CYLINDER HEAD

INSPECT CYLINDER HEAD FOR FLATNESS

*a	Cylinder Head Bottom	*b	Intake Side
*c	Exhaust Side	-	-

Using a precision straightedge and feeler gauge, check the surfaces which contact the cylinder block sub-assembly and manifolds for warpage.

Standard Warpage

Item	Specified Condition
Cylinder Head Bottom	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.

Click here

INSPECT CYLINDER HEAD FOR CRACKS

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

Tip:
If cracks are found, replace the cylinder head.

Click here

INSPECT INTAKE VALVE

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 valve stem is not as specified, check the valve guide bush oil clearance.
Click here
*a Margin Thickness

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.
*a Overall Length

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.

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

Standard Margin Thickness
1.25 mm (0.0492 in.)

Minimum Margin Thickness
0.50 mm (0.0197 in.)

Standard Overall Length
105.85 mm (4.17 in.)

Minimum Overall Length
105.35 mm (4.15 in.)

Click here

INSPECT EXHAUST 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 valve stem is not as specified, check the valve guide bush oil clearance.
Click here
*a Margin Thickness

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.
*a Overall Length

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.

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

Standard Margin Thickness
1.4 mm (0.0551 in.)

Minimum Margin Thickness
0.50 mm (0.0197 in.)

Standard Overall Length
110.40 mm (4.35 in.)

Minimum Overall Length
109.90 mm (4.33 in.)

Click here

INSPECT INTAKE VALVE SEAT

Apply a light coat of Prussian blue to the intake valve face.
Lightly press the intake valve face against the intake valve seat.

Note:
Do not rotate the intake valve.
*a Width

Check the intake valve face and intake valve seat by using the following procedure:
1. Check that the intake valve seat contacts the middle of the intake valve face with the width between 1.1 and 1.5 mm (0.0433 and 0.0591 in.).
  
  If not, resurface the intake valve seat.
2. Check that the contact surfaces of the intake valve seat and intake valve face are even around the entire valve seat.
  
  If not, resurface the intake valve seat.

Click here

INSPECT EXHAUST VALVE SEAT

Apply a light coat of Prussian blue to the exhaust valve face.
Lightly press the exhaust valve face against the exhaust valve seat.

Note:
Do not rotate the exhaust valve.
*a Width

Check the exhaust valve face and exhaust valve seat by using the following procedure:
1. Check that the exhaust valve seat contacts the middle of the exhaust valve face with the width between 1.3 and 1.7 mm (0.0512 and 0.0669 in.).
  
  If not, resurface the exhaust valve seat.
2. Check that the contact surface of the exhaust valve seat and exhaust valve face are even around the entire valve seat.
  
  If not, resurface the exhaust valve seat.

Click here

INSPECT INNER COMPRESSION SPRING

*A	Type A
*B	except Type A
*1	Valve Spring Retainer
*2	Inner Compression Spring
*a	Diameter
	Paint Mark

Tip:

Type A and except Type A can be distinguished by the paint mark of the inner compression spring.

Type	Valve Spring Retainer Diameter	Inner Compression Spring Paint Mark
A	14 mm (0.551 in.)	Intake Side: Pink Exhaust: Light Green
except A	16.8 mm (0.661 in.)	Intake Side: Orange Exhaust: Light Blue

Type

Valve Spring Retainer Diameter

Inner Compression Spring Paint Mark

A

14 mm (0.551 in.)

Intake Side: Pink

Exhaust: Light Green

except A

16.8 mm (0.661 in.)

Intake Side: Orange

Exhaust: Light Blue

Type A:

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

Standard Free Length
Intake
49.41 mm (1.95 in.)
Exhaust
49.48 mm (1.95 in.)

Tip:

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

*a Deviation

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

Maximum Deviation

1.7 mm (0.0669 in.)

Maximum Angle (Reference)

2°

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

Maximum Deviation
1.7 mm (0.0669 in.)

Maximum Angle (Reference)
2°

except Type A:

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

Standard Free Length
Intake
52.17 mm (2.05 in.)
Exhaust
52.16 mm (2.05 in.)

Tip:

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

*a Deviation

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

Maximum Deviation

1.8 mm (0.0709 in.)

Maximum Angle (Reference)

2°

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

Maximum Deviation
1.8 mm (0.0709 in.)

Maximum Angle (Reference)
2°

Click here

INSPECT VALVE GUIDE BUSH OIL CLEARANCE

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

Standard Guide Bush Inside Diameter

5.510 to 5.530 mm (0.217 to 0.218 in.)

Standard Guide Bush Inside Diameter
5.510 to 5.530 mm (0.217 to 0.218 in.)

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	0.08 mm (0.00315 in.)
Exhaust	0.10 mm (0.00394 in.)

Tip:

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

Click here

INSPECT CAMSHAFT THRUST CLEARANCE

for Bank 1:
1. Install the No. 3 camshaft sub-assembly.
  
  Click here
2. Install the No. 4 camshaft sub-assembly.
  
  Click here
3. Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.
  
  Standard Thrust Clearance
  
  0.08 to 0.14 mm (0.00315 to 0.00551 in.)
  
  Maximum Thrust Clearance
  
  0.15 mm (0.00591 in.)
  
  If the camshaft thrust clearance is greater than the maximum, replace the cylinder head.
  If the camshaft thrust surface is damaged, replace the No. 3 camshaft sub-assembly or No. 4 camshaft sub-assembly.
for Bank 2:
1. Install the camshaft.
  Click here
2. Install the No. 2 camshaft.
  
  Click here
3. Using a dial indicator, measure the thrust clearance while moving the camshaft and No. 2 camshaft back and forth.
  
  Standard Thrust Clearance
  
  0.08 to 0.14 mm (0.00315 to 0.00551 in.)
  
  Maximum Thrust Clearance
  
  0.15 mm (0.00591 in.)
  
  If the camshaft thrust clearance is greater than the maximum, replace the cylinder head.
  
  If the camshaft thrust surface is damaged, replace the camshaft or No. 2 camshaft.

CYLINDER HEAD INSPECTION