TM 9-2320-289-34
3-8.
VALVE REMOVAL AND REPAIR (Con’t).
NOTE
Valves (12) and seats should be
reconditioned
if
seat
width
exceeds 0.080 in. (2.03 mm),
1.
Grind valve face (15) to obtain a 45
degree angle completely around.
Measure all valve heads (1 6). If valve
head
is
less
than
(0.80 mm) thick at any point, replace
valve (12).
CAUTION
Valve
seats
are
induction
hardened. DO NOT grind valve
seats in excess of dimensions
given in step 2. Failure to follow
this caution may result in damage
to
valve
seat
and
require
replacement of cylinder head (1).
2.
Grind valve seats to obtain a 46 degree angle. Intake valve (2) seats must be 0.035-0.060 in.
(0.889-1 .52 mm) wide. Exhaust valve (3) seats must be 0.060-0.080 in. (1 .52-2 .03 mm)
wide. If any valve seat is too wide, replace cylinder head (1).
3.
Obtain valve (12) with next oversize stem. Using appropriate reaming tool for oversize valve
stem, ream valve guide (4).
FOLLOW-ON TASKS:
l Install valve. (See paragraph 3-24)
TA50639
3 - 2 7
