Ford Thunderbird 1957 - Reaming Valve Guides; Refacing Valve Seats; Valve Seat Width; Valve Seat Runout

1-12
Chapter
1
General
Engine
Service
Runout
Gauge
1005-
A
007-A
Fig.
5
Valve
Seat
Runout
Typical
Fig.
7
Reaming
Valve
Guides
Valve
Seat
Width
Measure
the
valve seat width
(Fig.
6).
The
intake
valve seat width
limits are
0.060-0.080
inch
and
the
exhaust
valve
seat
width
limits are 0.070-0.090
inch.
REAMING VALVE
GUIDES.
If
it becomes
necessary
to
ream
a valve
guide (Fig.
7)
to
install a valve with
an
oversize
stem,
a
reaming
kit
is
available which contains
the
following
reamer and pilot combinations: a
0.003-
inch
O.S.
reamer with a standard
diameter
pilot,
a
0.015-
inch
O.S. reamer with a 0.003-inch O.S.
pilot,
and
a
0.030-inch reamer with a
0.015-inch
O.S. pilot
When
going
from
a
standard
size valve
to
an over
size
valve,
always
use
the reamers
in
sequence.
Always
grind
the valve
seat after
the
valve
guide
is
reamed.
REFACING VALVE SEATS.
Refacing
of
the valve
seats
should
be
closely
coordinated
with the
refacing
of
the valve
face
so
the
finished
seat
will match the
valve
face
and
be centered.
This is
important so
that
the valve
and seat
will have
a
good
compression
tight
fit.
Be
sure
that the
refacer
grinding
wheels
are
proper
ly
dressed.
Grind
the
valve seat to
a
true
45
angle (Fig. 8).
Remove
only
enough
stock
to
clean
up
pits,
grooves,
or
to
correct the
valve
seat runout.
After
the seat is
ground,
measure
the
seat
width
(Fig.
6).
Narrow the
seat,
if
necessary
to
bring
it
within
limits.
If
the
valve
seat
width
exceeds
the
maximum
limit,
remove enough
stock from the
top
edge and/or
bottom
edge
of
the
seat to
reduce
the width
to
specifications
(Fig.
8).
Use a
30
angle
grinding
wheel to
remove
stock
from the
bottom
of
the
seat
(raise
the
seat).
Use
a
60
angle wheel to
remove
stock from
the
top
of
the
seat
(lower the seat).
The finished
valve
seat should contact
the approxi
mate
center
of
the
valve
face. To
determine where the
valve
seat
contacts the
face,
coat
the
seat
with Prussian
blue,
then
set
the
valve
in
place.
Rotate
the
valve
with
Seat
Width Scale
TO
REMOVE
STOCK
FROM
TOP
OF
SEAT,
USE
60
WHEEL
TO
REMOVE
STOCK
FROM
BOTTOM
OF
SEAT,
USE
30
WHEEL
1006-
A
VALVE SEAT
WIDTH:
INTAKE
0.0600.080
EXHAUST
0.0700.090
1008-
A
fig,
6
Valve
Seat
Width
Fig.
8
Valve
Seat
Refacing