1. CLEAN TOP OF PISTONS AND TOP OF BLOCK
(a) Turn the crankshaft and bring each piston to top dead center. Scrape the carbon from the piston top.
(b) Remove all gasket material from the top of the block. Blow carbon and oil from the bolt holes.
2. CLEAN COMBUSTION CHAMBERS
Using a wire brush, remove all the carbon from the combustion chambers.
CAUTION: Be careful not to scratch the head gasket contact surface.
3. CLEAN VALVE GUIDES
Using a valve guide brush and solvent, clean all the valve guides.
4. REMOVE GASKET MATERIAL
Using a gasket scraper, remove all gasket materials from the manifold and head surface.
CAUTION: Do not scratch the surface.
5. CLEAN CYLINDER HEAD
Using a soft brush and solvent, clean the head.
CAUTION: Do not clean the head In a hot tank as this will seriously damage it.
6. CHECK HEAD FOR FLATNESS
(a) Using a precision straight edge and feeler gauge, check that neither the head nor manifold surface is warped.
(b) Measure warpage at the four sides and diagonally as illustrated. Maximum head surface warpage:
0.10 mm (0.0039 in.) Maximum intake manifold surface warpage:
0.10 mm (0.0039 in.) Maximum exhaust manifold surface warpage:
0.10 mm (0.0039 in.) Maximum camshaft housing surface warpage:
If warpage is greater than specified value, replace the 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 a crack is found, replace the head.
8. CLEAN VALVES
Use a gasket scraper to chip any carbon from the valve head.
Using a wire brush, clean the valve thoroughly.
9. INSPECT VALVE STEM GUIDE WEAR
(a) Using a dial indicator or telescoping gauge, measure the inside diameter of the valve guide.
Standard inside diameter: 8.01 — 8.03 mm
(b) Using a micrometer, measure the diameter of the valve stem.
Standard valve stem diameter:
(c) Subtract the valve stem measurement from the valve guide measurement.
Standard oil clearance:
Maximum oil clearance:
Intake 0.08 mm (0.0031 in.) Exhaust 0.10 mm (0.0039 in.)
If the clearance is greater than following values, replace the valve and guide:
10. IF NECESSARY. REPLACE VALVE GUIDE
(a) 8rake the valve guide using a brass bar and hammer.
(b) Heat the cylinder head to approx. 90°C (194°F).
(c) Using SST and a hammer, drive out the valve guide. SST 09201-60011
Guide bore mm (in.)
13.000 13.027 (0.5118-0.5129)
Over 13.027 (0.5129)
Use 0/S 0.05
(d) Using a caliper gauae, measure the valve guide bore of the cylinder head.
(e) Select a new valve guide.
If the valve guide bore of the cylinder head is more than 13.027 mm (0.51 29 in.), machine the bore to the following dimensions.
Rebored valve guide bushing bore dimension (cold): 13.05-13.077 mm (0.5138-0.5148 In.)
(f) Heat the cylinder head to about 90°C (194°F).
(g) Using SST and a hammer, drive in the new valve guide until the snap ring makes contact with the cylinder head.
(h) Using a sharp 8-mm reamer, ream the valve guide to obtain specified clearance between the guide and new valve.
Standard oil clearance:
11. INSPECT AND GRIND VALVES
(a) Grind valves only enough to remove pits and carbon. Make sure the valves are ground at the correct valve face angle.
Valve face angle: 44.5°
(b) Check the valve head margin.
Minimum margin: Intake 0.5 mm (0.020 in.)
If the valve head margin is less than specified, replace the valve.
(c) Check the surface of the valve stem tip for wear.
Standard overall length:
Intake 107.5 mm (4.232 In.) Exhaust 109.7 mm (4.319 In.)
If the valve stem tip is worn, resurface the tip with a grinder or replace the valve.
CAUTION: Do not grind more than 0.5 mm (0.020 in.).
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. While applying light pressure to the valve, rotate the valve against the seat.
(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:
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° (IN) or 67.5° (EX) and 45° cutters to correct the seat.
(d) Hand-lap the valve and valve seat together with abrasive compound.
(e) Clean the valve and valve seat after hand-lapping.
13. INSPECT VALVE SPRINGS
<a) Using a steel square, check the squareness of the valve springs.
Maximum allowable: 2.0 mm (0.079 in.)
If squareness is greater than maximum, replace the valve spring.
(b) Measure the free height of all springs.
Intake side 49.1 mm (1.933 in.) Exhaust side 52.5 mm (2.067 in.) Replace any spring that is not correct.
(c) Using a spring tester, check the tension of each spring at the specified installed height.
Intake side 40.0 mm (1.576 in.) Exhaust side 43.0 mm (1.693 in.)
(76.5 - 84.4 lb, 340 - 376 N) Exhaust side 33.3 - 36.7 kg
If not within the installed tension specification, replace the spring.
14. INSPECT INTAKE, EXHAUST MANIFOLDS AND AIR INTAKE CHAMBER
Using a precision straight edge and feeler gauge, check the surfaces contacting the cylinder head for warpage.
Maximum intake war page: 0.1 mm (0.004 In.) Maximum exhaust warpage: 0.75 mm (0.0295 in.) Maximum air intake chamber warpage: 0.1 mm
If warpage is greater than maximum, replace the manifold or air intake chamber.
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