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8-50
FIG. 13-
Removing Valve
Stem Burrs
6518
6514
LOCKS~~~
RETAINER
SPR~NG
_.
D7ER
6571
~ ~
OILSEAL
' I
-
SJ.
~651
3
EXHAUST
VALVE
65()1;
~
INTAKE
VALVE
1.1\07
A3243-A
FIG. 14- Valve and Related Parts
FIG.
15-
Valve Spring Assembled Height
1.
Clean the spring
retainer lock
grooves on
the
valves
to
remove any
loose
rna terial
left by the valve stem
de-burring
tool.
2.
Lubricate the valve guide and
valve
stem with
heavy
engine
oil MS.
3.
Install
each valve (Fig. 14)
in the
port
from which it was
removed or to
which
it was fitted. Install a
new stem
seal
on the
valve.
GROUP 8-
ENGINE
4.
Install the valve spring over the
valve, and then install the spring retainer.
Compress
the spring and install the
retainer locks (Fig. 12).
5.
Measure the assembled height of
the valve spring from the surface of the
cy
Iinder head spring pad to the underside
of the
spring
retainer with dividers (Fig.
15). Check the dividers against a scale. If
the assembled height is greater than
specifications,
install
the
necessary
0.030-inch thick spacer(s) between the
cylinder head
spring
pad and the valve
spring
to bring the assembled height to the
recommended
height.
Do
not install the spacers unless
necessary. Use of spacers in excess of
recommendations
will
result
in
overstressing
the
valve
springs
and
overloading the camshaft lobes which
could lead to spring breakage and/or worn
camshaft lobes.
6.
Install the
exhaust
manifolds and
the
spark
plugs.
VALVE SPRING, RETAINER AND
STEM SEAL
Broken valve springs or damaged valve
stem
seals
and retainers may be replaced
without removing
the cylinder head,
provided damage to the valve or valve seat
has not occurred.
REMOVAL
1.
Disconnect the automatic choke
heat chamber
air
inlet hose from the inlet
tube near the right
valve
rocker arm cover.
2.
Remove the
air
cleaner and intake
duct
assembly.
To remove the right valve rocker arm
cover, remove the crankcase ventilation
regulator valve from the valve rocker arm
cover.
3.
Remove the valve rocker arm
cover
and the applicable spark plug.
FIG. 16- Compressing Valve Spring in
Chassis
4.
Remove the
valve rocker arm
fulcrum, bolts, fulcrum
seats,
valve
rocker
arms
and
push rods
from the applicable
cylinder.
5.
Install
an
air line
with
an
adapter
in the
spark
plug hole and
turn
on
the air
supply.
6.
Install the
compressor
tool
as
shown in
Fig. 16. Compress
the
valve
spring and remove
the retainer
locks,
spring
retainer
and
valve
spring.
7.
Remove
and
discard the
valve
stem seal (Fig. 17).
8.
If
air pressure has forced the
piston to the bottom of the
cylinder, any
removal of air pressure will
allow
the
valve(s) to fall into
the cylinder.
A rubber
band, tape or
string
wrapped around the
end of the valve
stem will
prevent this
condition and will
still
allow enough travel
to check the valve for binds.
FIG. 17- Removing or Installing Valve
Stem Seal
FIG. 18- Removing Crankshaft Vibration
Damper
INSTALLATION
1.
Inspect
the
valve
stem
for
damage. Rotate the valve
and check the
valve
stem
tip for
eccentric
movement
during
rotation.
Move
the valve
up
and
down through normal travel in
the valve
guide
and check
the
stem for
binds.
If the
valve has been damaged, it will be
necessary to remove the
cylinder
head for
repairs.
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