Part 2

11. Inspect camshaft timing tube.

HINT:
- There are 2 sizes of the camshaft timing tube journal diameter, green and red marks accordingly. The mark is on the face of the camshaft timing tube.
When replacing the timing tube, select a new timing tube according to the mark on the cylinder head.

Cylinder head: Mark A
Camshaft timing tube: Green mark
Cylinder head: Mark B
Camshaft timing tube: Red mark





a. Using a micrometer, measure the journal diameter.





If the journal diameter is not as specified, check the oil clearance.





b. Install the timing tube to the intake camshaft, and check the timing tube turn smoothly.
If necessary, replace the timing tube and intake camshaft.





12. Inspect camshaft gear spring.
Using vernier calipers, measure the free distance between the spring ends.

Free distance: 18.2 - 18.8 mm (0.712 - 0.740 inch)

If the free distance is not as specified, replace the gear spring.
13. Inspect camshaft bearings.
Check that bearings for flaking and scoring. If the bearings are damaged, replace the bearing caps and cylinder head as a set.





14. Inspect camshaft and camshaft timing tube journal oil clearance.
a. Install the camshaft timing tube to the intake camshaft.
b. Clean the bearing caps and journals.
c. Place the camshafts on the cylinder head.
d. Lay a strip of Plastigage across each of the journals.





e. Install the bearing caps.

NOTICE: Do not turn the camshaft.

f. Remove the bearing caps.





g. Measure the Plastigage at its widest point.








If the oil clearance is greater than maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
h. Completely remove the Plastigage
i. Remove the camshafts.
j. Remove the camshaft timing tube from the intake camshaft.





15. Inspect camshaft thrust clearance.
a. Install the camshaft timing tube to the intake camshaft.
b. Install the camshaft.
c. Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.





If the thrust clearance is greater than maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
d. Remove the camshafts.
e. Remove the camshaft timing tube from the intake camshaft.





16. Inspect camshaft gear backlash.
a. Install the drive gear to the camshaft timing tube.
b. Install the camshaft timing tube to the intake camshaft.
c. Install the camshafts without installing the exhaust camshaft sub-gear and front bearing cap.
d. Using a dial indicator, measure the backlash.

Standard backlash: 0.020 - 0.200 mm (0.0008 - 0.0079 inch)
Maximum backlash: 0.30 mm (0.0188 inch)

If the backlash is greater than maximum, replace the Intake camshaft drive gear and exhaust camshaft.
e. Remove the camshafts.
f. Remove the camshaft timing tube from the intake camshaft.
g. Remove the drive gear from the camshaft timing tube.





17. Inspect valve lifters and lifter bores.
a. Using a caliper gauge, measure the lifter bore diameter of the cylinder head.

Lifter bore diameter: 31.000 - 31.016 mm (1.2205 - 1.2211 inch)





b. Using a micrometer, measure the lifter diameter at the 12.5 ± 2.0 mm (0.492 ± 0.079 inch) from the top surface.

Lifter diameter: 30.966 - 30.976 mm (1.2191 - 1.2195 inch)

c. Subtract the lifter diameter measurement from the lifter bore diameter measurement.

Standard oil clearance: 0.024 - 0.050 mm (0.0009 - 0.0020 inch)
Maximum oil clearance: 0.07 mm (0.0028 inch)

If the oil clearance is greater than maximum, replace the lifter.
If necessary, replace the cylinder head.





18. Inspect upper intake manifold.
Using a precision straight edge and feeler gauge, measure the surface contacting the lower intake manifold for warpage.

Maximum warpage: 0.15 mm (0.0059 inch)

If warpage is greater than maximum, replace the upper intake manifold.





19. Inspect lower intake manifold.
Using a precision straight edge and feeler gauge, measure the surface contacting the cylinder head and upper intake manifold for warpage.

Maximum warpage: 0.15 mm (0.0059 inch)

If warpage is greater than maximum, replace the lower intake manifold.





20. Inspect exhaust manifold.
Using a precision straight edge and feeler gauge, measure the surface contacting the cylinder head for warpage.

Maximum warpage: 0.50 mm (0.0197 inch)

If warpage is greater than maximum, replace the manifold.


REPLACEMENT



1. Replace valve guide bushings.
a. Gradually heat the cylinder head to 80 - 100°C (176 - 212°F).




b. Using SST and a hammer, tap out the guide bushing.
Special Service Tool (SST) 09201-01055, 09950 - 70010 (09951 - 07100)





c. Using a caliper gauge, measure the bushing bore diameter of the cylinder head.





d. Select a new guide bushing (STD or O/S 0.05). If the bushing bore diameter of the cylinder head is greater than 10.306 mm (0.4057 inch), machine the bushing bore to this dimension:

O/S bushing bore: 10.335 - 10.356 mm (0.4069 - 0.4077 inch)

If the bushing bore diameter of the cylinder head is greater than 10.356 mm (0.4077 inch), replace the cylinder head.





HINT: Different the bushings are used for the intake and exhaust.





e. Gradually heat the cylinder head to 80 - 100°C (176 - 212°F).





f. Using SST and a hammer, tap in a new guide bushing the specified protrusion height.
SST: 09201-01055, 09950-70010 (09951-07100)





g. Using a sharp 5.5 mm reamer, ream the guide bushing to obtain the standard specified clearance between the guide bushing and valve stem.





2. Replace spark plug tube gaskets.
a. Bend the 4 ventilation case claws installed on the cylinder head cover to an angle of 90� or more.
b. Using a screwdriver, pry out the gasket.

NOTICE: Be careful not to damage the cylinder head cover. Tape the screwdriver tip.





c. Using SST and a hammer, tap in a new gasket until its surface is flush with the upper edge of the cylinder head cover.
SST: 09950-60010 (09551-00240, 09951 - 00440, 09952 - 06010), 09950 - 70010 (09951 -07100)

NOTICE: Be careful of the installation direction.

d. Apply a light coat of MP grease to the gasket lip.
e. Return the 4 ventilation case claws to its original position.


REASSEMBLY

HINT:
- Thoroughly clean all parts to be assembled.
- Before installing the parts, apply new engine oil to all sliding and rotating surfaces.
- Replace all gaskets and oil seals with new ones.





1. Install spark plug tubes.

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

a. Apply adhesive to the end of the spark plug tube.

Adhesive: Part No. 08833-00070, THREE BOND 1324 or equivalent





b. Using a wooden block and hammer, tap in a new spark tube until there is 48.4 - 49.6 mm (1.906 - 1.953 inch) protruding from the camshaft bearing cap installation surface of the cylinder head.

NOTICE: Avoid tapping a new spark plug tube in too far by measuring the amount of the protrusion while tapping.





2. Install valves.
a. Using Special Service Tool (SST), push in a new oil seal.
SST: 09201-41020





HINT: The intake valve oil seal is brown and the exhaust valve oil seal is gray.





b. Install these parts:
1) Valve
2) Spring Seat
3) Valve spring
4) Spring retainer





c. Using SST, compress the valve spring and place the 2 keepers around the valve stem.
SST: 09202-70020 (09202-70010)





d. Using a plastic-faced hammer and the valve stem (not in use) tip wound with vinyl tape, lightly tap the valve stem tip to assure proper fit.

NOTICE: Be careful not do damage the valve stem tip.

3. Install valve lifters and shims.
a. Install the valve lifter and shim.
b. Check that the valve lifter rotates smoothly by hand.































DISASSEMBLY

1. Remove valve lifters and shims.

HINT: Arrange the valve lifters and shims in correct order.





2. Remove valves.
a. Using Special Service Tool (SST), compress the valve spring and remove the 2 keepers.
SST 09202 - 70020 (09202 - 00010)
b. Remove these parts:
- Spring retainer
Valve spring
- Valve
Spring seat

HINT: Arrange the valves, valve springs, spring seats and spring retainers incorrect order.





c. Using needle-nose pliers, remove the oil seal.