Inspection and Replacement

CYLINDER HEAD

COMPONENTS:

INSPECTION
1. INSPECT CAMSHAFT OIL CLEARANCE
(a) Clean the bearing caps, camshaft housing and camshaft journals.
(b) Place the camshafts on the camshaft housing.

(c) Lay a strip of Plastigage across each of the camshaft journals.
(d) Install the camshaft bearing caps.

NOTICE: Do not turn the camshaft.

(e) Install the camshaft housing.

NOTICE: Do not turn the camshaft.

(f) Remove the camshaft bearing caps.

(g) Measure the Plastigage at its widest point.

Standard oil clearance:

Maximum oil clearance:

If the oil clearance is greater than the maximum, replace the camshaft. If necessary, replace the camshaft housing.
2. INSPECT CAMSHAFT THRUST CLEARANCE
(a) Inspect the LH side camshafts.
(1) Install the LH side camshafts.

(2) 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 greater than the maximum, replace the camshaft housing. If the thrust surface is damaged, replace the camshaft.
(b) Inspect the RH side camshafts.
(1) Install the RH side camshafts.
(2) 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 greater than the maximum, replace the camshaft housing. If the thrust surface is damaged, replace the camshaft.

3. INSPECT COMPRESSION SPRING
(a) 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.

(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.

4. INSPECT INTAKE VALVE
(a) Using a micrometer, measure the diameter of the valve stem.
Standard valve stem diameter: 5.470 to 5.485 mm (0.215 to 0.216 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 (4.17 in.)
Minimum overall length: 105.35 mm (4.15 in.)
If the overall length is less than the minimum, replace the intake valve.

5. INSPECT EXHAUST VALVE
(a) Using a micrometer, measure the diameter of the valve stem.
Standard valve stem diameter: 5.465 to 5.480 mm (0.215 to 0.216 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 (4.35 in.)
Minimum overall length: 109.90 mm (4.33 in.)
If the overall length is less than the minimum, replace the exhaust valve.

6. 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 (0.217 to 0.218 in.)
(b) Subtract the valve stem diameter measurement from the guide bush inside diameter measurement.

Standard oil clearance (Part 1):

Standard oil clearance (Part 2):

Maximum oil clearance:

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

7. 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.

8. 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.

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.

9. 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 (0.00394 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.

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 (0.405 to 0.406 in.)
If the bush bore diameter of the cylinder head is between 10.285 to 10.306 mm (0.405 to 0.406 in.), proceed to the next step.
If the bush bore diameter of the cylinder head is 10.356 mm (0.408 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:

Standard bush length: 41.3 to 41.7 mm (1.63 to 1.64 in.)

(g) 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.)

(h) Using a sharp 5.5 mm reamer, ream the guide bush to obtain the standard specified clearance between the guide bush and valve stem.
Standard oil clearance: 0.025 to 0.060 mm (0.000984 to 0.00236 in.)
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 (0.405 to 0.406 in.)
If the bush diameter of the cylinder head is between 10.285 to 10.306 mm (0.405 to 0.406 in.), proceed to the next step.
If the bush bore diameter of the cylinder head is 10.356 mm (0.408 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:

Standard bush length: 46.8 to 47.2 mm (1.84 to 1.86 in.)

(h) Using a sharp 5.5 mm reamer, ream the guide bush to obtain the specified clearance between the guide bush and valve stem.
Standard oil clearance: 0.030 to 0.065 mm (0.00118 to 0.00256 in.)

3. REPLACE SPARK PLUG TUBE

HINT: When using a new cylinder head, the spark plug tubes must be replaced.

(a) Remove the spark plug tube.
(b) Apply adhesive to the end of a new spark plug tube.
Adhesive: Toyota Genuine Adhesive 1324, Three Bond 1324 or equivalent.
Standard seal diameter: 15 mm (0.591 in.)

NOTICE:
^ Install the spark plug tube within 3 minutes after applying adhesive.
^ Be careful not to deform the spark plug tube.
^ Be careful not to expose the seal to coolant for at least 1 hour after installing it.

(c) Using a wooden block and hammer, tap in the spark plug tube to the specified protrusion height.
Standard protrusion height: 75.1 to 76.1 mm (2.96 to 3.00 in.)

NOTICE: To avoid tapping in the spark plug tube too far, measure the protrusion height while tapping it.

4. 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 to the cylinder head.

Inspection and Replacement

COMPONENTS:

Standard oil clearance:

Maximum oil clearance:

Standard oil clearance (Part 1):

Standard oil clearance (Part 2):

Maximum oil clearance:

Standard warpage:

Bush bore diameter:

Bush bore diameter:

Standard protrusion: