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ENGlNES-4-CYLINDER
9-1 1
(a). Install sleeve Tool C-3973 over the valve stem
and install valve (Fig. 1 2 ) . The special sleeve places the
valve at the correct height for measuring with a dial
indicator.
(b). Attach the dial indicator Tool C-3339 to
the cyl-
inder head and set it at right angle to the valve stem
being measured (Fig. 1 3 ) .
(c). Move the valve to and from
the indicator. The
total dial indicator reading should not exceed .016 inch
on intake valves and .018 inch on exhaust valves. Ream
the guides for valves with oversize stems
if the dial
indicator reading is excessive
or
if the stems are
scuffed
or
scored.
Service valves
are
available in standard, .005, .015
and .030 inch oversizes. Reamer to accommodate the
oversize valve stem
are as
follows: Reamer Tool
C-
3433 (.005"
O.S.),
Reamer Tool C-3430 (.015"
O.S.),
Reamer Tool C-3427 (.030"
O . S . ) .
(d).
Slowly turn reamer by hand and clean guide
thoroughly before installing a new valve.
Do
not at-
tempt to ream the valve guides from standard direct-
ly to
.030
inch. Use step procedure of
.005, .015
and
.030
inch so the valve guides may
be
reamed true in
relation to the valve seat.
REFACING VALVES AND VALVE SEATS
(1) The intake and exhaust valve seats and the in-
take valve face have a 45 degree angle. The exhaust
valve face has a 43 degree angle. The valve face and
valve seatangles, are shown in Figure 14.
(2) Inspect the remaining margin after the valves
are refaced (Fig. 1 5 ) . Valves with less than
3/e4
inch
margin should be replaced.
(3) When refacing the valve seats, it is important
that the correct size valve guide pilot be used for
re-
seating stones. A true and complete surface must be
obtained.
(4) Measure the concentricity of the valve seat us-
ing dial indicator No. 13725. The total runout should
not exceed .002 inch (total indicator reading).
(5) Inspect the valve seat with Prussian blue to
determine where the valve contacts the seat. To do
this, coat the valve seat
lightly
with Prussian Blue
then set the valve in place. Rotate the valve with light
pressure. If the blue
is
transferred to the center of
the valve face, the contact
is satisfactory. If the blue
is transferred to the top edge of the valve face, lower
the valve seat with
a
30" stone. If the blue is trans-
ferred to the bottom edge of the valve face raise the
valve seat with
a
60"
stone.
(6) When the seat is properly positioned the width
of the intake
seats
should be
5/e4
to
3/92
inch. The
width
of the exhaust seats should be
3/er
to
'Ile
inch.
EXHAUST:
3/64
T O
1/16
INCH)
B
-
FACE ANGLE (INTAKE:
45"-
EXHAUST:
43')
I - -
<FAT
ANGLE
(INTAKE: 45'-
EXHAUST: 45')
-
~ - . . . . . - - - I
- V A I V F
FACF
PI
I
Fig. Irl-Valve Face and Seat Angle
TESTING VALVE SPRINGS
(1) Whenever the valves have been removed
for in-
spection, reconditioning
or
replacement, the valve
springs should be tested. To test a spring, determine
the length at which the spring is to be tested.
As
an
example, the compressed length of the spring to be
tested is 15/1e inches. Turn the table of Tool C-647 un-
til the surface is in line with the 1511e inch mark on the
threaded stud and the zero mark to the front. Place
the spring over the stud on table and lift the com-
pressing lever to set the tone device. Pull on torque
wrench until ping is heard. Take
the
reading on
torque wrench at this instant. Multiply this reading
by two. This will give the spring load at the
test
length. Fractional measurements are indicated on the
table for finer adjustments. The valve springs should
INTAKE
-T
VALVE
VALVE SPRING RETAINER
LOCK GROOVES
7
EXHAUST
VALVE
KH330C
Fig. I L n t a k e and Exhaust Valves
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