Inspection

1. CLEAN TOP OF PISTONS AND TOP OF CYLINDER BLOCK

(a) Turn the crankshaft and bring each piston to top dead center (TDC)
(b) Using a gasket scraper, remove all gasket material from the top of the block. Blow carbon and oil from the bolt holes.
(c) Using compressed air, blow carbon and oil from the bolt holes.

CAUTION: Protect your eyes when using high pressure air.

2. REMOVE GASKET MATERIAL
Using a gasket scraper, remove all gasket material from the cylinder head and manifold surfaces.

NOTICE: Be careful not to scratch the surfaces.

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

NOTICE: Be careful not to scratch the head gasket contact surface.

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

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

6. INSPECT CYLINDER HEAD FOR FLATNESS
Using a precision straight edge and thickness gauge, measure the surface contacting the cylinder block and manifold for warpage.
Maximum warpage: 0.1Omm (0 .00391n.)
If warpage is greater than maximum, replace the cylinder head.
7. INSPECT CYLINDER HEAD FOR CRACKS

Using a dye penetrant, check the combustion chamber, intake and exhaust ports, head surface and the top of the head for cracks. If cracked, replace the cylinder head.
8. CLEAN VALVES

(a) Using a gasket scraper, chip any carbon from the valve head.
(b) Using a wire brush, thoroughly clean the valve.
9. INSPECT VALVE STEMS AND VALVE GUIDE BUSHINGS

(a) Using a caliper gauge, measure the inside diameter of the valve guide bushing.
Valve guide bushing inside diameter: 6.010 - 6.030 mm (0.2366 - 0.2374 in.)

(b) Using a micrometer, measure the diameter of the valve stem.
Valve stem diameter:
Intake 5.970 - 5.985 mm (0.2350 - 0.2356 in.)
Exhaust 5.965 - 5.980 mm (0.2348 - 0.2354 in.)
(c) Subtract the valve stem diameter measurement from the valve guide bushing measurement.
Standard stem oil clearance:
Intake 0.025 - 0.060 mm (0.0010 - 0.0024 in.)
Exhaust 0.030 - 0.065 mm (0.0012 - 0.0036 in.)
Maximum stem oil clearance:
Intake 0.08 mm (0.0031 in.) Exhaust 0.10 mm (0.0039 in.)
If the clearance is greater than maximum, replace the valve and guide bushing.
10. IF NECESSARY, REPLACE VALVE GUIDE BUSHINGS

(a) Insert an old valve wrapped with tape into the valve
guide bushing and break off the valve guide bushing by hitting it with a hammer.

NOTICE: Be careful not to damage the lifter hole.

(b) Gradually heat the cylinder head to approx. 90°C (194°F).

(d) Using a caliper gauge, measure the valve guide bushing bore of the cylinder head.

(e) Select a new valve guide bushing.
If the valve guide bushing bore of the cylinder head is more than 11.027 mm (0.4341 in.), machine the bore to the following dimension:
Rebored cylinder head bushing bore dimension:
11.050 - 11.077 mm (0.4350 - 0.4361 in.)
If the bushing bore diameter of the cylinder head is greater than 11.077 mm (0.4361 in.), replace cylinder head.
(f) Gradually heat the cylinder head to approx. 90°C (194°F)
.

(g) Using SST and hammer, tap in a new valve guide bushing until the snap ring makes contact with the cylinder head. SST 09201-70010
(h) Using a sharp 6 mm (0.23 in.) reamer, ream the valve guide bushing to obtain standard specified clearance between the valve guide bushing and new valve stem.

11. INSPECT AND GRIND VALVES
(a) Grind the valve only to enough remove pits and carbon.
(b) Check that the valve is ground to the correct valve face angle.
Valve face angle: 44.5°

(c) Check the valve head margin thickness.
Standard margin thickness: 1.3 mm (0.051 in.)
Minimum margin thickness: 0.5 mm (0.020 in.)
If the valve head margin thickness is less than minimum replace the valve.

(d) Check the valve overall length.
Standard overall length: 98.15 mm (3.8642 in.)
Minimum overall length: 97.75 mm (3.8484 in.)
If the valve 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, resurface it with grinder or replace the valve.

NOTICE: Do not grind off more than minimum overall length.

12. 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 thin coat of prussian blue (or white lead) to the valve face. Install the valve. Lightly press the valve against the seat. Do not rotate the 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 seat are concentric. If not, resurface the seat.
- Check that the seat contact is on the middle of the valve face with the following width: 1.0 1.4 mm (0.039 - 0.055 in.)
If not, correct the valve seat as follows:

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

- If seating is too low on the valve face, use 60° 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.
13. INSPECT VALVE SPRINGS

(a) Using a steel square, measure the squareness of the valve springs.
Maximum squareness: 1.5 mm (0.059 in.)
If squareness is greater than maximum, replace the valve spring.

(b) Using calipers, measure the free length of the valve spring.
Free length:41.64 mm (1.6394 in.)
If the free length is not within specification, replace the valve spring.

(c) Using a spring tester, measure the tension of the valve spring at the specified installed length.
Installed tension: 16.0kg (35 lb, 157 N) at 35.0 mm (1.378 in.)
If the installed tension is not as specified, replace the valve spring.
14. INSPECT CAMSHAFT AND BEARINGS
A. 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 in.)
If the circle runout is greater than maximum, replace the camshaft.

B. Inspect cam lobes
Using a micrometer, measure the cam lobe height.
Standard cam lobe height:
Intake38.16 mm (1.5024 in.) Exhaust 38.35 mm (1.5098 In.)
Minimum cam lobe height:
Intake 37.85 mm (1.4902 in.)
Exhaust 38.00 mm (1.4961 in.)
If the cam lobe height is less than minimum, replace the camshaft.
C. Inspect camshaft journals

Using a micrometer, measure the journal diameter.
Journal diameter:
No.1 journal 26.949 - 26.965 mm (1.0610 - 1.0616 in.)
No.2 - No.7 journals 26.888 - 26.975 mm (1.0586 - 1.0620 in.)
If the journal diameter is not as specified, check the oil clearance.
D. Inspect camshaft journal oil clearance
(a) Clean the bearing caps and camshaft journals.
(b) Place the camshaft in the cylinder head.

(d) Place the bearing caps on each journal with the front marks pointing toward the front and in numerical order from the front side.

(e) Install and uniformly tighten the cap bolts in several passes, in the sequence shown.
Torque: 200 kg-cm (14 ft-lb, 20 N.m)

HINT: Do not turn the camshaft.

(f) Remove the bearing caps.

(g) Measure the Plastigage at its widest point.
Standard oil clearance:
No.1 journal 0.035 - 0.072 mm (0.0014 - 0.0028 in.)
No.2 - No.7 journals 0.025 - 0.093 mm (0.0010 - 0.0037 in.)
Maximum oil clearance: 0.13 mm (0.0051 in.)
If oil clearance is greater than maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
(h) Completely remove the Plastigage.
E. Inspect camshaft thrust clearance
(a) Clean and install the camshaft and bearing caps.

(b) Using a dial gauge, measure the thrust clearance while moving the camshaft back and forth.
Standard thrust clearance: 0.08-0.19 mm (0.0031 - 0.0075 in.)
Maximum thrust clearance: 0.30 mm (0.0118 in.)
If the thrust clearance is greater than maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
15. INSPECT VALVE LIFTER AND LIFTER BORE

(a) Using a micrometer, measure the diameter of the valve lifter.
Valve litter diameter: 27.975 - 27.985 mm (1.1014 - 1.1018 in.)

(b) Using a dial indicator, measure the lifter bore diameter of the cylinder head.
Lifter bore diameter: 28.000 - 28.021 mm (1.1024 - 1.1032 in.)
(c) Subtract the valve lifter diameter measurement from the lifter bore diameter.
Standard oil clearance: 0.015 - 0.046 mm (0.0006 - 0.0018 in.)
Maximum oil clearance: 0.10 mm (0.0039 in.)
If the oil clearance is greater than maximum, replace the valve lifter. If necessary, replace the cylinder head.
16. INSPECT INTAKE, EXHAUST MANIFOLDS AND AIR INTAKE CHAMBER

Using a precision straight edge and feeler gauge, check the surfaces contacting the cylinder head or intake manifold for warpage.
Maximum warpage:
Intake manifold 0.10 mm (0.0039 in.)
Exhaust manifold 0.75 mm (0.0295 in.)
Air intake chamber 0.10 mm (0.0039 in.)
If warpage is greater than maximum, replace the manifold.