Cylinder Head Assembly: Testing and Inspection

1ZZ-FE ENGINE MECHANICAL: CYLINDER HEAD: INSPECTION

INSPECTION

1. INSPECT CYLINDER HEAD SET BOLT





(a) Using vernier calipers, measure the length of the cylinder head bolts from the seat to the end.
Standard length:
146.8 to 148.2 mm(5.780 to 5.835 in.)
Maximum length:
148.5 mm (5.846 in.)
If the bolt length is greater than maximum, replace the cylinder head set bolt.
2. CHECK CYLINDER HEAD FOR FLATNESS





(a) Using a precision straight edge and a feeler gauge, measure the surface that is in contact with the cylinder block and the manifolds for warpage.
Maximum warpage:
Cylinder block side
0.05 mm (0.0020 in.)
Intake manifold side
0.10 mm (0.0039 in.)
Exhaust manifold side
0.10 mm (0.0039 in.)
If the warpage is greater than maximum, replace the cylinder head.
3. CHECK 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.
4. INSPECT VALVE SEATS





(a) Apply a light coat of prussian blue to the valve face.
(b) Lightly press the valve against the seat.

NOTE: Do not turn the valve.

(c) Check the valve face and seat in accordance with 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 a width of 1.0 to 1.4 mm (0.039 to 0.055 in.).
5. REPAIR INTAKE VALVE SEATS

NOTE: Releasing the seat cutter pressure makes the valve seat faces smoother.

(a) Using a 45° cutter, cut the valve face of the cylinder head a little wider than the specified valve seating width.
(b) Confirm that the valve fits the valve seat center portion. If not, re-cut the valve face with the 45° cutter.
(c) Adjust the valve face with a 30° or 60° cutter so that the valve seat is in the valve seat center portion.





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





(2) If the seating is too low on the valve face, use the 60° and 45° cutters to correct the seat.
(d) Lap the valve and valve seat with an abrasive compound. Do this work by hand.
(e) Recheck the valve seating position.
6. REPAIR EXHAUST VALVE SEATS

NOTE: Releasing the seat-cutter pressure gradually make the valve seat faces smoother.

(a) Using the 45° cutter, cut the valve face of the cylinder head a little wider than the specified valve seating width.
(b) Confirm that the valve fits the valve seat center portion. If not, re-cut the valve face with the 45° cutter.
(c) Adjust the valve face with the 30° or 75° cutter to accurately fit the valve seat center portion.





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





(2) If the seating is too low on the valve face, use the 75° and 45° cutters to correct the seat.
(d) Lap the valve and valve seat with an abrasive compound. Do this work by hand.
(e) Recheck the valve seating position.
7. CHECK CAMSHAFT THRUST CLEARANCE





(a) Install the 2 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 in.)
Maximum thrust clearance:
0.110 mm (0.0043 in.)

- If the thrust clearance is greater than maximum, replace the cylinder head.
- If damages are found on the camshaft thrust surfaces, replace the camshaft.

8. CHECK CAMSHAFT OIL CLEARANCE





(a) Clean the 9 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 9 bearing caps (Reassembly).

NOTE: Do not turn the camshaft.

(e) Remove the 9 bearing caps (Disassembly).





(f) Measure the Plastigage at its widest point.
Standard oil clearance:
0.035 to 0.072 mm (0.0014 to 0.0028 in.)
Maximum oil clearance:
0.10 mm (0.0039 in.)

NOTE: Completely remove the Plastigage after measuring.

If the oil clearance is greater than maximum, replace the cylinder head or the camshaft.
9. INSPECT VALVE LIFTER





(a) Using a micrometer, measure the valve lifter diameter.
Lifter diameter:
30.966 to 30.976 mm (1.2191 to 1.2195 in.)
If the diameter is not as specified, replace the valve lifter.
10. CHECK VALVE LIFTER OIL CLEARANCE





(a) Using a caliper gauge, measure the valve lifter bore diameter of the cylinder head.
Lifter bore diameter:
31.000 to 31.025 mm (1.2205 to 1.2215 in.)
If the diameter is not as specified, replace the cylinder head.
(b) Subtract the valve lifter diameter measurement from the valve lifter bore diameter measurement.
Standard oil clearance:
0.024 to 0.059 mm (0.0009 to 0.0023 in.)
Maximum oil clearance:
0.079 mm (0.0031 in.)

- If the oil clearance is greater than maximum, replace the valve lifter.
- If necessary, replace the cylinder head.

11. INSPECT INNER COMPRESSION SPRING





(a) Using vernier calipers, measure the free length of the inner compression spring.
Free length:
43.40 mm (1.7087 in.)
If the length is not as specified, replace the inner compression spring.





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





(c) Using a spring tester, measure the tension of the inner compression spring at the specified installed length.
Installed tension:
158.6 to 175.4 N (16.2 to 17.9 kgf, 35.7 to 39.5 lbf) at 33.6 mm (1.323 in.)
Maximum working tension:
335.3 to 370.7 N (34.2 to 37.8 kgf, 75.4 to 83.3 lbf) at 24.1 mm (0.949 in.)
If the installed tension is not as specified, replace the inner compression spring.
12. INSPECT VALVE





(a) Using vernier calipers, measure the overall valve length.
Standard overall length:





Minimum overall length:





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:





If the diameter is not as specified, replace the valve.





(c) Using vernier calipers, check the valve head margin thickness.
Standard margin thickness:
1.0 mm (0.039 in.)
Minimum margin thickness:
0.7 mm (0.028 in.)
If the margin thickness is less than minimum, replace the valve.
13. CHECK VALVE GUIDE BUSHING OIL CLEARANCE





(a) Using a caliper gauge, measure the internal diameter of the valve guide bushing.
Bushing inside diameter:
5.510 to 5.530 mm (0.2169 to 0.2177 in.)
If the internal diameter is not as specified, replace the valve guide bushing.
(b) Subtract the valve stem diameter measurement from the guide bushing internal diameter measurement.
Standard oil clearance:





Maximum oil clearance::





If the oil clearance is greater than maximum, replace the valve and valve guide bushing.
14. REPLACE VALVE GUIDE BUSHING





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





(b) Place the cylinder head on the wooden blocks.
(c) Using SST, tap out the valve guide bushing.
SST: 09201-10000
09201-01050
SST: 09201-01055
SST: 09950-70010
09951-07100





(d) Using a caliper gauge, measure the bushing bore diameter of the cylinder head.
Diameter:
10.285 to 10.306 mm (0.4049 to 0.4058 in.)
If the bushing bore diameter of the cylinder head is greater than 10.306 mm (0.4058 in.), machine the bushing bore to a dimension of 10.335 to 10.356 mm (0.4069 to 0.4077 in.) to install an oversize valve guide bushing.









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





(f) Place the cylinder head on wooden blocks.
(g) Using SST, tap in a new valve guide bushing to the specified height.
SST: 09201-10000
09201-01050
SST: 09201-01055
SST: 09950-70010
09951-07100
Height:
8.7 to 9.1 mm (0.343 to 0.358 in.)





(h) Using a sharp 5.5 mm reamer, ream the valve guide bushing to the standard specified clearance.
Standard oil clearance: