Cylinder Head

CYLINDER HEAD ASSEMBLY
OVERHAUL
1. REMOVE W/HEAD STRAIGHT SCREW PLUG NO.1 (RH CYLINDER)
a. Using a straight hexagon wrench 14, remove the 2 screw plugs.
2. REMOVE W/HEAD STRAIGHT SCREW PLUG NO.2 (LH CYLINDER)
a. Using a straight hexagon wrench 14, remove the 2 screw plugs.
3. REMOVE VALVE LIFTER

HINT: Store the lifters in the correct order so that they can be returned to the original locations when reassembling.

4. REMOVE INTAKE VALVE
a. Using SST, compress the spring, then remove the 2 retainer locks, retainer, spring and valve.
SST 09202-70020 (09202-00010)

HINT: Store the valves, springs, seats and retainers in the correct order so that they can be returned to the original locations when reassembling.

5. REMOVE EXHAUST VALVE
a. Using SST, compress the spring, then remove the 2 retainer locks, retainer, spring and valve.
SST 09202-70020 (09202-00010)

HINT: Store the valves, springs, seats and retainers in the correct order so that they can be returned to the original locations when reassembling.

6. REMOVE VALVE STEM OIL O SEAL OR RING
a. Using needle-nose pliers, remove the oil seal.
7. REMOVE VALVE SPRING SEAT
8. REMOVE SEMICIRCULAR PLUG

9. INSPECT CYLINDER HEAD FOR FLATNESS
a. Using a precision straight edge and feeler gauge, measure the warpage on the surfaces which contacts the cylinder block and manifolds.
Maximum warpage:
0.05 mm (0.0020 inch) for cylinder block surface
0.10 mm (0.0039 inch) for intake manifold surface
0.10 mm (0.0039 inch) for exhaust manifold surface
If the warpage is greater than maximum, replace the cylinder head.

10. INSPECT CYLINDER HEAD FOR CRACKS
a. Using a dye penetrate, check the combustion chamber, intake ports, exhaust ports and cylinder block surface for cracks.
If cracked, replace the cylinder head.
11. INSPECT INTAKE VALVE

a. Inspect the valve overall length.
Standard overall length: 95.45 mm (3.7579 inch)
Minimum overall length: 94.95 mm (3.7382 inch)
If the overall length is less than 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. Inspect the valve head margin thickness.
Standard margin thickness: 1.0 mm (0.039 inch)
Minimum margin thickness: 0.5 mm (0.020 inch)
If the margin thickness is less than minimum, replace the valve.
12. INSPECT EXHAUST VALVE

a. Inspect the valve overall length.
Standard overall length: 95.40 mm (3.7559 inch)
Minimum overall length: 94.90 mm (3.7362 inch)
If the overall length is less than 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)

a. Using vernier calipers, measure the free length of the spring.
Free length: 45.50 mm (1.7913 inch)
If the free length is not as specified, replace the spring.

b. Using a steel square, measure the deviation of the spring.
Maximum deviation: 2.0 mm (0.079 inch)
If the deviation is greater than maximum, replace the spring.

c. Using a spring tester, measure the tension of the spring when the spring is the specified installed length.
Installed tension: 186 to 206 N (19.0 to 21.0 kgf, 41.9 to 46.3 lbs.) at 33.8 mm (1.331 inch)
If the installed tension is not as specified, replace the spring.

14. INSPECT VALVE GUIDE BUSH OIL CLEARANCE
a. Using a caliper gauge, measure the inside diameter of the valve 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 valve guide bush inside diameter measurement.
Standard oil clearance: 0.025 to 0.060 mm (0.0010 to 0.0024 inch) for intake 0.030 to 0.065 mm (0.0012 to 0.0026 inch)for exhaust
Maximum oil clearance: 0.08 mm (0.0031 inch) for intake 0.10 mm (0.0039 inch)for exhaust
If the clearance is greater than maximum, replace the valve and valve guide bush.
15. REMOVE VALVE GUIDE BUSH

a. Heat the cylinder head up to 80 to 100°C (176 to 212°F).

b. Using SST and a hammer, tap out the valve guide bush.
SST 09201-10000, 09201-01055, 09950-70010 (09951-07100)
16. INSTALL VALVE GUIDE BUSH

a. Using a caliper gauge, measure the bush bore diameter of the cylinder head.
Diameter: 10.295 to 10.313 mm (0.4053 to 0.4060 inch)
If the bush bore diameter of the cylinder head is greater than (0.313 mm (0.4060 inch), machine the bush bore to the dimension of 10.345 to 10.363 mm (0.4073 to 0.4080 inch).

HINT

Bush diameter

Bush length

b. Heat the cylinder head up to 80 to 100°C (176 to 212°F).

c. Using SST and a hammer, tap in a new valve guide bush to the specified protrusion height.
SST 09201-10000, 09201-01055, 09950-70010 (09951-07100)
Protrusion height:
11.1 to 11.5 mm (0.437 to 0.453 inch) for intake
8.9 to 9.3 mm (0.350 to 0.366 inch) for exhaust

d. Using a sharp 5.5 mm reamer, ream the valve guide bush to obtain the standard specified clearance between the valve guide bush and valve stem.
Standard oil clearance:
0.025 to 0.060 mm (0.0010 to 0.0024 inch) for intake
0.030 to 0.065 mm (0.0012 to 0.0026 inch) for exhaust
17. INSPECT VALVE SEATS
a. Apply a light coat of Prussian blue (or white lead) to the valve face.
b. Lightly press the valve against the seat.

NOTICE: Do not rotate the valve.

c. Check the valve face and seat according to the following procedure.
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 the width between 1.0 and 1.4 mm (0.039 to 0.055 inch).
18. REPAIR VALVE SEATS

NOTICE: Releasing the seat cutter pressure gradually helps to make smoother valve seat faces.

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

b. If the seating is too low on the valve face, use the 60° and 45° cutters to correct the seat.
c. Lap the valve and valve seat by hand with an abrasive compound.
d. Recheck the valve seating position.

19. 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)

20. INSPECT VALVE LIFTER OIL CLEARANCE
a. 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)
b. 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 maximum, replace the valve lifter.
^ If necessary, replace the cylinder head.
21. INSPECT CAMSHAFT GEAR BACKLASH
a. Install the camshaft timing gear.
b. Install the camshafts to the cylinder head.

NOTICE:
^ Install the camshafts with the valves and sub gear re moved.
^ Install the camshafts with their timing marks matched.

c. Set the dial indicator to the teeth of the intake camshaft at a right angle (90°).
d. Measure the backlash of the camshaft timing gear at least 4 positions.
Standard backlash: 0.020 to 0.200 mm (0.0008 to 0.0079 inch)
Maximum backlash: 0.30 mm (0.0118 inch)
22. 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 to 0.090 mm (0.0016 to 0.0035 inch)
Maximum thrust clearance: 0.12 mm (0.0047 inch)
^ If the thrust clearance is greater than maximum, replace the camshaft.
^ If necessary, replace the bearing caps and cylinder head together.
23. INSPECT CAMSHAFT OIL CLEARANCE
a. Clean the bearing caps and camshaft journals.
b. Clean the camshafts.
c. Place the camshafts on the cylinder head.

d. Lay a strip of Plastigage across each of the camshaft journals.
e. Install the bearing caps.
Torque: 16 Nm (163 kgf-cm, 12 ft. lbs.)

NOTICE: Do not turn the camshaft.

f. Remove the bearing caps.

g. Measure the Plastigage at its widest point.
Standard oil clearance:
Intake #4, #5 journals 0.025 to 0.057 mm (0.0010 to 0.0022 inch)
Other journals 0.025 to 0.062 mm (0.0010 to 0.0024 inch)
Maximum oil clearance 0.10 mm (0.0039 inch)
^ If the oil clearance is greater than maximum, re place the camshaft.
^ If necessary, replace the bearing caps and cylinder head together.

NOTICE: Completely remove the Plastigage.

24. INSTALL RING W/HEAD PIN (RH CYLINDER)
a. Using a plastic-faced hammer, tap in a new ring pin to the specified protrusion height.
Protrusion height: 3 mm (0.12 inch)

25. INSTALL RING PIN (LH CYLINDER)
a. Using a plastic-faced hammer, tap in a new ring pin to the specified protrusion height.
Protrusion height: 3 mm (0.12 inch)

26. INSTALL SPARK PLUG TUBE
a. Using paint, mark the standard height from the edge.
Standard protrusion height: 42.4 to 43.4 mm (1.669 to 1.709 inch)

HINT: Use either end of the spark plug tube.

b. Apply adhesive to the end of the spark plug tube which will be pressed into the cylinder head.
Adhesive: Part No. 08833-00070 THREE BOND 1324 or equivalent

NOTICE:
^ Install the spark plug tube within 3 minutes after applying adhesive.
^ Do not deform the spark plug tube.
^ Do not expose the spark plug tube to coolant within 1 hour after installing.

c. Using a press and wooden block, install the spark plug tube to the required protrusion height.

NOTICE: Be careful not to drip the adhesive.

27. INSTALL PCV PIPE (RH CYLINDER)
a. Using a wooden block and hammer, tap in 2 new PCV pipes until their top edges are flush with the cylinder head edge.

NOTICE: Be careful not to damage the cylinder head edge.

28. INSTALL STUD BOLT
a. Install the stud bolts on the intake side.
Torque: 7.5 Nm (76 kgf-cm, 66 inch lbs.)
29. INSTALL STUD BOLT
a. Install the stud bolts on the exhaust side.
Torque: 15 Nm (153 kgf-cm, 11 ft. lbs.)
30. INSTALL VALVE STEM OIL O SEAL OR RING

a. Apply a light coat of engine oil to the valve stem.

NOTICE: Installing the oil seals for intake and exhaust to the opposite valve guide bush may cause an improper installation.

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

b. 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.

31. INSTALL INTAKE VALVE

a. Install the valve, seat, spring, and retainer.

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

b. Using SST, compress the spring and place the 2 retainer locks around the valve stem.
SST 09202-70020 (09202-00010)

a. Install the valve, seat, spring, and retainer.

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

b. Using SST, compress the spring and place the 2 retainer locks around the valve stem.
SST 09202-70020 (09202-00010)

c. Using a plastic-faced hammer and discarded valve (the tip is wrapped with tape), lightly tap the installed valve to fit into place.

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

33. INSTALL VALVE LIFTER
a. Apply a light coat of engine oil to the valve lifter.

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

b. Install the valve lifter.
c. Check that the valve lifter is rotated smoothly by hand.
34. INSTALL SEMICIRCULAR PLUG

a. Remove any old seal packing material.
b. Apply seal packing to the plug grooves.
Seal packing: Part No. 08826-00080 or equivalent

c. Install the 2 plugs to the cylinder heads.

NOTICE:
^ Install the plugs so that they are flush with the top of the cylinder head.
^ Install the plugs within 3 minutes after applying seal packing.
^ Do not expose the seal packing to engine oil within 2 hours after installing.

35. INSTALL W/HEAD STRAIGHT SCREW PLUG NO.1 (RH CYLINDER)
a. Using a straight hexagon wrench 14, install 2 new gaskets and the 2 screw plugs.
Torque: 44 Nm (449 kgf-cm, 32 ft. lbs.)
36. INSTALL W/HEAD STRAIGHT SCREW PLUG NO.2 (LH CYLINDER)
a. Using a straight hexagon wrench 14, install 2 new gaskets and the 2 screw plugs.
Torque: 44 Nm (449 kgf-cm, 32 ft. lbs.)