CYLINDER HEAD INSPECTION

PROCEDURE

1. Click here

   INSPECT CYLINDER HEAD SUB-ASSEMBLY

   
   
   1. 

      *a	Cylinder Block Sub-assembly Side	*b	Intake Side
      *c	Exhaust Side	-	-

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

      Table 1. Standard Warpage

      Item	Specified Condition
      Cylinder Block Side	0 to 0.05 mm (0 to 0.00197 in.)
      Exhaust Side	0 to 0.08 mm (0 to 0.00315 in.)
      Intake Side	0 to 0.08 mm (0 to 0.00315 in.)

      Maximum warpage
      0.10 mm (0.00394 in.)

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

2. Click here

   INSPECT CYLINDER HEAD FOR CRACKS

   
   
   1. 

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

      Tip:

      If cracked, replace the cylinder head sub-assembly.

3. Click here

   INSPECT INTAKE VALVE

   
   
   1. 

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

      Standard Valve Stem Diameter
      5.470 to 5.485 mm (0.215 to 0.216 in.)

      Tip:

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

   2. 

      *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.)

      Tip:

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

   3. 

      *a	Overall Length

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

      Standard Overall Length
      105.85 mm (4.17 in.)

      Minimum Overall Length
      105.35 mm (4.15 in.)

      Tip:

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

4. Click here

   INSPECT EXHAUST VALVE

   
   
   1. 

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

      Standard Valve Stem Diameter
      5.465 to 5.480 mm (0.215 to 0.216 in.)

      Tip:

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

   2. 

      *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.)

      Tip:

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

   3. 

      *a	Overall Length

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

      Standard Overall Length
      110.40 mm (4.35 in.)

      Minimum Overall Length
      109.90 mm (4.33 in.)

      Tip:

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

5. Click here

   INSPECT INTAKE VALVE SEAT

   
   

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

   2. Lightly press the valve face against the intake valve seat.

      Note:

      Do not rotate the intake valve while pressing it.

   3. 

      *a

      Width

      Check the valve face and intake valve seat by using the following procedure:

      
      

      1. If Prussian blue appears 360° around the entire intake valve face, the valve face is concentric.

         Tip:

         If the valve face is not concentric, replace the intake valve.

      2. If Prussian blue appears 360° around the entire intake valve seat, the intake valve seat and valve face are concentric.

         Tip:

         If the valve face is not concentric, resurface the intake valve seat.

      3. Measure the width of the contact area of the intake valve seat and valve face.

         Standard Width
         1.1 to 1.5 mm (0.0433 to 0.0591 in.)

6. Click here

   INSPECT EXHAUST VALVE SEAT

   
   

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

   2. Lightly press the valve face against the exhaust valve seat.

      Note:

      Do not rotate the exhaust valve while pressing it.

   3. 

      *a

      Width

      Check the valve face and exhaust valve seat by using the following procedure:

      
      

      1. If Prussian blue appears 360° around the entire exhaust valve face, the valve face is concentric.

         Tip:

         If the valve face is not concentric, replace the exhaust valve.

      2. If Prussian blue appears 360° around the entire exhaust valve seat, the exhaust valve seat and valve face are concentric.

         Tip:

         If the valve face is not concentric, resurface the exhaust valve seat.

      3. Measure the width of the contact area of the exhaust valve seat and valve face.

         Standard Width
         1.1 to 1.5 mm (0.0433 to 0.0591 in.)

7. Click here

   INSPECT COMPRESSION SPRING

   
   
   1. 

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

      Standard Free Length
      54.53 mm (2.15 in.)

      Minimum Free Length
      52.43 mm (2.06 in.)

      Tip:

      If the free length is less than the minimum, replace the inner compression spring.

   2. 

      *a	Deviation
      *b	40 mm (1.57 in.)

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

      Maximum Deviation (Reference)
      1.4 mm (0.0551 in.)

      Tip:

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

8. Click here

   INSPECT VALVE GUIDE BUSH OIL CLEARANCE

   
   
   1. 

      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 0.12 mm (0.00472 in.) Exhaust 0.12 mm (0.00472 in.)

      Tip:

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