Cylinder Head Assembly: Testing and Inspection

CYLINDER HEAD

INSPECTION
1. INSPECT CYLINDER HEAD SET BOLT

2. INSPECT OIL PUMP DRIVE SPROCKET
a. Wrap the chain around the drive gear.
b. Using a vernier caliper, measure the sprocket diameter with the chain.
Minimum sprocket diameter (w/chain): 48.2 mm (1.898 inch)

NOTICE: The vernier caliper must contact the chain rollers for the measurement. If the diameter is less than the minimum, replace the chain and sprocket.

3. INSPECT OIL PUMP DRIVEN SPROCKET
a. Wrap the chain around the drive shaft gear.
b. Using a vernier caliper, measure the sprocket diameter with the chain.
Minimum gear diameter (w/chain): 48.2 mm (1.898 inch)

NOTICE: The vernier caliper must contact the chain rollers for the measurement. If the diameter is less than the minimum, replace the chain and sprocket.

4. INSPECT CRANKSHAFT TIMING GEAR OR SPROCKET
a. Wrap the chain around the timing gear.
b. Using a vernier caliper, measure the timing gear diameter with the chain.
Minimum gear diameter (w/chain): 51.6 mm (2.031 inch)

NOTICE: The vernier caliper must contact the chain rollers for the measurement. If the diameter is less than the minimum, replace the chain and timing gear.

5. INSPECT CHAIN TENSIONER SLIPPER
a. Measure the tensioner slipper wear.
Maximum wear: 1.0 mm (0.039 inch)
If the wear is greater than the maximum, replace the tensioner slipper.

6. INSPECT CHAIN VIBRATION DAMPER NO. 1
a. Measure the vibration damper wear.
Maximum wear: 1.0 mm (0.039 inch)
If the wear is greater than the maximum, replace the vibration damper.

7. INSPECT CHAIN TENSIONER ASSEMBLY NO. 1
a. Check that the plunger moves smoothly when the ratchet pawl is raised.
b. Release the ratchet pawl and check that the plunger is locked in place by the ratchet pawl and does not move when pushed with your finger.

8. INSPECT CHAIN SUB-ASSEMBLY
a. Using a vernier caliper, measure the length of 15 links with the chain fully stretched.
Maximum chain elongation: 115.4 mm (4.543 inch)

NOTICE: Make the same measurements pulling at 3 or more places selected at random. Average the measurements. If the elongation is greater than the maximum, replace the chain.

9. INSPECT CAMSHAFT TIMING GEAR OR SPROCKET
a. Wrap the chain around the timing sprocket.
b. Using a vernier caliper, measure the timing sprocket diameter with the chain.
Minimum sprocket diameter (w/chain): 97.3 mm (3.831 inch)

NOTICE: The vernier caliper must contact the chain rollers for the measurement. If the diameter is less than the minimum, replace the chain and timing gear.

10. INSPECT CAMSHAFT
a. Check the camshaft for runout.
(1) Place the camshaft on V-blocks.
(2) Using a dial indicator, measure the circle runout at the center journal.
Maximum circle runout: 0.03 mm (0.0012 inch)
If the circle runout is greater than the maximum, replace the camshaft.

b. Using a micrometer, measure the cam lobe height.
Standard cam lobe height: 46.495 to 46.595 mm (1.8305 to 1.8344 inch)
Minimum cam lobe height: 46.385 mm (1.8262 inch)
If the cam lobe height is less than the minimum, replace the camshaft.

c. Using a micrometer, measure the journal diameter.
No. 1 journal diameter: 35.971 to 35.985 mm (1.4162 to 1.4167 inch)
Other journal diameter: 22.959 to 22.975 mm (0.9039 to 0.9045 inch)
If the journal diameter is not as specified, check the oil clearance.

11. INSPECT NO. 2 CAMSHAFT
a. Check the camshaft for runout.
(1) Place the camshaft on V-blocks.
(2) Using a dial indicator, measure the circle runout at the center journal.
Maximum circle runout: 0.03 mm (0.0012 inch)
If the circle runout is greater than the maximum, replace the camshaft.

b. Using a micrometer, measure the cam lobe height.
Standard cam lobe height: 45.983 to 46.083 mm (1.8104 to 1.8143 inch)
Minimum cam lobe height: 45.873 mm (1.8060 inch)
If the cam lobe height is less than the minimum, replace the camshaft.

12. INSPECT CYLINDER HEAD FOR FLATNESS
a. Using a precision straight edge and a feeler gauge, measure the surface contacting the cylinder block and the manifolds for warpage.

Maximum Warpage:

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

13. INSPECT CYLINDER HEAD FOR CRACKS
a. Using a dye penetrate, check the intake ports, exhaust ports and cylinder surface for cracks. If cracked, replace the cylinder head.

14. INSPECT VALVE SEATS

a. Apply a light coat of Prussian blue (or white lead) to the valve face.

b. Lightly press the valve face against the valve seat.
c. Check the valve face and valve seat according to this procedure.
(1) If blue appears 360° around the valve face, the valve face is concentric. If not, replace the valve.
(2) If blue appears 360° around the valve seat, the guide and valve face are concentric. If not, resurface the valve seat.
(3) Check that the valve seat contact is in the middle of the valve face with the width between 1.0 to 1.4 mm (0.039 to 0.055 inch).
15. REPAIR VALVE SEATS

NOTICE: Keep the lip free from a foreign matter.

a. If the seating is too high on the valve face, use 30° and 45° cutters to correct the seat.
b. If the seating is too low on the valve face, use 75° and 45° cutters to correct the seat.
c. Hand-lap the valve and valve seat with an abrasive compound.
d. Check the valve seating position.

16. INSPECT CAMSHAFT THRUST CLEARANCE
a. Install the camshafts.
b. Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.
Standard thrust clearance:
Intake 0.040 to 0.095 mm (0.0016 to 0.0037 inch)
Exhaust 0.080 to 0.135 mm (0.0032 to 0.0053 inch)
Maximum thrust clearance:
Intake 0.11 mm (0.0043 inch)
Exhaust 0.15 mm (0.0059 inch)
If the thrust clearance is greater than the maximum, replace the cylinder head. If the thrust surface is damaged, replace the camshaft.

17. INSPECT CAMSHAFT OIL CLEARANCE
a. Clean the bearing caps and camshaft journals.
b. Place the camshafts on the cylinder head.
c. Lay a strip of Plastigage across each of the camshaft journal.

d. Install the bearing caps.
Torque:
No. 1 bearing cap 30 Nm (306 kgf-cm, 22 ft. lbs.)
No. 2 bearing cap 30 Nm (306 kgf-cm, 22 ft. lbs.)
No. 3 bearing cap 9.0 Nm (92 kgf-cm, 80 inch lbs.)

NOTICE: Do not turn the camshaft.

e. Remove the bearing cap, and measure the Plastigage at its widest point.
Standard oil clearance:
Intake No. 1 journal bearing mark 1 0.007 to 0.038 mm (0.0028 to 0.00150 inch)
Intake No. 1 journal bearing mark 2 0.008 to 0.038 mm (0.0031 to 0.00150 inch)
Intake No. 1 journal bearing mark 3 0.008 to 0.038 mm (0.0031 to 0.00150 inch)
Other journals 0.025 to 0.062 mm (0.00098 to 0.00244 inch)
Exhaust No. 1 journal 0.040 to 0.079 mm (0.00157 to 0.00311 inch)
Other journals 0.025 to 0.062 mm (0.00098 to 0.00244 inch)
Maximum oil clearance:
Intake No. 1 journal 0.07 mm (0.0028 inch)
Other journals 0.10 mm (0.0039 inch)

NOTICE: Completely remove the Plastigage after the inspection. If the oil clearance is greater than the maximum, replace the camshaft. If necessary, replace the cylinder head.

f. If the oil clearance on the No-1 journal is greater than the maximum, choose a new bearing and install it.

Cylinder Head Journal Bore Diameter:

Standard Bearing Center Wall Thickness:

Camshaft journal diameter: 35.971 to 35-985 mm (1.41618 to 1.41673 inch)

18. INSPECT INNER COMPRESSION SPRING
a. Using a vernier caliper, measure the free length of the valve spring.
Free length: 45.7 mm (1.799 inch)
If the free length is not as specified, replace the valve spring

b. Using steel squares, measure the deviation of the valve spring.
Maximum deviation: 1.6 mm (0.063 inch)
If the deviation is greater than the maximum, replace the valve spring.

19. INSPECT INTAKE VALVE
a. Using a vernier caliper, measure the valve overall length.
Standard overall length: 101.71 mm (4.0043 inch)
Minimum overall length: 101.21 mm (3.9846 inch)
If the overall length is less than the minimum, replace the valve.

b. Using a micrometer, measure the diameter of the valve stem.
Valve stem diameter: 5.470 to 5.485 mm (0.2154 to 0.2159 inch)

c. Using a vernier caliper, measure the valve head margin thickness.
Standard margin thickness: 1.05 to 1.45 mm (0.0413 to 0.0571 inch)
Minimum margin thickness: 0.5 mm (0.0197 inch)
If the margin thickness is less than the minimum, replace the valve.

20. INSPECT EXHAUST VALVE
a. Using a vernier caliper, measure the valve overall length.
Standard overall length: 101.15 mm (3.9823 inch)
Minimum overall length: 100.70 mm (3.9646 inch)
If the overall length is less than the minimum, replace the valve.

b. Using a micrometer, measure the diameter of the valve stem.
Valve stem diameter: 5.465 to 5.480 mm (0.2152 to 0.2157 inch)

c. Using a vernier caliper, measure the valve head margin thickness.
Standard margin thickness: 1.20 to 1.60 mm (0.0470 to 0.0630 inch)
Minimum margin thickness: 0.5 mm (0.020 inch)
If the margin thickness is less than the minimum, replace the valve.

21. INSPECT INTAKE VALVE GUIDE BUSH
a. Using a caliper gauge, measure the inside diameter of the guide bush.
Bush inside diameter: 5.510 to 5.530 mm (0.2169 to 0.2177 inch)
b. Subtract the valve stem diameter measurement from the guide bush inside diameter measurement.
Standard oil clearance: 0.025 to 0.060 mm (0.0010 to 0.0024 inch)
Maximum oil clearance: 0.08 mm (0.0031 inch)
If the clearance is greater than the maximum, replace the valve and guide bush (procedure "A" and "C").

22. INSPECT EXHAUST VALVE GUIDE BUSH
a. Using a caliper gauge, measure the inside diameter of the guide bush.
Bush inside diameter: 5.510 to 5.530 mm (0.2169 to 0.2177 inch)
b. Subtract the valve stem diameter measurement from the guide bush inside diameter measurement.
Standard oil clearance: 0.030 to 0.065 mm (0.0012 to 0.0026 inch)
Maximum oil clearance: 0.10 mm (0.0039 inch)
If the clearance is greater than the maximum, replace the valve and guide bush (procedure "B" and "D").

23. REMOVE INTAKE VALVE GUIDE BUSH
a. Using SST and a hammer, tap out the guide bush (procedure "A").
SST 09201-10000 (09201-01050), 09950-70010 (09951-07100)

24. REMOVE EXHAUST VALVE GUIDE BUSH
a. Using SST and a hammer, tap out the guide bush (procedure "B").
SST 09201-10000 (09201-01050), 09950-70010 (09951-07100)
25. INSTALL INTAKE VALVE GUIDE BUSH
a. Procedure "C".
(1) Using a caliper gauge, measure the bush bore diameter of the cylinder head.
Diameter: 10.285 to 10.306 mm (0.4049 to 0.4057 inch)
(2) Install the STD bush if the diameter is within the specified diameter.
Standard diameter: 10.333 to 10.344 mm (0.4068 to 0.4072 inch)
If the diameter is not as specified, replace the STD bush.

(3) Using SST and a hammer, tap in a new guide bush to the specified protrusion height.
Protrusion height: 9.6 to 10.0 mm (0.3780 to 0.3937 inch)
SST 09201-10000 (09201-01050), 09950-70010 (09951-07100)
(4) Using a sharp 5.5mm 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 (0.00098 to 0.00236 inch)
26. INSTALL EXHAUST VALVE GUIDE BUSH
a. Procedure "D".
(1) Using a caliper gauge, measure the bush bore diameter of the cylinder head.
Diameter: 10.285 to 10.306 mm (0.4049 to 0.4057 inch)
(2) Install the STD bush if the diameter is within the specified diameter.
Standard diameter: 10.333 to 10.344 mm (0.4068 to 0.4072 inch)

(3) Using SST and a hammer, tap in a new guide bush to the specified protrusion height.
Protrusion height: 9.6 to 10.0 mm (0.3780 to 0.3937 inch)
(4) Using a sharp 5.5mm reamer, ream the guide bush to obtain the standard specified clearance between the guide bush and valve stem.
SST 09201-10000 (09201-01050), 0995070010 (09951-07100), 23801
Standard oil clearance: 0.030 to 0.065 mm (0.00118 to 0.00256 inch)

27. INSPECT VALVE LIFTER
a. Using a micrometer, measure the lifter diameter.
Lifter diameter: 30.966 to 30.976 mm (1.2191 to 1.2195 inch)

b. Using a caliper gauge, measure the lifter bore diameter of the cylinder head.
Lifter bore diameter: 31.009 to 31.025 mm (1.2208 to 1.2215 inch)
c. Subtract the lifter diameter measurement from the lifter bore diameter measurement.
Standard oil clearance: 0.033 to 0.059 mm (0.0013 to 0.0023 inch)
Maximum oil clearance: 0.07 mm (0.0028 inch)
If the oil clearance is greater than the maximum, replace the lifter. If necessary, replace the cylinder head.