshaft.

      If necessary, replace the cylinder head.

  5. INSPECT INNER COMPRESSION SPRING

    A0118KY

    1. Using a straightedge and feeler gauge, measure the deviation of the inner compression spring.

      Maximum deviation
      1.5 mm (0.059 in.)

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

  6. INSPECT INTAKE VALVE GUIDE BUSH OIL CLEARANCE


    1. A011BY5E02

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

      Intake valve guide bush inside diameter
      5.01 to 5.03 mm (0.19724 to 0.19803 in.)

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

    2. A011AEVE02

      Subtract the valve stem diameter measurement from the guide bush inside diameter measurement to calculate the oil clearance.

      Intake valve stem diameter
      4.970 to 4.985 mm (0.19567 to 0.19626 in.)
      Standard oil clearance
      0.025 to 0.060 mm (0.00098 to 0.00236 in.)
      Maximum oil clearance
      0.08 mm (0.00315 in.)

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

  7. INSPECT EXHAUST VALVE GUIDE BUSH OIL CLEARANCE


    1. A011BY5E02

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

      Exhaust valve guide bush inside diameter
      5.01 to 5.03 mm (0.19724 to 0.19803 in.)

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

    2. A011AEVE02

      Subtract the valve stem diameter measurement from the guide bush inside diameter measurement to calculate the oil clearance.

      Exhaust valve stem diameter
      4.965 to 4.980 mm (0.19547 to 0.19606 in.)
      Standard oil clearance
      0.030 to 0.065 mm (0.00118 to 0.00256 in.)
      Maximum oil clearance
      0.10 mm (0.00394 in.)

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