Valve Seats
ACTUAL
SEATING
SUBFACE
VALVE
SEAT
PRUSSIAN
Reconditioning
1. Renew the valve seats
in the cylinder
head using a
valve seat cutter.
NOTE: lf
guides
are
worn
(see
page
6-24),
replace
them
(see
page
6-251 before cutting
the valve seats,
2. Carefully
cut a
45'
seat,
removing only enough
material to ensure a
smooth and concentric seat.
3.
Bevel the upper edge
of the seat
with
the
30o cutter
and the
lower edge of the
seat with the 60' cutter.
Check width of seat and
adjust accordingly.
4. Make one
more very
light
pass
with the
45"
cutter
to
remove
any
possible
burrs
caused by the other
cut-
ters.
Valvo Seat
Width
llntake
and
Exhaustl:
Standard:
1.25
-
1.55 mm
{0.049
-
0.061
inl
Servics
Limit:2.0
mm
10.08
inl
SEAT
WIDTH
After
resurfacing the seat,
inspect for even
valve
seating: Apply
Prussian Blue compound
to the
valve
face, and
insert valve
in
original
location
in the
head, then lift it and snap
it closed against
the seat
severaltimes.
!
6-27
7.
The
actual
valve seating surface, as
shown by the
blue compound, should be
centered on the seat.
.
lf it is too high
(closer
to the
valve stem),
you
must make a
second cut with the 60" cutter
to
move it down, then one
more cut with the
45'
cutter
to restore seat
width.
.
lf it is too low
(closer
to the valve edgel,
you
must make a second
cut with the 30' cutter to
move it up, then one
more cut with the
45"
cutter
to restore seat width.
NOTE: The
final cut should always be
made with
the
45'
cutter.
Insert intake and exhaust
valves in the
head
and
measure valve stem
installed height
Intako
Valve Stem Install€d
Height:
Standard
(New): /$.765
-
'11.235
mm
{1.604It
-
1.6234 in}
Service
Limit:
ill.il85
mm
(1.6:133
inl
Exhaust
Valvo Stem lnstalled
Height:
Standard {Newl:
,12.765
-
i|:|.235
mm
11.6a37
-
1.1022 in1
Service
Limit
/B.il85
mm
(1.7120
inl
lf valve stem
installed height
is
over
the service
limit,
reDlace valve and
recheck. lf still over the
ser-
vice
limit, replace cylinder
head; the
valve seat in
the head is too deeo.
8.
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