Disassembly and Reassembly

CYLINDER HEAD

COMPONENTS (Part 1):

COMPONENTS (Part 2):

COMPONENTS (Part 3):

COMPONENTS (Part 4):

COMPONENTS (Part 5):

COMPONENTS (Part 6):

COMPONENTS (Part 7):

DISASSEMBLY

1. REMOVE VALVE LIFTER
(a) Remove the valve lifters.

HINT: Arrange the valve lifters in the correct order.

2. REMOVE INTAKE VALVE
(a) Using SST and wooden blocks, compress and remove the valve retainer locks.
SST 09202-70020 (09202-00010)
(b) Remove the retainer, valve spring and valve.

HINT: Arrange the removed parts in the correct order.

3. REMOVE EXHAUST VALVE
(a) Using SST and wooden blocks, compress and remove the valve retainer locks.
SST 09202-70020 (09202-00010)
(b) Remove the retainer, valve spring and valve.

HINT: Arrange the removed parts in the correct order.

4. REMOVE VALVE STEM OIL SEAL
(a) Using needle-nose pliers, remove the oil seals.

5. REMOVE VALVE SPRING SEAT
(a) Using compressed air and a magnetic finger, remove the valve spring seats by blowing air onto them.

6. REMOVE NO. 1 STRAIGHT SCREW PLUG
(a) Using a 14 mm straight hexagon wrench, remove the 2 screw plugs and 2 gaskets.

NOTICE: If water leaks from the straight screw plug or the plug corrodes, replace it.

7. REMOVE STUD BOLT
8. REMOVE RING PIN
9. REMOVE INTAKE VALVE GUIDE BUSH
(a) Heat the cylinder head to 80 to 100°C (176 to 212°F).
(b) Place the cylinder head on wooden blocks.

(c) Using SST and a hammer, tap out the guide bush.
SST 09201-10000 (09201-01050), 09950-70010 (09951-07100)

10. REMOVE EXHAUST VALVE GUIDE BUSH
(a) Heat the cylinder head to 80 to 100°C (176 to 212°F).
(b) Place the cylinder head on wooden blocks.

(c) Using SST and a hammer, tap out the guide bush.
SST 09201-10000 (09201-01050), 09950-70010 (09951-07100)

INSPECTION

1. 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:

If the warpage is greater than the maximum, replace the cylinder head.

2. INSPECT CYLINDER HEAD FOR CRACKS
(a) Using a dye penetrant, check the intake ports, exhaust ports and cylinder surface for cracks. If cracked, replace the cylinder head.

3. INSPECT VALVE SEATS
(a) Apply a light coat of Prussian blue to the valve face.
(b) Lightly press the valve face against the valve seat.
(c) Check the valve face and valve seat according to the following procedure:
(1) If Prussian blue appears 360° around the valve face, the valve face is concentric. If not, replace the valve.
(2) If Prussian blue appears 360° around the valve seat, the guide and valve face are concentric. If not, resurface the valve seat.
(3) Check that the valve seat contact is in the middle of the valve face with the valve seat width between 1.0 and 1.4 mm (Intake side (0.039 to 0.055 inch)).
(4) Check that the valve seat contact is in the middle of the valve face with the valve seat width between 1.2 and 1.6 mm (Exhaust side (0.047 to 0.063 inch)).

4. REPAIR VALVE SEATS

NOTICE:
^ Repair the seat while checking the seating position.
^ Keep the lip free from foreign matter.

(a) Using a 45° cutter, resurface the valve seat so that the valve seat width is more than the specification.

(b) Using 30° and 75° cutters, correct the valve seat so that the valve contacts the entire circumference of the seat. The contact should be in the center of the valve seat, and the valve seat width should be maintained within the specified range around the entire circumference of the seat.

Valve seat width:

(c) Hand rub the valve and valve seat with an abrasive compound.
(d) Check the valve seating position.

5. 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:

Maximum thrust clearance:

If the thrust clearance is greater than the maximum, replace the cylinder head. If the thrust surface is damaged, replace the camshaft.

6. INSPECT CAMSHAFT OIL 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 journals.
(d) Install the bearing caps.

NOTICE: Do not turn the camshaft.

(e) Remove the bearing caps.

(f) Measure the Plastigage at its widest point.

Standard oil clearance:

Maximum oil clearance:

NOTICE: Completely remove the Plastigage after the inspection.
^ If the oil clearance is greater than the maximum, replace the camshaft. If necessary, replace the cylinder head.
^ If the oil clearance on the camshaft No. 1 journal is greater than the maximum, choose a new bearing and install it.

(1) Check the number mark shown in the illustration.
Cylinder head journal bore diameter

Standard bearing center wall thickness:

Camshaft journal diameter:

7. INSPECT INNER COMPRESSION SPRING
(a) Using vernier calipers, measure the free length of the valve spring.
Free length: 47.43 mm (1.867 inch)
If the free length is not as specified, replace the valve spring.

(b) Using steel squares, measure the deviation of the valve spring.
Maximum deviation: 1.6 mm (0.063 inch)
If the deviation is greater than the maximum, replace the valve spring.

8. INSPECT INTAKE VALVE
(a) Using a gasket scraper, scrape off any carbon on the valve head.

(b) Using vernier calipers, measure the overall length of the valve.
Standard overall length: 101.71 mm (4.0043 inch)
Minimum overall length: 101.21 mm (3.9846 inch)
If the overall length is less than the minimum, replace the valve.

(c) 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)
If the valve stem diameter is not as specified, check the oil clearance.

(d) Using vernier calipers, measure the valve head margin thickness.
Standard margin thickness: 1.05 to 1.45 mm (0.0413 to 0.0571 inch)
Minimum margin thickness: 0.50 mm (0.0197 inch)
If the margin thickness is less than the minimum, replace the valve.

9. INSPECT EXHAUST VALVE
(a) Using a gasket scraper, scrape off any carbon on the valve head.

(b) Using vernier calipers, measure the overall length of the valve.
Standard overall length: 101.15 mm (3.9823 inch)
Minimum overall length: 100.70 mm (3.9646 inch)
If the overall length is less than the minimum, replace the valve.

(c) 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)
If the valve stem diameter is not as specified, check the oil clearance.

(d) Using vernier calipers, measure the valve head margin thickness.
Standard margin thickness: 1.20 to 1.60 mm (0.0472 to 0.0630 inch)
Minimum margin thickness: 0.50 mm (0.0197 inch)
If the margin thickness is less than the minimum, replace the valve.

10. INSPECT INTAKE VALVE GUIDE BUSH
(a) Using a caliper gauge, measure the inside diameter of the guide bush.
Bushing inside diameter: 5.510 to 5.530 mm (0.2169 to 0.2177 inch)
(b) Subtract the valve stem diameter measurement from the guide bush inside diameter measurement.
Standard oil clearance: 0.025 to 0.060 mm (0.0010 to 0.0024 inch)
Maximum oil clearance: 0.080 mm (0.0031 inch)
If the clearance is greater than the maximum, replace the valve and guide bush.

11. INSPECT EXHAUST VALVE GUIDE BUSH
(a) Using a caliper gauge, measure the inside diameter of the guide bush.
Bushing inside diameter: 5.510 to 5.530 mm (0.2169 to 0.2177 inch)
(b) Subtract the valve stem diameter measurement from the guide bushing inside diameter measurement.
Standard oil clearance: 0.030 to 0.065 mm (0.0012 to 0.0026 inch)
Maximum oil clearance: 0.100 mm (0.0039 inch)
If the clearance is greater than the maximum, replace the valve and guide bush.

12. 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)

(b) Using a caliper gauge, measure the lifter bore diameter of the cylinder head.
Standard lifter bore diameter: 31.009 to 31.025 mm (1.2208 to 1.2215 inch)
(c) 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: 0.070 mm (0.0028 inch)
If the oil clearance is greater than the maximum, replace the lifter. If necessary, replace the cylinder head.

13. INSPECT CYLINDER HEAD SET BOLT
(a) Using vernier calipers, measure the length of the cylinder head set bolt from the seat to the end.
Standard bolt length: 141.3 to 142.7 mm (5.563 to 5.618 inch)
Maximum bolt length: 144.2 mm (5.677 inch)
If the bolt length is greater than the maximum, replace the cylinder head set bolt.

REASSEMBLY

1. INSTALL INTAKE VALVE GUIDE BUSH
(a) Using a caliper gauge, measure the bush bore diameter of the cylinder head.

If the bush bore diameter of the cylinder head is greater than 10.306 mm (0.4057 inch), machine the bush bore to the dimension of 10.335 to 10.356 mm (0.4069 to 0.4077 inch) to install an O/S 0.05 valve guide bush. If the bush bore diameter of the cylinder head is greater than 10.356 mm (0.4077 inch), replace the cylinder head.
(b) Heat the cylinder head to 80 to 100°C (176 to 212°F).
(c) Place the cylinder head on wooden blocks.

(d) Using SST and a hammer, tap in a new guide bush to the specified protrusion height.
SST 09201-10000 (09201-01050), 09950-70010 (09951-07100)
Protrusion height: 9.6 to 10.0 mm (0.3779 to 0.3937 inch)

(e) Using a sharp 5.5 mm reamer, ream the guide bush to obtain the standard specified clearance between the guide bush and valve stem.
Standard oil clearance: 0.025 to 0.060 mm (0.0010 to 0.0024 inch)

2. INSTALL EXHAUST VALVE GUIDE BUSH
(a) Using a caliper gauge, measure the bush bore diameter of the cylinder head.

(e) Using a sharp 5.5 mm reamer, ream the guide bush to obtain the standard specified clearance between the guide bush and valve stem.
Standard oil clearance: 0.030 to 0.065 mm (0.0012 to 0.0026 inch)

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

4. INSTALL STUD BOLT

NOTICE: If the stud bolt is deformed or the threads are damaged, replace it.

(a) Using E5 and E7 "TORX" sockets, install the stud bolts.

5. INSTALL NO. 1 STRAIGHT SCREW PLUG
(a) Using a 14 mm straight hexagon wrench, install 2 new gaskets and the 2 straight screw plugs.

6. INSTALL VALVE SPRING SEAT
(a) Install the valve spring seats to the cylinder head.

7. INSTALL VALVE STEM OIL SEAL
(a) Apply a light coat of engine oil to 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 side or installing the exhaust oil seal to the intake side can cause installation problems later.

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

(b) Using SST, push in the oil seal.
SST 09201-41020

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

8. INSTALL INTAKE VALVE
(a) Sufficiently apply engine oil to the tip area of the intake valve shown in the illustration.
(b) Install the valve, compression spring and spring retainer to the cylinder head.

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

(d) Using a 5 mm pin punch and plastic hammer, lightly tap the valve stem tip to ensure a proper fit.

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

9. INSTALL EXHAUST VALVE
(a) Sufficient apply engine oil to the tip area of the exhaust valve shown in the illustration.
(b) Install the valve, compression spring and spring retainer to the cylinder head.

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

(d) Using a 5 mm pin punch and plastic hammer, lightly tap the valve stem tip to ensure a proper fit.

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

10. INSTALL VALVE LIFTER
(a) Apply a light coat of engine oil to the tip of each valve stem.
(b) Install the valve lifters.

NOTICE: Install the valve lifters in their original places.