INSPECT CYLINDER HEAD SUB-ASSEMBLY

INSPECT INTAKE VALVE

INSPECT EXHAUST VALVE

INSPECT INTAKE VALVE SEAT

INSPECT EXHAUST VALVE SEAT

INSPECT COMPRESSION SPRING

INSPECT VALVE GUIDE BUSH OIL CLEARANCE

INSPECT CAMSHAFT THRUST CLEARANCE

Using a precision straightedge and feeler gauge, measure the warpage of the surfaces where the cylinder head contacts the cylinder block and manifold.

• Standard Warpage:

• Item	Specified Condition
  Cylinder head lower side	0.05 mm (0.00197 in.)
  Intake side	0.08 mm (0.00315 in.)
  Exhaust side	0.05 mm (0.00197 in.)

• Maximum warpage:
• 0.10 mm (0.00394 in.)

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

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

If cracked, replace the cylinder head.

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.)

If the diameter is not as specified, replace the valve and guide bush.

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

• Standard margin thickness:
• 1.25 mm (0.0492 in.)

• Minimum margin thickness:
• 0.50 mm (0.0197 in.)

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

Using a vernier caliper, measure the valve overall length.

• Standard overall length:
• 105.85 mm (4.17 in.)

• Minimum overall length:
• 105.35 mm (4.15 in.)

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

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.)

If the diameter is not as specified, replace the valve and guide bush.

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

• Standard margin thickness:
• 1.4 mm (0.0551 in.)

• Minimum margin thickness:
• 0.50 mm (0.0197 in.)

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

Using a vernier caliper, measure the valve overall length.

• Standard overall length:
• 110.40 mm (4.35 in.)

• Minimum overall length:
• 109.90 mm (4.33 in.)

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

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

Lightly press the valve face against the valve seat.

• HINT:

• Do not rotate the valve while pressing the valve.

Check the valve face and valve seat.

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

Lightly press the valve face against the valve seat.

• HINT:

• Do not rotate the valve while pressing the valve.

Check the valve face and valve seat.

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

• Standard free length:
• 49.39 mm (1.94 in.)

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

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

• Maximum deviation:
• 1.0 mm (0.0394 in.)

• Maximum angle (reference):
• 2°

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

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

• Standard bush inside diameter:
• 5.51 to 5.53 mm (0.217 to 0.218 in.)

Subtract the valve stem diameter measurement from the 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	0.08 mm (0.00315 in.)
  Exhaust	0.10 mm (0.00394 in.)

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

Inspect the bank 1 camshafts.

Install the bank 1 camshafts.

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

• Standard thrust clearance:
• 0.08 to 0.135 mm (0.00315 to 0.00531 in.)

• Maximum thrust clearance:
• 0.15 mm (0.00591 in.)

If the thrust clearance is more than the maximum, replace the camshaft housing. If the thrust surface is damaged, replace the camshaft.

Inspect the bank 2 camshafts.