TM 10-4320-315-24
4-4.
MAINTENANCE OF CYLINDER HEADS - (Cont)
Figure 4-4. Cylinder Head Measurement
(6)
If measurement exceeds 0.224 in. (5.689 mm), drill out valve seats (3). Take care not to damage
cylinder head.
WARNING
Hot cylinder head can cause severe burns. Wear heat resistance gloves.
(7)
Heat cylinder head to 428°F (220°C).
(8)
Seat new valve seats in cylinder head, chamfer side of valve seats up.
(9)
Measure and record exhaust valve stem. Minimum diameter is 0.312-0.3128 in. (7.920-7.940 mm).
Replace defective valve.
(10)
Measure and record intake valve stem. Minimum diameter is 0.307-0.313 in. (7.810-7.960 mm).
Replace defective valve.
NOTE
If valves are replaced, the corresponding valve guides must also be replaced.
(11)
Measure and record the inside diameter of both valve guides.
(12)
Subtract valve stem measurements from valve guide measurements to obtain valve stem clearance.
4-7
