Removal and Replacement

CYLINDER HEAD

COMPONENTS:

INSPECTION

1. INSPECT CYLINDER HEAD SUB-ASSEMBLY
(a) Using a precision straightedge and feeler gauge, measure the warpage of the contact surfaces of the cylinder block and manifold.

Standard warpage:

Maximum warpage: 0.10 mm (0.0039 in.)
If the warpage is greater than the maximum, replace the cylinder head.

(b) Using a dye penetrant, check the intake ports, exhaust ports and cylinder surface for cracks.
If cracked, replace the cylinder head.

2. INSPECT INTAKE VALVE
(a) Using a micrometer, measure the diameter of the valve stem.
Standard valve stem diameter: 5.470 to 5.485 mm (0.2154 to 0.2159 in.)

(b) 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.

(c) Using a vernier caliper, measure the valve's overall length.
Standard overall length: 105.85 mm (4.1673 in.)
Minimum overall length: 105.35 mm (4.1476 in.)
If the overall length is less than the minimum, replace the intake valve.

3. INSPECT EXHAUST VALVE
(a) Using a micrometer, measure the diameter of the valve stem.
Standard valve stem diameter: 5.465 to 5.480 mm (0.2152 to 0.2157 in.)

(b) 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.

(c) Using a vernier caliper, measure the valve's overall length.
Standard overall length: 110.40 mm (4.3465 in.)
Minimum overall length: 109.90 mm (4.3268 in.)
If the overall length is less than the minimum, replace the exhaust valve.

4. INSPECT INTAKE VALVE SEAT
(a) Apply a light coat of Prussian blue to the valve face.
(b) Lightly press the valve face against the valve seat.

HINT: Do not rotate the valve while pressing the valve.

(c) Check the valve face and valve seat.
(1) Check that the contact surfaces of the valve seat and valve face are in the middle area of their respective surfaces, with the width between 1.1 to 1.5 mm (0.0433 to 0.0591 in.).
If not, correct the valve seat.
(2) Check that the contact surfaces of the valve seat and valve face are even around the entire valve seat.
If not, correct the valve seat.

5. INSPECT EXHAUST VALVE SEAT
(a) Apply a light coat of Prussian blue to the valve face.
(b) Lightly press the valve face against the valve seat.
(c) Check the valve face and valve seat.
(1) Check that the contact surfaces of the valve seat and valve face are in the middle area of their respective surfaces, with the width between 1.1 to 1.5 mm (0.0433 to 0.0591 in.).
If not, correct the valve seat.
(2) Check that the contact surface of the valve seat and valve face are even around the entire valve seat.
If not, correct the valve seat.

6. INSPECT INNER COMPRESSION SPRING
(a) Using a vernier caliper, measure the free length of the inner compression spring.
Standard free length: 51.70 mm (2.0354 in.)
If the free length is not as specified, replace the spring.

(b) 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 greater than the maximum, replace the spring.

7. INSPECT VALVE GUIDE BUSH OIL CLEARANCE
(a) Using a caliper gauge, measure the inside diameter of the guide bush.
Standard bush inside diameter: 5.51 to 5.53 mm (0.2169 to 0.2177 in.)
(b) Subtract the valve stem diameter measurement from the guide bush inside diameter measurement.

Standard oil clearance:

Maximum oil clearance:

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

8. INSPECT CAMSHAFT THRUST CLEARANCE
(a) Inspect the bank 1 camshafts.
(1) Install the bank 1 camshafts.

(2) Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.
Standard thrust clearance: 0.08 to 0.13 mm (0.0031 to 0.0051 in.)
Maximum thrust clearance: 0.15 mm (0.006 in.)
If the thrust clearance is greater than the maximum, replace the cylinder head. If the thrust surface is damaged, replace the camshaft.
(b) Inspect the bank 2 camshafts.
(1) Install the bank 2 camshafts.
(2) Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.
Standard thrust clearance: 0.08 to 0.13 mm (0.0031 to 0.0051 in.)
Maximum thrust clearance: 0.15 mm (0.006 in.)
If the thrust clearance is greater than the maximum, replace the cylinder head. If the thrust surface is damaged, replace the camshaft.

REPLACEMENT
1. REPLACE INTAKE VALVE GUIDE BUSH
(a) Heat the cylinder head to approximately 80 to 100°C (176 to 212°F).
(b) Place the cylinder head on wooden blocks.

(d) Using a caliper gauge, measure the bush bore diameter of the cylinder head side.
Standard cylinder bore diameter: 10.285 to 10.306 mm (0.4049 to 0.4057 in.)
If the bush bore diameter of the cylinder head is between 10.285 to 10.306 mm (0.4049 to 0.4057 in.), proceed to the next step.
If the bush bore diameter of the cylinder head is 10.356 mm (0.4077 in.) or more, replace the cylinder head.
(e) Select a new guide bush (STD or O/S 0.05), and measure its diameter.
(f) Machine the bush bore diameter of the cylinder head side to the diameter of the selected guide bush.

Bush bore diameter:

(g) Heat the cylinder head to approximately 80 to 100°C (176 to 212°F).

(h) Using SST and a hammer, tap in a new guide bush to the specified protrusion height.
Standard protrusion height: 14.3 to 14.7 mm (0.563 to 0.579 in.)
SST 09201-10000 (09201-01050), 09950-70010 (09951-07100)

(i) Using a sharp 5.5 mm reamer, ream the guide bush to obtain the standard specified clearance between the guide bush and valve stem.

2. REPLACE EXHAUST VALVE GUIDE BUSH
(a) Heat the cylinder head to approximately 80 to 100°C (176 to 212°F).
(b) Place the cylinder head on wooden blocks.

(d) Using a caliper gauge, measure the bush bore diameter of the cylinder head.
Standard cylinder bore diameter: 10.285 to 10.306 mm (0.4049 to 0.4057 in.)
^ If the bush diameter of the cylinder head is between 10.285 to 10.306 mm (0.4049 to 0.4057 in.), proceed to the next step.
^ If the bush bore diameter of the cylinder head is 10.356 mm (0.4077 in.) or more, replace the cylinder head.
(e) Select a new guide bush (STD or O/S 0.05), and measure its diameter.
(f) Machine the bush bore diameter of the cylinder head side to the diameter of the selected guide bush.

Bush bore diameter:

(g) Heat the cylinder head to approximately 80 to 100°C (176 to 212°F).

(h) Using SST and a hammer, tap in a new guide bush to the specified protrusion height.
SST 09201-10000 (09201-01050), 09950-70010 (09951-07100)
Standard protrusion height: 14.3 to 14.7 mm (0.563 to 0.579 in.)

(i) Using a sharp 5.5 mm reamer, ream the guide bush to obtain the specified clearance between the guide bush and valve stem.

3. REPLACE RING PIN

NOTICE: It is not necessary to remove the ring pin unless it is being replaced.

(a) Remove the ring pins.
(b) Using a plastic-faced hammer, tap in new ring pins until the pin stops.

Standard protrusion:

4. REPLACE STUD BOLT

NOTICE: If a stud bolt is deformed or the threads are damaged, replace it.

(a) Remove the stud bolts.
(b) Using E6 and E8 "TORX" socket wrenches, install the stud bolts.
Torque: 9.0 N*m (92 kgf*cm, 80 in.*lbf) for stud bolts A, B, C and D