TM 10-4320-226-14
6.6.2
h.
i.
j.
k.
Cylinder Head Repair. (continued)
Check clearance of valve stems in guides of both valves.
If it exceeds .0016
inch (.04 mm) inlet valve, or .0024 (.06 mm) exhaust valve, replace guides.
Mandrels (intake and exhaust) come in two sizes.
One will
fit exhaust valve seat and other will fit intake valve
seat.
Remove valve seat as follows:
(1)
(2)
(3)
(4)
(5)
(6)
Heat
head
Place mandrel (figure 6-5, 1) on valve seat and insert guide through
mandrel into valve stem.
Tighten guide so that mandrel is firmly in
place.
Do not drill into cylinder head.
Failure to obey this
caution may result in equipment damage.
Insert drill (2) into mandrel (1) and drill through valve seat at two
positions 180° apart.
Remove guide and
Carefully remove
Measure diameter
mandrel (1).
drilled seat.
of valve seat bore in cylinder head.
Intake valve seats have larger outside diameter than
exhaust valve seats.
Measure outside diameter of new valve seat.
Subtract the diameter of
bore from diameter of seat.
Difference must not be less than
0.003 inch (0.076 m).
Heating cylinder head for more than
higher tempreture than 430° F (220°
head to warp.
Failure to obey this
Remove
equipment damage.
cylinder head in oven to a
more that 30 minutes.
30 minutes or at a
C) may cause cylinder
caution could result in
temperature of 430° F (220° C).
Do not heat
Do not touch cylinder head while it is hot without
protective gloves.
Exercise care when working around hot
cylinder head.
Severe burns can result if protective
measures are not taken.
Failure to obey this warning may
result in personal injury.
head from oven.
6-15
