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1-8
GROUP 1- ENGINES
FIG.
l-Exhau
st
Gas
Control Val ve-223
Six
FIG.
3-Pu sh Rod Runout-Typical
Inspect
the manifolds
fo
r
cracks,
leaks,
or other
defects
that
would
make
the
m
unfit
for
fu
rt
her
service.
Replace
a
ll
studs
that are
stripped
or
otherwise damaged.
Re move a
ll
fil-
ings and roreign
mailer
that may have
entered
the
manifolds
as
a
result
of
repairs.
EXHAUST GAS CONTROL
VALVE-223
SIX
AND 292
MD V-8
C heck the thermostatic
spring to
make
SUfe
it
is hooked
on the
slOp
pin.
The spring stop
is
at
the lOp
of
the
valve
housing
when
the
va lve is
properly
installed. The
action of
the
valve
is illustrated
in Fig.
I or 2.
Check
to
make
SUfe
the
spring
holds the valve
closed when
the
cn-
gine
is
cold.
Actuate the
counter-
weight by
hand
to make
sure
it
moves
freely through approximately
90°
of
rotation without
binding.
The valve is
closed when the
engine
is
at
normal operating
temper.
ature
and running at idle speed.
How-
ever,
a properly
operating valve
will
open
when
very
light
finger
pressure
is applied
to the
counterweight.
Rap-
idly accelerate
the
engine
to
make
sure
the
valve
momentarily
opens.
The
valve
is designed
to
open
when
the engine is
at
normal
operating
FIG.
2-Exhau s.
Gas Control
Val
ve-
292
MD V-8
FIG.
4-Cylinder
He
ad Flatne
ss-Typical
temperature
and
is
operated
at
high
rpm.
Free slUck
valves
with a pene-
trating
oil
and
graphite mixture.
VALVE
ROCKER ARM
SHAFT ASSEMBLY
Clean
all
the parts thoroughly.
Make
sure
that
all
oil
passages are
open.
Check
the clearance
between
each
roc ker ar
m and
the
shaft
by
checking
the
J.D.
of
the
rocker
arm
bore and
the
0.0. o
f
the shaft. If the clearance
between
any rocker
arm
and the
shaft
exceeds the
wear
limit,
replace the
shaft
and/or
the rocker arm. Inspect
the
shaft
and the rocker
arm
bore
for
nicks, scratches.
scores,
or
scuffs.
Dress
up
minor
surface
defects
with
a hone.
Inspect
the
pad
at the
valve
end of
the
rocker
arms
for
a
grooved
radius.
If
the
pad
is
grooved,
replace
Ihe
rocker
arm
.
Do not
attempt
to
true
this
surface
by
grinding.
Check
the
rocker
arm adjusting
screws
and
the push rod
end
of the
rocke
r
arms for stripped
or
broken
threads, and
the
ball
end
of
the
adjusting
screw for nicks, scratches,
or
excessive
wear.
C heck
for broken locating
springs.
Inspect the
oil
tu
bes
(except
SO V-8
engines)
for
cracks
or sharp
bends.
PUSH RODS
Check
the ball end
and the socket
end
o
f the
push
rods
for nicks,
grooves,
roughness,
or
excessive
wear.
The
push
rods
can be
visually
checked
for straightness while they
are
installed in
the
engine by
rotating
them
with the
valve
closed. They
also can
be
checked between ball
and
cup
centers
with a
dial indicator (Fig.
3
)
.
I
f
the runout
exceeds
the
maxi-
mum limit at any
point,
discard
the
rod.
Do
not
attempt
to
straighten
push
rods.
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