Disassembly

Part 1 Of 4:

Part 2 Of 4:

Part 3 Of 4:

Part 4 Of 4:

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) 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. REMOVE GASKET MATERIAL
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.





3. CLEAN COMBUSTION CHAMBERS
Using a wire brush, remove all the carbon from the combustion chambers.

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





4. CLEAN CYLINDER HEAD
Using a soft brush and solvent, thoroughly clean the cylinder head.





5. CLEAN VALVE GUIDE BUSHINGS
Using a valve guide bushing brush and solvent, clean all the guide bushings.





6. INSPECT FOR FLATNESS
Using a precision straight edge and 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.





7. INSPECT FOR CRACKS
Using a dye penetrant, check the combustion chamber, intake ports, exhaust ports and cylinder block surface for cracks. If cracked, replace the cylinder head.





8. CLEAN VALVES
a) Using a gasket scraper, chip off any carbon from the valve head.
b) Using a wire brush, thoroughly clean the valve.





9. INSPECT VALVE STEMS AND GUIDE BUSHINGS
a) Using a caliper gauge, measure the inside diameter of the guide bushing.
Bushing inside diameter: 5.010 - 5.030 mm (0.19724 - 0.19803 inch)





b) Using a micrometer, measure the diameter of the valve stem.
Valve stem diameter:
Intake 4.970 - 4.985 mm (0.19567 - 0.19626 inch)
Exhaust 4.965 - 4.980 mm (0.19547 - 0.19606 inch)
c) Subtract the valve stem diameter measurement from the guide bushing inside diameter measurement.
Standard oil clearance:
Intake 0.025 - 0.060 mm (0.00098 - 0.00236 inch)
Exhaust 0.030 - 0.065 mm (0.00118 - 0.00256 inch)
Maximum oil clearance:
Intake 0.08 mm (0.0031 inch)
Exhaust 0.10 mm (0.0039 inch)
If the clearance is greater than maximum, replace the valve and guide bushing.





10. 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.
Standard margin thickness: 1.00 - 1.15 mm (0.0393 - 0.0453 inch)
Minimum margin thickness: 0.7 mm (0.028 inch)
If the margin thickness is less than minimum, replace the valve.





d) Check the valve overall length.
Standard overall length:
Intake 89.25 mm (3.5138 inch)
Exhaust 87.90 mm (3.4606 inch)
Minimum overall length:
Intake 88.75 mm (3.4941 inch)
Exhaust 87.40 mm (3.4409 inch)
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.





11. INSPECT AND CLEAN VALVE SEATS
a) Using a 45° carbide cutter, resurface the valve seats. Remove only enough metal to clean the seats.





b) 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.
c) 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. It 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 20° and 45° cutters to correct the seat.





2) If the seating is too low on the valve face, use 75° and 45° cutters to correct the seat.





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





12. 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: 45.1 mm (1.776 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:
149 - 165 N (15.2 - 16.8 kgf, 33.5 - 37.1 lbs.) at 32.5 mm (1.280 inch)
Maximum working tension:
286 - 316 N (29.1 - 32.2 kgf, 64.2 - 71.0 lbs. at 23.9 mm (0.941 inch)
If the installed tension is not as specified, replace the valve spring





13. INSPECT CAMSHAFT FOR RUNOUT
a) Place the camshaft on V-blocks.
b) 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.





14. INSPECT CAM LOBES
Using a micrometer, measure the cam lobe height.
Standard cam lobe height:
Intake 44.617 - 44.717 mm (1.75657 - 1.76051 inch)
Exhaust 44.666 - 44.766 mm (1.75850 - 1.76244 inch)
Minimum cam lobe height:
Intake 44.47 mm (1.7508 inch)
Exhaust 44.52 mm (1.7528 inch)
If the cam lobe height is less than minimum, replace the camshaft.





15. INSPECT CAMSHAFT JOURNALS
Using a micrometer, measure the journal diameter.
No.1 journal diameter:
34.449 - 34.465 mm (1.35626 - 1.35689 inch)
Others journal diameter:
22.949 - 22.965 mm (0.90350 - 0.90413 inch)
If the journal diameter is not as specified, check the oil clearance.





16. INSPECT CAMSHAFT JOURNAL 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 23 Nm (235 kgf-cm, 17 ft. lbs.)
No.2 12.7 Nm (130 kgf-cm, 10 ft. lbs.)

NOTICE: Do not turn the camshaft.

e) Remove the bearing caps.





f) Measure the plastigage at its widest point.
Standard oil clearance:
0.040 - 0.095 mm (0.00157 - 0.00374 inch)
Maximum oil clearance:
0.115 mm (0.00453 inch)
If the oil clearance is greater than maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
g) Completely remove the Plastigage.
h) Remove the camshafts.





17. 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:
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.
c) Remove the camshafts.





18. 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 (1.22047 - 1.22145 inch)





b) Using a micrometer, measure the lifter diameter.
Lifter diameter:
30.966 - 30.976 mm (1.21913 - 1.21953 inch)
c) Subtract the lifter diameter measurement from the lifter bore diameter measurement.
Standard oil clearance:
0.024 - 0.059 mm (0.00094 - 0.00232 inch)
Maximum oil clearance:
0.1 mm (0.004 inch)
If the oil clearance is greater than maximum, replace the lifter.
If necessary, replace the cylinder head.





19. 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.





20. 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.

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 9.706 mm (0.38213 inch), machine the bushing bore to the following dimension: 9.735 - 9.756 mm (0.38327 - 0.38493 inch)
If the bushing bore diameter of the cylinder head is greater than 9.756 mm (0.38493 inch), replace the cylinder head.
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: 9.0 - 9.4 mm (0.354 - 0.370 inch)





g) Using a sharp 5 mm reamer, ream the guide bushing to obtain the standard specified clearance between the guide bushing and valve stem.