Part 2

OVERHAUL (CONTINUED)

16. INSPECT EXHAUST VALVE SEAT
a. Using a 45° carbide cutter, resurface the valve seats, move only enough metal to clean the seats.

b. Check the valve seating position.
1. Apply a light coat of Prussian blue (or white lead) to the valve face.
2. Lightly press the valve against the seat. Do not rotate valve.
c. Check the valve face and seat for the following:
1. If blue appears 360° around the face, the valve is concentric. If not, replace the valve.
2. If blue appears 360° around the valve seat, the guide and face are concentric. If not, resurface the seat.
3. Check that the seat contact is in the middle of the valve face with these width:
Width: 1.0 to 1.4 mm (0.039 to 0.055 inch)

If not, correct the exhaust valve seats as follows:
d. If the seating is too high on the valve face: Use 30° and 45° cutters to correct the seat.

e. If the seating is too low on the valve face: Use 60° and 45° cutters to correct the seat.

f. Handrub the valve and valve seat with an abrasive compound.
g. After handrubbing, clean the valve and valve seat.

17. INSPECT VALVE LIFTER
a. Using a micrometer, measure the lifter diameter at the 10.5 to 14.5 mm (0.413 to 0.570 inch) from the top surface.
Lifter diameter: 30.968 to 30.976 mm (1.2192 to 1.2195 inch)
If the lifter diameter is not as specified, check the oil clearance.

b. Using a caliper gauge, measure the lifter bore diameter of the cylinder head.
Lifter bore diameter: 31.000 to 31.016 mm (1.2205 to 1.2211 inch)
If the lifter diameter is not as specified, check the oil clearance.
c. Subtract the lifter diameter measurement from the lifter bore diameter measurement.
Standard oil clearance: 0.024 to 0.048 mm (0.0009 to 0.0018 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.

18. INSPECT CAMSHAFT
a. Inspect the circle runout.
1. Place the camshaft on V-blocks.
2. Using a dial indicator, measure the circle runout at the center journal.
Maximum circle runout: 0.08 mm (0.0031 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: 42.610 to 42.710 mm (1.6776 to 1.6815 inch)
Minimum cam lobe height: 42.46 mm (1.6717 inch)
If the cam lobe height is less than the minimum, replace the camshaft.

c. Inspect the journal diameter of the camshaft.
1. Using a micrometer, measure the journal diameter of the camshaft for the camshaft bearing.
Journal diameter: 26.954 to 26.970 mm (1.0612 to 1.0618 inch)
If the journal diameter is not as specified, check the oil clearance.

2. Using a micrometer, measure the journal diameter for the camshaft timing tube.
Journal diameter: 30.984 to 31.000 mm (1.2198 to 1.2205 inch)
If the journal diameter is not as specified, check the oil clearance.

d. Inspect the journal diameter of the camshaft timing tube.
1. Using a micrometer, measure the journal diameter.
Journal diameter: 39.955 to 39.964 mm (1.5730 to 1.5734 inch)
If the journal diameter is not as specified, check the oil clearance.

e. Install the camshaft timing tube to the camshaft, and check that the timing tube turn smoothly.
If necessary, replace the timing tube and camshaft.

f. Check the oil clearance.
1. Install the camshaft timing tube to the camshaft.
2. Clean the bearing caps and journals.
3. Check that bearings for flaking and scoring.
If the bearings are damaged, replace the bearing caps and cylinder head as a set.
4. Place the camshaft on the cylinder head.
5. Lay a strip of Plastigage across each of the journals.

6. Install the bearing caps.

NOTICE: Do not turn the camshaft.

7. Remove the bearing caps.
8. 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 and timing tube. If necessary, replace the bearing caps and cylinder head as a set.
9. Completely remove the Plastigage.
10. Remove the camshaft.
11. Remove the camshaft timing tube from the camshaft.

g. Check the thrust clearance.
1. Install the camshaft timing tube to the camshaft.
2. Install the camshaft.
3. Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.
Standard thrust clearance: 0.060 to 0.100 mm (0.0024 to 0.0039 inch)
Maximum thrust clearance: 0.13 mm (0.0051 inch)
If the thrust clearance is greater than maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
4. Remove the camshaft.
5. Remove the camshaft timing tube from the camshaft.

h. Check the gear backlash.
1. Install the drive gear to the camshaft timing tube.
2. Install the camshaft timing tube to the camshaft.
3. Install the camshaft and No. 2 camshaft without installing the camshaft sub-gear and front bearing cap.
4. Using a dial indicator, measure the backlash.
Standard backlash: 0.020 to 0.200 mm (0.0008 to 0.0079 inch)
Maximum backlash: 0.30 mm (0.0118 inch)
If the backlash is greater than the maximum, replace the drive gear and No. 2 camshaft.
i. Remove the camshaft and No. 2 camshaft.
j. Remove the camshaft timing tube from the camshaft.
k. Remove the drive gear from the camshaft timing tube.

19. INSPECT NO.2 CAMSHAFT
a. Inspect the circle runout.
1. Place the camshaft on V-blocks.
2. Using a dial indicator, measure the circle runout at the center journal.
Maximum circle runout: 0.08 mm (0.0031 inch)
If the circle runout is greater than the maximum, replace the No. 2 camshaft.

b. Using a micrometer, measure the cam lobe height.
Standard cam lobe height: 42.630 to 42.730 mm (1.6783 to 1.6823 inch)
Minimum cam lobe height: 42.48 mm (1.6724 inch)
If the cam lobe height is less than the minimum, replace the No. 2 camshaft.

c. Using a micrometer, measure the journal diameter.
Journal diameter: 26.954 to 26.970 mm (1.0612 to 1.0618 inch)
If the journal diameter is not as specified, check the oil clearance.

d. Check the oil clearance.
1. Clean the bearing caps and journals.
2. Check that bearings for flaking and scoring. If the bearings are damaged, replace the bearing caps and cylinder head as a set.
3. Place the No. 2 camshaft on the cylinder head.
4. Lay a strip of Plastigage across each of the journals.
5. Install the bearing caps.

NOTICE: Be careful not to turn the No. 2 camshaft.

6. Remove the bearing caps.

7. Measure the Plastigage at its widest point.
Standard oil clearance: 0.030 to 0.067 mm (0.0012 to 0.0026 inch)
Maximum oil clearance: 0.100 mm (0.0039 inch)
If the oil clearance is greater than maximum, replace the No. 2 camshaft. If necessary, replace the bearing caps and cylinder head as a set.
8. Completely remove the Plastigage.
9. Remove the No. 2 camshaft.

e. Check the thrust clearance.
1. Install the camshaft.
2. Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.
Standard thrust clearance: 0.030 to 0.075 mm (0.0012 to 0.0030 inch)
Maximum thrust clearance: 0.12 mm (0.0047 inch)
If the thrust clearance is greater than the maximum, replace the No. 2 camshaft. If necessary, replace the bearing caps and cylinder head as a set.
3. Remove the No. 2 camshaft.

20. INSPECT NO.3 CAMSHAFT SUB-ASSEMBLY
a. Inspect the circle runout.
1. Place the camshaft on V-blocks.
2. Using a dial indicator, measure the circle runout at the center journal.
Maximum circle runout: 0.08 mm (0.0031 inch)
If the circle runout is greater than the maximum, replace the No. 3 camshaft.

c. Inspect the journal diameter of the camshaft.
1. Using a micrometer, measure the journal diameter of the No. 3 camshaft for the camshaft bearing.
Journal diameter: 26.954 to 26.970 mm (1.0612 to 1.0618 inch)
If the journal diameter is not as specified, check the oil clearance.

e. Install the timing tube to the No. 3 camshaft, and check the timing tube turn smoothly.
If necessary, replace the timing tube and No. 3 camshaft.

f. Check the oil clearance.
1. Install the camshaft timing tube to the No. 3 camshaft.
2. Clean the bearing caps and journals.
3. Check that bearings for flaking and scoring.
If the bearings are damaged, replace the bearing caps and cylinder head as a set.
4. Place the No. 3 camshaft on the cylinder head.
5. Lay a strip of Plastigage across each of the journals.
6. Install the bearing caps.

NOTICE: Be careful not to turn the camshaft.

7. Remove the bearing caps.

8. Measure the Plastigage at its widest point.

Standard oil clearance

Maximum oil clearance

If the oil clearance is greater than the maximum, replace the No. 3 camshaft and timing tube. If necessary, replace the bearing caps and cylinder head as a set.
9. Completely remove the Plastigage.
10. Remove the camshaft.
11. Remove the camshaft timing tube from the No. 3 camshaft.

g. Check the thrust clearance.
1. Install the camshaft timing tube to the No. 3 camshaft.
2. Install the No. 3 camshaft.
3. Using a dial indicator, measure the thrust clearance while moving the No. 3 camshaft back and forth.
Standard thrust clearance: 0.060 to 0.100 mm (0.0024 to 0.0039 inch)
Maximum thrust clearance: 0.13 mm (0.0051 inch)
If the thrust clearance is greater than the maximum, replace the No. 3 camshaft. If necessary, replace the bearing caps and cylinder head as a set.
4. Remove the No. 3 camshaft.
5. Remove the camshaft timing tube from the No. 3 camshaft.

h. Check the gear backlash.
1. Install the drive gear to the camshaft timing tube.
2. Install the camshaft timing tube to the No. 3 camshaft.
3. Install the No. 3 camshaft and No. 4 camshaft without installing the camshaft sub-gear and front bearing cap.
4. Using a dial indicator, measure the backlash.
Standard backlash: 0.020 to 0.200 mm (0.0008 to 0.0079 inch)
Maximum backlash: 0.30 mm (0.0188 inch)
If the backlash is greater than the maximum, replace the drive gear and No. 4 camshaft.
i. Remove the No. 3 camshaft and No. 4 camshaft.
j. Remove the camshaft timing tube from the No. 3 cam shaft.
k. Remove the drive gear from the camshaft timing tube.

21. INSPECT NO. 4 CAMSHAFT SUB-ASSEMBLY
a. Inspect the circle runout.
1. Place the camshaft on V-blocks.
2. Using a dial indicator, measure the circle runout at the center journal.
Maximum circle runout: 0.08 mm (0.0031 inch)
If the circle runout is greater than the maximum, replace the No. 4 camshaft.

c. Using a micrometer, measure the journal diameter.
Journal diameter: 26.954 to 26.970 mm (1.0612 to 1.0618 inch)
If the journal diameter is not as specified, check the oil clearance.

d. Check the oil clearance.
1. Clean the bearing caps and journals.
2. Check that bearings for flaking and scoring. If the bearings are damaged, replace the bearing caps and cylinder head as a set.
3. Place the No. 4 camshaft on the cylinder head.
4. Lay a strip of Plastigage across each of the journals.
5. Install the bearing caps.

NOTICE: Be careful not to turn the No. 4 camshaft.

6. Remove the bearing caps.

7. Measure the Plastigage at its widest point.
Standard oil clearance: 0.030 to 0.067 mm (0.0012 to 0.0026 inch)
Maximum oil clearance: 0.100 mm (0.0039 inch)
If the oil clearance is greater than the maximum, replace the No. 4 camshaft. If necessary, replace the bearing caps and cylinder head as a set.
8. Completely remove the Plastigage.
9. Remove the No. 4 camshaft.

e. Check the thrust clearance.
1. Install the camshaft.
2. Using a dial indicator, measure the thrust clearance while moving the No. 4 camshaft back and forth.
Standard thrust clearance: 0.030 to 0.075 mm (0.0012 to 0.0030 inch)
Maximum thrust clearance: 0.12 mm (0.0047 inch)
If the thrust clearance is greater than the maximum, replace the No. 4 camshaft.
If necessary, replace the bearing caps and cylinder head as a set.
3. Remove the No. 4 camshaft.

22. INSPECT CYLINDER HEAD SET BOLT
a. Using a vernier caliper, measure the thread outside diameter of the bolt.
Standard outside diameter: 9.770 to 9.960 mm (0.3846 to 0.3921 inch)
Minimum outside diameter: 9.70 mm (0.3819 inch)
If the diameter is less than minimum, replace the bolt.

23. INSTALL SPARK PLUG TUBE

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

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.

b. Using a wooden block and hammer, tap in a new spark tube until there is 48.4 to 49.6 mm (1.906 to 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 protrusion length while tapping.

24. INSTALL TIGHT PLUG NO.1
a. Apply adhesive to the end of the spark plug tube.
Adhesive: Part No. 08833-00070, THREE BOND 1324 or equivalent
b. Using SST and a hammer, tap in a new tight plug as shown in the illustration.
SST 09550-60010 (09551-00200), 09950-70010 (09951-07100)

25. INSTALL RING W/HEAD PIN

26. INSTALL STUD BOLT

27. INSTALL VALVE STEM OIL SEAL
a. Using SST, push in a new oil seal.
SST 09201-41020

NOTICE: Failure to use SST will cause the seal to be damaged or improperly seated.

b. Apply a light coat of engine oil on a new oil seal.

NOTICE: Pay close attention when installing the intake and exhaust oil seals. For example, installing the intake oil seal into the exhaust or installing the exhaust oil seal to the intake can cause installation problems later.

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

28. INSTALL INTAKE VALVE
a. Install the valve, spring seat, compression spring and spring retainer.
b. Using SST, compress the compression spring and place the 2 keepers around the valve stem.

29. INSTALL EXHAUST VALVE
a. Install the valve, spring seat, compression spring and spring retainer.

NOTICE: Install the same parts in the same combination to the original locations.

b. Using SST, compress the compression spring and place the 2 keepers around the valve stem.

c. Using a plastic-faced hammer and a discarded valve with its tip wrapped in tape, lightly tap the installed valve to ensure that it is securely fit.

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

30. INSTALL VALVE LIFTER
a. Install the valve lifter and shim.
b. Check that the valve lifter rotates smoothly by hand.