CYLINDER HEAD INSPECTION


  1. CLEAN CYLINDER HEAD SUB-ASSEMBLY

    A01BBX6E01

    1. Clean the cylinder head.


      1. Using a gasket scraper, remove all gasket material from the cylinder block contact surface.

        Note

        Be careful not to scratch the cylinder block contact surface.

    2. A01BESAE01

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

    3. A01BH6CE01

      Using a soft brush and solvent, thoroughly clean the cylinder head.

  2. INSPECT CYLINDER HEAD SUB-ASSEMBLY

    A01BE35E02

    1. Inspect the cylinder head warpage.


      1. Using a precision straightedge and feeler gauge, measure the surfaces, which contact the cylinder block and the manifolds, for warpage.

        Maximum warpage
        0.15 mm (0.005 in.)

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

    2. A01BA7WE01

      Inspect the cylinder head for cracks.


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

        If cracked, replace the cylinder head.

  3. CLEAN INTAKE VALVE

    A01BBN5E01

    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

    A01BCXZE01

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

      Standard valve stem diameter
      5.970 to 5.985 mm (0.2350 to 0.2356 in.)

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

    2. A01BD97E04

      Check the valve face angle.


      1. Grind the valve enough to remove 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 is worn, replace the valve.

    3. A01BEEZE03

      Check the valve head margin thickness.

      Standard margin thickness
      1.1 mm (0.043 in.)
      Minimum margin thickness
      0.8 mm (0.032 in.)

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

    4. A01BHZHE03

      Check the valve overall length.

      Standard overall length
      105.15 to 105.75 mm (4.1398 to 4.1634 in.)
      Minimum overall length
      104.65 mm (4.1201 in.)

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

    5. A01BHULE01

      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 valve.

      Note

      Do not grind off more than the minimum.

  5. CLEAN EXHAUST VALVE

    A01BBN5E01

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

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

  6. INSPECT EXHAUST VALVE

    A01BCXZE01

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

      Standard valve stem diameter
      5.960 to 5.975 mm (0.2346 to 0.2352 in.)

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

    2. A01BD97E04

      Check the valve face angle.


      1. Grind the valve enough to remove 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 valve.

    3. A01BEEZE03

      Check the valve head margin thickness.

      Standard margin thickness
      1.2 mm (0.047 in.)
      Minimum margin thickness
      0.7 mm (0.028 in.)

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

    4. A01BHZHE03

      Check the valve overall length.

      Standard overall length
      105.02 to 105.62 mm (4.1347 to 4.1583 in.)
      Minimum overall length
      104.52 mm (4.1150 in.)

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

    5. A01BHULE01

      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 valve.

      Note

      Do not grind off more than the minimum.

  7. INSPECT INNER COMPRESSION SPRING

    A01BFUDE03

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

      Maximum deviation
      2.0 mm (0.079 in.)

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

    2. A01BAXHE01

      Using vernier calipers, measure the free length of the spring.

      Standard free length
      46.5 mm (1.831 in.)

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

    3. A01BDCDE01

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

      Standard installed tension (at 33.1 mm (1.303 in.))
      150.2 to 165.8 N (15.3 to 16.9 kgf, 33.7 to 37.3 lbf)

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

  8. INSPECT INTAKE VALVE GUIDE BUSH

    A01BB58E02

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

      Standard bush inside diameter
      6.01 to 6.03 mm (0.2366 to 0.2374 in.)

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

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

      Standard oil clearance
      0.025 to 0.060 mm (0.0010 to 0.0024 in.)
      Maximum oil clearance
      0.08 mm (0.0032 in.)

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

  9. INSPECT EXHAUST VALVE GUIDE BUSH

    A01BHEYE02

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

      Standard bush inside diameter
      6.01 to 6.03 mm (0.2366 to 0.2374 in.)

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

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

      Standard oil clearance
      0.035 to 0.070 mm (0.0014 to 0.0028 in.)
      Maximum oil clearance
      0.10 mm (0.0039 in.)

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

  10. INSPECT INTAKE VALVE SEAT

    A01BBGLE05

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

    2. A01BH82E01

      Check the valve seating position.


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

      2. Lightly press the valve against the seat. Do not rotate the valve.

    3. Check the valve face and seat for the following:


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

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

      3. Check that the seat contact is in the middle of the valve face with the width below.

        Standard width
        1.2 to 1.6 mm (0.047 to 0.063 in.)

  11. INSPECT EXHAUST VALVE SEAT

    A01BAWDE02

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

    2. A01BA7CE01

      Check the valve seating position.


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

      2. Lightly press the valve against the seat. Do not rotate valve.

    3. Check the valve face and seat for the following:


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

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

      3. Check that the seat contact is in the middle of the valve face with the width below.

        Standard width
        1.6 to 2.0 mm (0.063 to 0.079 in.)

  12. INSPECT VALVE LIFTER

    A01BERNE01

    1. Using a micrometer, measure the lifter diameter.

      Standard lifter diameter
      30.966 to 30.976 mm (1.2191 to 1.2195 in.)
    2. A01BFTAE01

      Using a caliper gauge, measure the lifter bore diameter of the cylinder head.

      Standard lifter bore diameter
      31.000 to 31.021 mm (1.2205 to 1.2213 in.)

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

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

      Standard oil clearance
      0.024 to 0.055 mm (0.0009 to 0.0022 in.)
      Maximum oil clearance
      0.095 mm (0.0037 in.)

      If the oil clearance is greater than the maximum, replace the lifter. If necessary, replace the cylinder head.

  13. INSPECT CYLINDER HEAD SET BOLT

    A01BG4VE01

    1. Using a vernier caliper, measure the minimum outside diameter of the compressed thread at the measuring point A.

      Standard outside diameter
      11.76 to 11.97 mm (0.463 to 0.471 in.)
      Minimum outside diameter
      11.6 mm (0.457 in.)

      If the outside diameter is less than the minimum, replace the bolt.

  14. INSPECT CAMSHAFT

    A01BEPNE01

    1. Inspect the circle runout.


      1. Place the camshaft on V-blocks.

      2. Using a dial indicator, measure the circle runout.

        Maximum circle runout
        0.03 mm (0.0012 in.)

        If the circle runout is greater than the maximum, replace the camshaft.

    2. A01BAWUE01

      Inspect the cam lobe height.


      1. Using a micrometer, measure the cam lobe height.

        Standard cam lobe height
        47.180 to 47.280 mm (1.8575 to 1.8614 in.)
        Minimum cam lobe height
        46.760 mm (1.8409 in.)

        If the cam lobe height is less than the minimum, replace the camshaft.

    3. A01BHQOE01

      Inspect the journal diameter of the camshaft.


      1. Using a micrometer, measure the journal diameter of the camshaft bearing.

        Standard journal diameter
        27.969 to 27.985 mm (1.1011 to 1.1018 in.)

        If the journal diameters is not as specified, check the oil clearance.

    4. A01BGRQE01

      Check the oil clearance.


      1. Clean the bearing caps and journals.

      2. Check the bearings for flaking and scoring.

        If the bearings are damaged, replace the bearing caps and cylinder head as a set.

      3. Install the bearings onto the bearing caps and cylinder head.

      4. Place the camshaft on the cylinder head.

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

      6. A01BEOWE01

        Install the bearing caps.

        Note

        Do not turn the camshaft.

      7. Remove the bearing caps.

      8. A01BEUME01

        Measure the Plastigage at its widest point.

        Standard oil clearance
        0.025 to 0.062 mm (0.0010 to 0.0024 in.)
        Maximum oil clearance
        0.10 mm (0.0039 in.)

        If the oil clearance is greater than the maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.

      9. Completely remove the Plastigage.

      10. Remove the camshaft. Click here

    5. A01BDQUE01

      Check the thrust clearance.


      1. Install the camshaft. Click here

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

        Standard thrust clearance
        0.035 to 0.185 mm (0.0014 to 0.0073 in.)
        Maximum thrust clearance
        0.25 mm (0.0098 in.)

        If the thrust clearance is greater than the maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.

    6. A01BE98E01

      Using a dial indicator, measure the backlash.


      1. Install the 2 camshafts.

      2. Using a dial indicator, measure the backlash.

        Standard backlash
        0.035 to 0.089 mm (0.0014 to 0.0035 in.)
        Maximum backlash
        0.189 mm (0.0074 in.)

        If the backlash is greater than the maximum, replace the camshaft.

      3. Remove the 2 camshafts. Click here

  15. INSPECT NO.2 CAMSHAFT

    A01BHWXE01

    1. Inspect the circle runout.


      1. Place the camshaft on V-blocks.

      2. Using a dial indicator, measure the circle runout.

        Maximum circle runout
        0.03 mm (0.0012 in.)

        If the circle runout is greater than the maximum, replace the camshaft.

    2. A01BAWUE01

      Inspect the cam lobe height.


      1. Using a micrometer, measure the cam lobe height.

        Standard cam lobe height
        48.071 to 48.171 mm (1.8925 to 1.8965 in.)
        Maximum cam lobe height
        47.920 mm (1.8866 in.)

        If the cam lobe height is less than the minimum, replace the camshaft.

    3. A01BHQOE01

      Inspect the journal diameter of the camshaft.


      1. Using a micrometer, measure the journal diameter of the camshaft bearing.

        Standard journal diameter
        27.969 to 27.985 mm (1.1011 to 1.1018 in.)

        If the journal diameters is not as specified, check the oil clearance.

    4. A01BC73E02

      Check the oil clearance.


      1. Clean the bearing caps and journals.

      2. Check the bearings for flaking and scoring.

        If the bearings are damaged, replace the bearing caps and cylinder head as a set.

      3. Install the bearings onto the bearing caps and cylinder head.

      4. Place the camshaft on the cylinder head.

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

      6. A01BI6BE01

        Install the bearing caps.

        Note

        Do not turn the camshaft.

      7. Remove the bearing caps.

      8. A01BETDE02

        Measure the Plastigage at its widest point.

        Standard oil clearance
        0.025 to 0.062 mm (0.0010 to 0.0024 in.)
        Maximum oil clearance
        0.10 mm (0.0039 in.)

        If the oil clearance is greater than the maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.

      9. Completely remove the Plastigage.

      10. Remove the camshaft. Click here

    5. A01BBO1E01

      Check the thrust clearance.


      1. Install the camshaft. Click here

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

        Standard thrust clearance
        0.035 to 0.185 mm (0.0014 to 0.0073 in.)
        Maximum thrust clearance
        0.25 mm (0.0098 in.)

        If the thrust clearance is greater than the maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.

      3. Remove the camshaft. Click here