Cylinder Head Overhaul
CYLINDER HEAD ASSY
OVERHAUL
1. REMOVE W/ HEAD TAPER SCREW PLUG NO.1
a. Using a 10 mm socket hexagon wrench, remove the taper screw plug and the gasket.
2. REMOVE VALVE LIFTER
HINT: Keep the valve lifters in correct order so they can be returned to the original locations when re-assembling.
3. REMOVE OIL CONTROL VALVE FILTER
a. Using an 8 mm hexagon wrench, remove the taper screw plug.
b. Remove the filter and gasket.
4. REMOVE INTAKE VALVE
a. Using SST, compress the valve spring and remove the 2 retainer locks, retainer, and valve spring.
SST 09202-70020 (09202-00010)
HINT: Keep the valves, valve springs, spring seats and spring retainers in correct order so they can be returned to the original locations when re-assembling.
5. REMOVE EXHAUST VALVE
a. Using SST, compress the valve spring and remove the 2 retainer locks, retainer, and valve spring.
SST 09202-70020 (09202-00010)
HINT: Keep the valves, valve springs, spring seats and spring retainers in correct order so they can be returned to the original locations when re-assembling.
6. REMOVE VALVE STEM OIL O-SEAL OR RING
a. Using needle-nose pliers, remove the oil seal.
7. REMOVE VALVE SPRING SEAT
a. Using a compressed air and a magnetic finger, remove the valve spring seats.
8. REMOVE UNION
9. REMOVE STUD BOLT
a. Using Torx socket wrench E5 and E7, remove the 7 stud bolts.
10. REMOVE CAMSHAFT BEARING CAP SETTING RING PIN
11. INSPECT CYLINDER HEAD FOR FLATNESS
a. Using a precision straight edge and a feeler gauge, measure the surface contacting the cylinder block and the manifolds for warpage.
Maximum warpage:
Cylinder block surface 0.05 mm (0.0020 inch)
Intake manifold surface 0.10 mm (0.0039 inch)
Exhaust manifold surface 0.10 mm (0.0039 inch)
12. INSPECT CYLINDER HEAD FOR CRACKS
a. Using a dye penetrate, check the combustion chamber, intake ports, exhaust ports and cylinder block surface for cracks.
13. INSPECT INTAKE VALVE
a. Check the valve overall length.
Standard overall length: 89.25 mm (3.5138 inch)
Minimum overall length: 88.75 mm (3.4941 inch)
b. Using a micrometer, measure the diameter of the valve stem.
Valve stem diameter: 4.970 to 4.985 mm (0.1957 to 0.1963 inch)
c. Check the valve head margin thickness.
Standard margin thickness: 1.0 mm (0.039 inch)
Minimum margin thickness: 0.5 mm (0.020 inch)
14. INSPECT EXHAUST VALVE
a. Check the valve overall length.
Standard overall length: 87.90 mm (3.4606 inch)
Minimum overall length: 87.40 mm (3.4409 inch)
b. Using a micrometer, measure the diameter of the valve stem.
Valve stem diameter: 4.965 to 4.980 mm (0.1955 to 0.1961 inch)
c. Check the valve head margin thickness.
Standard margin thickness: 1.15 mm (0.045 inch)
Minimum margin thickness: 0.5 mm (0.020 inch)
15. INSPECT OUTER COMPRESSION SPRING
a. Using vernier calipers, measure the free length of the valve spring.
Free length: 45.1 mm (1.776 inch)
b. Using a steel square, measure the deviation of the valve spring.
Maximum deviation: 1.6 mm (0.063 inch)
Maximum angle (reference): 2°
c. Using a spring tester, measure tension of the valve spring at the specified installed length.
Installed tension: 149 to 165 N (15.2 to 16.8 kgf, 33.5 to 37.1 lbs) at 32.5 mm (1.280 inch)
Maximum working tension: 286 to 316 N (29.1 to 32.2 kgf, 64.2 to 71.0 lbs) at 23.9 mm (0.941 inch)
If the installed tension is not as specified, replace the valve spring.
16. INSPECT VALVE GUIDE BUSHING OIL CLEARANCE
a. Using a caliper gauge, measure the inside diameter of the guide bushing.
Bushing inside diameter: 5.010 to 5.030 mm (0.1972 to 0.1980 inch)
b. Subtract the valve stem diameter measurement from the guide bushing inside diameter measurement
Standard oil clearance:
Intake 0.025 to 0.060 mm (0.0010 to 0.0024 inch)
Exhaust 0.030 to 0.065 mm (0.0012 to 0.0026 inch)
Maximum oil clearance:
Intake 0.08 mm (0.0032 inch)
Exhaust 0.10 mm (0.0039 inch)
17. REMOVE INTAKE VALVE GUIDE BUSH
a. Heat the cylinder head to 80 to 100°C (176 to 212°F)
b. Using SST and a hammer, tap out the guide bushing.
SST 09201-10000 (09201-01050), 09950-70010 (09951-07100)
18. REMOVE EXHAUST VALVE GUIDE BUSH
a. Heat the cylinder head to 80 to 100°C (176 to 212°F).
b. Using SST and a hammer, tap out the guide bushing.
SST 09201-10000 (09201-01050), 09950-70010 (09951-07100)
19. INSTALL INTAKE VALVE GUIDE BUSH
a. Using a caliper gauge, measure the bushing bore diameter of the cylinder head.
Diameter: 9.685 to 9.706 mm (0.3813 to 0.3821 inch)
If the bushing bore diameter of the cylinder head is greater than 9.706 mm (0.3821 inch), machine the bushing bore to the dimension of 9.735 to 9.755 mm (0.3833 to 0.3841 inch).
HINT
b. Heat the cylinder head to 80 to 100°C (176 to 212°F).
c. Using SST and a hammer, tap in a new guide bushing to the specified protrusion height.
SST 09201-10000 (09201-01050), 09950-70010 (09951-07100)
Protrusion height: 9.0 to 9.4 mm (0.354 to 0.370 inch)
d. Using a sharp 5 mm reamer, ream the guide bushing to obtain the standard specified clearance between the guide bushing and the valve stem
Standard oil clearance: 0.025 to 0.060 mm (0.0010 to 0.0024 inch)
20. INSTALL EXHAUST VALVE GUIDE BUSH
a. Using a caliper gauge, measure the bushing bore diameter of the cylinder head.
Diameter: 9.685 to 9.706 mm (0.3813 to 0.3821 inch)
If the bushing bore diameter of the cylinder head is greater than 9.706 mm (0.3821 inch), machine the bushing bore to the dimension of 9.735 to 9.755 mm (0.3833 to 0.3841 inch).
HINT
b. Heat the cylinder head to 80 to 100°C (176 to 212°F).
c. Using SST and a hammer, tap in a new guide bushing to the specified protrusion height.
SST 09201-10000 (09201-01050), 09950-70010 (09951-07100)
Protrusion height: 9.0 to 9.4 mm (0.354 to 0.370 inch)
d. Using a sharp 5 mm reamer, ream the guide bushing to obtain the standard specified clearance between the guide bushing and valve stem.
Standard oil clearance: 0.030 to 0.065 mm (0.0012 to 0.0026 inch)
21. 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.
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 to 1.4 mm (0.039 to 0.055 inch).
22. REPAIR INTAKE VALVE SEAT
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 20° and 45° cutters to correct the seat.
b. If the seating is too low on the valve face, use 75° and 45° cutters to correct the seat.
c. Hand-lap the valve and valve seat with an abrasive compound.
d. Recheck the valve seating position.
23. REPAIR EXHAUST VALVE SEAT
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 20° and 45° cutters to correct the seat.
b. If the seating is too low on the valve face, use 75° and 45° cutters to correct the seat.
c. Hand-lap the valve and valve seat with an abrasive compound.
d. Recheck the valve seating position.
24. 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)
25. INSPECT VALVE LIFTER OIL CLEARANCE
a. Using a caliper gauge, measure the lifter bore diameter of the cylinder head.
Lifter bore diameter: 31.000 to 31.025 mm (1.2205 to 1.2215 inch)
b. Subtract the lifter diameter measurement from the lifter bore diameter measurement.
Standard oil clearance: 0.024 to 0.059 mm (0.0009 to 0.0023 inch)
Maximum oil clearance: 0.1 mm (0.0039 inch)
26. INSPECT CAMSHAFT
a. Inspect the camshaft for runout.
1. Place the camshaft on V-blocks.
2. Using a dial indicator, measure the circle runout at the center journal.
Maximum circle runout: 0.03 mm (0.0012 inch)
If the circle runout is greater than maximum, replace the camshaft.
b. Inspect the cam lobes.
1. Using a micrometer, measure the cam lobe height.
Standard cam lobe height: 44.617 to 44.717 mm (1.7566 to 1.7605 inch)
Minimum cam lobe height: 43.16 mm (1.6992 inch)
If the cam lobe height is less than minimum, replace the camshaft.
c. Inspect the camshaft journals.
1. Using a micrometer, measure the journal diameter.
No.1 journal diameter: 34.449 to 34.465 mm (1.3563 to 1.3569 inch)
Other journals diameter: 22.949 to 22.965 mm (0.9035 to 0.9041 inch)
If the journal diameter is not as specified, check the oil clearance.
27. INSPECT NO.2 CAMSHAFT
a. Inspect the camshaft for runout.
1. Place the camshaft on V-blocks.
2. Using a dial indicator, measure the circle runout at the center journal.
Maximum circle runout: 0.03 mm (0.0012 inch)
If the circle runout is greater than maximum, replace the camshaft.
b. Inspect the cam lobes.
1. Using a micrometer, measure the cam lobe height.
Standard cam lobe height: 44.666 to 44.766 mm (1.7585 to 1.7624 inch)
Minimum cam lobe height: 44.52 mm (1.7528 inch)
If the cam lobe height is less than minimum, replace the camshaft.
c. Inspect the camshaft journals.
1. Using a micrometer, measure the journal diameter.
No.1 journal diameter: 34.449 to 34.465 mm (1.3563 to 1.3569 inch)
Other journals diameter: 22.949 to 22.965 mm (0.9035 to 0.9041 inch)
If the journal diameter is not as specified. check the oil clearance.
28. 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 0.095 mm (0.0016 to 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 the cylinder head together.
29. INSPECT CAMSHAFT OIL CLEARANCE
a. Clean the bearing caps and the 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 13 Nm (129 kgf-cm, 9.4 ft. lbs.)
NOTICE: Do not turn the camshaft.
e. Remove the bearing caps.
f. Measure the Plastigage at its widest point.
Standard oil clearance: 0.035 to 0.072 mm (0.0014 to 0.0028 inch)
Maximum oil clearance: 0.08 mm (0.0031 inch)
If the oil clearance is greater than maximum, replace the camshaft. If necessary, replace the bearing caps and the cylinder head together.
NOTICE: Completely remove the Plastigage.
30. INSTALL CAMSHAFT BEARING CAP SETTING RING PIN
a. Using a plastic-faced hammer, tap in a new ring pin to the specified protrusion height.
Protrusion height: 8.5 to 9.5 mm (0.335 to 0.374 inch)
31. INSTALL STUD BOLT
a. Using Torx socket wrench E5 and E7, install the 7 stud bolts.
Torque:
Bolt A 10 Nm (102 kgf-cm, 7.4 ft. lbs.)
Bolt B 4.0 Nm (41 kgf-cm, 35 inch lbs.)
Bolt C 10 Nm (102 kgf-cm, 7.4 ft. lbs.)
Bolt D 9.0 Nm (92 kgf-cm, 80 inch lbs.)
32. INSTALL UNION
a. Mark the standard position away from the edge, onto the new water hose unions as shown in the illustration.
b. Apply adhesive to the water hose union hole of the cylinder head
Adhesive: Part No. 08833-00070, THREE BOND 1324 or equivalent
c. Using a press, press in a new water hose union until the marks come to the same level as the one of the cylinder head surface
Standard protrusion:
A 29 mm (1.14 inch)
B 44 mm (1.73 inch)
NOTICE:
^ Install the water hose union within 3 minutes after applying adhesive.
^ Do not expose the water house union to engine cool ant within one hour of installation.
33. INSTALL VALVE STEM OIL O-SEAL OR RING
a. Apply a light coat of engine oil on the valve stem
NOTICE: Installing the oil seal for intake and exhaust to the opposite valve guide bush may cause failures.
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
34. INSTALL INTAKE VALVE
a. Install the valve, spring seat, valve spring, and spring retainer.
NOTICE: Install the same parts in the same combination to the original locations.
b. Using SST, compress the valve spring and place the 2 retainer locks around the valve stem.
SST 09202-70020 (09202-00010)
c. Using a plastic-faced hammer and the valve stem (not in use) with the tip wrapped in tape, lightly tap the valve stem tip to ensure a proper fit.
NOTICE: Be careful not to damage the valve stem tip.
35. INSTALL EXHAUST VALVE
a. Install the valve, spring seat, valve spring, and spring retainer.
b. Using SST, compress the valve spring and place the 2 retainer locks around the valve stem.
SST 09202-70020 (09202-00010)
c. Using a plastic-faced hammer and the valve stem (not in use) with the tip wrapped in tape, lightly tap the valve stem tip to ensure a proper fit.
NOTICE: Be careful not to damage the valve stem tip.
36. INSTALL OIL CONTROL VALVE FILTER
a. Using an 8 mm hexagon wrench, place a new gasket on the plug and install the filter.
Torque: 30 Nm (306 kgf-cm, 22 ft. lbs.)
37. INSTALL VALVE LIFTER
a. Apply a light coat of engine oil on the valve lifter.
b. Install the valve lifter.
c. Check that the valve lifter rotates smoothly by hand.
38. REMOVE W/ HEAD TAPER SCREW PLUG NO.1
a. Using a 10 mm socket hexagon wrench, install the taper screw plug with a new gasket.
Torque: 44 Nm (449 kgf-cm, 33 ft. lbs.)