Toyota 4-Runner 1985 Repair Manual page 50

ENGINE MECHANICAL - Cylinder Head EM-21
(f) Using a sharp 8 mm reamer, ream the valve guide to
obtain the specified clearance between the guide and
new valve.
Intake clearance: 0.02 - 0.06 mm (0.0008 - 0.0024 in.)
Exhaust clearance: 0.03 - 0.07 mm (0.0012 - 0.0028 in.)
11. INSPECT AND GRIND VALVES
(a) Grind the 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 0
(b) Check the valve head margin.
If the valve head margin is less than specified, replace the
valve.
Minimum margin: 0.6 mm (0.024 in.)
(c) Check the surface of the valve stem tip for wear.
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.)
Standard overall length:
Intake 113.5 mm (4.468 in.)
Exhaust 112.4 mm (4.425 in.)
12. INSPECT AND CLEAN VALVE SEATS
(a) Using a 45 0 carbide cutter, resurface the valve seats.
Remove 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, rorate the valve against the seat.
(c) Check the valve face and seat for the following:
• If blue appears 360 0 around the face, the valve is
concentric. If not, replace the valve.
• If blue appears 360
0
around the valve seat, the
guide and seat are concentric. If not, resurface the
seat.