Disassembly

DISASSEMBLY





1. REMOVE VALVE LIFTERS

HINT: Arrange the valve lifters in the correct order.

2. REMOVE VALVES
a. Using SST, compress the valve spring and remove the 2 keepers.
SST 09202-70020 (09202-00010)
b. Remove the spring retainer.
c. Remove the valve spring.
d. Remove the valve.





e. Remove the using needle-nose pliers, remove the oil seal.





f. Using compressed air and a magnetic finger, remove the spring seat by blowing air.

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

INSPECTION
1. CLEAN TOP SURFACES OF PISTONS AND CYLINDER BLOCK





a. Turn the crankshaft, and bring each piston to Top Dead Center (TDC). Using a gasket scraper, remove all the carbon from the piston surface.





b. Using a gasket scraper, remove all the gasket material from the cylinder block surface.
c. Using compressed air, blow carbon and oil from the bolt holes.

CAUTION: Protect your eyes when using high pressure compressed air.

2. INSPECT CYLINDER BLOCK FOR FLATNESS
3. CLEAN CYLINDER HEAD





a. Using a gasket scraper, remove all the gasket material from the cylinder block contact surface.

NOTICE: Be careful not to scratch the cylinder block contact surface.





b. Using a wire brush, remove all the carbon from the combustion chambers.

NOTICE: Be careful not to scratch the cylinder block contact surface.





c. Using a soft brush and solvent, thoroughly clean the cylinder head.





d. Using a valve guide bushing brush and solvent, clean all the guide bushings.
4. INSPECT CYLINDER HEAD





a. Inspect for flatness.
Using a precision straight edge and a feeler gauge, measure the surface contacting the cylinder block and the manifolds for warpage.
Maximum warpage: 0.05 mm (0.0020 inch)
If warpage is greater than maximum, replace the cylinder head.





b. Inspect for cracks.
Using a dye penetrate, check the combustion chamber, intake ports, exhaust ports and cylinder block surface for cracks. If cracked, replace the cylinder head.





5. CLEAN VALVES
a. Using a gasket scraper, chip off any carbon from the valve head.
b. Using a wire brush, thoroughly clean the valve.
6. INSPECT VALVE STEMS AND GUIDE BUSHINGS





a. Using a caliper gauge, measure the inside diameter of the guide bushing.
Bushing inside diameter: 5.510 - 5.530 mm (0.2169 - 0.2177 inch)





b. Using a micrometer, measure the diameter of valve stem.





Valve stem diameter

c. Subtract the valve stem diameter measurement from the guide bushing inside diameter measurement.





Standard oil clearance





Maximum oil clearance

If the clearance is greater than maximum, replace the valve and guide bushing.
7. INSPECT VALVES





a. Check the valve is ground to the correct valve face angle.
Valve face angle: 44.5°
b. Check that the surface of the valve for wear. If the valve face is worn, replace the valve.





c. Check the valve head margin thickness.





Main thickness

If the margin thickness is less than minimum, replace the valve.





d. Check the valve overall length.





Standard overall length





Minimum overall length

If the overall length is less than minimum, replace the valve.
e. Check the surface of the valve stem tip for wear. If the valve stem tip is worn, replace the valve.
8. INSPECT AND CLEAN VALVE SEATS





a. Using a 45° carbide cutter, resurface the valve seats. Remove only enough metal to clean the seats.





b. After resurfacing the valve seat 45°, measure the residuary width of the valve seat 45°.





Minimum residuary width

If the valve seat 45° residuary width is less than minimum, replace the cylinder head.
c. Check the valve seating position.
Apply a light coat of prussian blue (or white lead) to the valve face. Lightly press the valve against the seat. Do not rotate valve.
d. Check the valve face and seat for the following:
- If blue appears 360° around the face, the valve is concentric. If not, replace the valve.
- If blue appears 360° around the valve seat, the guide and face are concentric. If not, resurface the seat.
- Check that the seat contact is in the middle of the valve face with the following width: 1.0 - 1.4 mm (0.039 - 0.055 inch)

If not, correct the valve seats as follows:





1. If the seating is too high on the valve face, use 30° and 45° cutters to correct the seat.





2. If the seating is too low on the valve face, use 60° and 45° cutters to correct the seat.





e. Hand-lap the valve and valve seat with an abrasive compound.
f. After hand-lapping, clean the valve and valve seat.

9. INSPECT VALVE SPRINGS





a. Using a steel square, measure the deviation of the valve spring.
Maximum deviation: 1.6 mm (0.063 inch)
Maximum angle (reference): 2°
If the deviation is greater than maximum, replace the valve spring.





b. Using vernier calipers, measure the free length of the valve spring.
Free length: 43.40 mm (1.7087 inch)
If the free length is not as specified, replace the valve spring.





c. Using a spring tester, measure the tension of the valve spring at the specified installed length.
Installed tension: 158.6 - 175.4 N (16.2 - 17.9 kgf, 35.7 - 39.5 lbs.) at 33.6 mm (1.323 inch)
Maximum working tension: 335.3 - 370.7 N (34.2 - 37.8 kgf, 75.4 - 83.3 lbs.) at 24.1 mm (0.949 inch)
If the installed tension is not as specified, replace the valve spring.
10. INSPECT CAMSHAFT





a. Inspect for runout.
1. Place the camshaft on V - locks.
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 maximum, replace the camshaft.





b. Inspect the cam lobes.
Using a micrometer, measure the cam lobe height.





Standard cam lobe height





Minimum cam lobe height

If the lobe height is less than minimum, replace the camshaft.





c. Inspect the camshaft journals. Using a micrometer, measure the journal diameter.





Journal diameter

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





1. Clean the bearing caps and camshaft journals.
2. Place the camshafts on the cylinder head.
3. Lay a strip of Plastigage across each of the camshaft journal.





4. Install the bearing caps.
Torque:
23 Nm (235 kgf-cm, 17 ft. lbs.) for No. 1
13 Nm (133 kgf-cm, 10 ft. lbs.) for No. 3

NOTICE: Do not turn the camshaft.

5. Remove the bearing caps.





6. Measure the Plastigage at its widest point.
Standard oil clearance: 0.035 - 0.072 mm (0.0014 - 0.0028 inch)
Maximum oil clearance: 0.10 mm (0.0039 inch)
If the oil clearance is greater than maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
7. Remove the Plastigage completely.
8. Remove the camshafts.





e. Inspect the thrust clearance.
1. Install the camshafts.
2. Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.
Standard thrust clearance: 0.040 - 0.095 mm (0.0016 - 0.0037 inch)
Maximum thrust clearance: 0.11 mm (0.0043 inch)
If the thrust clearance is greater than maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
3. Remove the camshaft.
11. INSPECT VVT TIMING SPROCKET (VALVE TIMING CONTROLLER ASSEMBLY)





a. Apply vinyl tape to all the ports except the one indicated by the arrow in the illustration.

NOTICE: Do not apply tape in the range from the tip of the camshaft to 18 mm (0.71 inch) from that tip.

b. Install the VVT timing sprocket.
Torque: 54 Nm (550 kgf-cm, 40 ft. lbs.)

NOTICE: Do not push VVT timing sprocket to the camshaft forcibly when installing it.

c. Check that the VVT timing sprocket will not turn.





d. Wind tape around the tip of the air gun and apply air of approximately 100 kPa (1 kgf/cm2, 14 psi) to the port of the camshaft.

NOTICE: When the oil splashes, wipe it off with a shop rag and the likes.

HINT: Perform this in order to release the lock pin for the maximum delay angle locking.

e. Under the condition of (d), turn the VVT timing sprocket to the advance angel side (the arrow marked direction in the illustration) with your hand.
Standard: Must turn

HINT: Depending on the air pressure, the VVT timing sprocket will turn to the advance angle side without applying force by hand. Also, under the condition that the pressure can be hardly applied because of the air leakage from the port, there may be the case that the lock pin could be hardly released.

f. Except the position where the lock pin meets at the maximum delay angle, let the VVT timing sprocket turn back and forth and check the movable range and that there is no disturbance.
Standard: Movable smoothly in the range about 30°
g. Turn the VVT timing sprocket with your hand and lock it at the maximum delay angel position.
12. 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 - 31.025 mm (1.2205 - 1.2215 inch)





b. Using a micrometer, measure the lifter diameter.
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 - 0.059 mm (0.0009 - 0.0023 inch)
Maximum oil clearance: 0.079 mm (0.0031 inch)
If the oil clearance is greater than maximum, replace the lifter. If necessary, replace the cylinder head.





13. INSPECT INTAKE MANIFOLD
Using a precision straight edge and feeler gauge, measure the surface contacting the cylinder head for warpage.
Maximum warpage: 0.10 mm (0.0039 inch)
If warpage is greater than maximum, replace the manifold.





14. INSPECT EXHAUST MANIFOLD
Using a precision straight edge and feeler gauge, measure the surface contacting the cylinder head for warpage.
Maximum warpage: 0.70 mm (0.0276 inch)
If warpage is greater than maximum, replace the manifold.





15. INSPECT CYLINDER HEAD BOLTS
Standard overall length: 156.0 - 159.0 mm (6.142 - 6.260 inch)
Maximum overall length: 159.5 mm (6.280 inch)
If the overall length is greater than maximum, replace the bolt.

REPLACEMENT
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.
SST 09201-01055, 09950-70010 (09951-07100)





c. Using a caliper gauge, measure the bushing bore diameter of the cylinder head.
d. Select the 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 the following dimension: 10.335 - 10.356 mm (0.4068 - 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.





Both 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 to the specified protrusion height.
SST 09201-01055, 09950-70010 (09951-07100)
Protrusion height: 8.7 - 9.1 mm (0.342 - 0.358 inch)





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.