Ford Thunderbird 1957 - Rocker Arm Assembly; Push Rods; Cylinder Head; Cylinder Head Flatness

Section
3
Manifolds
and
Exhaust
Gas
Control
Valve
1-11
hooked
on
the
stop
pin.
The
spring
stop
is
at the
top
of
the
valve
housing
when
the
valve
is
properly
installed.
The
action
of
the
valves is
illustrated in
Figs. 1
and
2.
Check
to
make
sure
the
spring
holds the
valve closed
when
the
engine
is
cold.
Actuate
the
counterweight
by
hand
to
make
sure
it
moves
freely
through
approximate
ly
90
of
rotation
without
binding.
The
valve
is
closed
when
the
engine
is at normal
operating
temperature
and
running
at
idle
speed.
How
ever,
a
properly
operating
valve
will
open
when
very
light
finger
pressure is
applied
to
the
counterweight.
Rapidly
accelerate the
engine to
make
sure
the
valve
momentarily
opens.
The
valve
is
designed
to
open
when
the engine is
at
normal
operating
temperature
and
is
operated
at
high
rpm.
Free
stuck
valves
with
a
pene
trating
oil
or
graphite
mixture.
4.
ROCKER
ARM
ASSEMBLY,
PUSH
RODS,
AND
CYLINDER
HEADS
Rocker
Arm
Assembly
Clean
all
the
parts
thoroughly. Make sure
that
all
oil
passages
are
open.
Check
the
clearance between
each
rocker
arm and
the
shaft
by
checking
the I.
D.
of
the rocker
arm bore
and
the
O. D.
of
the
shaft.
If
the clearance
between
any
rocker arm
and
the
shaft approaches 0.006
inch (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 the
rocker arm.
Do
not attempt to true
this surface
by
grinding.
Check the
rocker
adjusting
screws and
the push
rod
end
of the
rocker arms
for
stripped
or
broken
threads,
and
the
ball end
of
the
adjusting
screw for
nicks,
scratches,
or
excessive
wear.
Check
for
broken
locating
springs
and
inspect
the
oil
drain
tube
for
cracks
or
sharp
bends.
Push
Rods
Check
the
ball
end
and
the
socket
end
of
the
push
rods
for
nicks,
grooves,
roughness,
or
excessive
wear.
The
push
rods
can
be
visually
checked
for
straight-
ness
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).
If
the
runout
exceeds
0.020
inch
at
any
point,
discard
the
rod.
Do
not
attempt
to
straighten
push
rods.
Cylinder
Heads
To
protect
the
machined
surfaces
of
the
cylinder
head,
do
not
remove
the
holding
fixtures
while
the head
is
off
the
engine.
CLEANING
AND
INSPECTION.
With
the
valves
in
stalled
to
protect
the
valve
seats,
remove
carbon de
posits
from
the
combustion
chambers
and
valve
heads
with
a
scraper
and
a
wire
brush.
Be
careful
not
to
scratch
the
cylinder
head
gasket
surface.
After
the
Holding
fixture'
PUSH
ROD
10O3-A
Fig.
3
Push
Rod
Runout
Typical
valves
are
removed,
clean
the
valve
guide
bores
with
a
valve
guide
cleaning
tool.
Use
cleaning
solvent
to
re
move
old
gasket
sealer, dirt,
and
grease.
Check the
head
for
cracks,
and
the
gasket
surface
for burrs
and nicks. Replace
the
head
if
it
is
cracked.
Do
not
plane
or
grind more
than
0.010 inch from
the
cylinder
head
gasket
surface. Remove
all burrs
or scratches
with an
oil
stone.
Cylinder
Head
Flatness
Check the flatness
of
the cylinder
head gasket sur
face (Fig. 4).
Specifications for flatness are
0.006 inch
maximum over
all,
or 0.003
inch in
any
6
inches.
Valve
Seat Runout
Check
the
valve seat
runout with an
accurate
gauge
(Fig. 5).
Follow the
instructions
of
the
gauge
manu
facturer.
The total runout
should not
exceed
0.0025
inch
(wear limit).
0(3)
CHECK
DIAGONALLY
(5)
CHECK
ACROSS
CENTER
Fig.
4
Cylinder
Head
Flatness
1O04-A