Figure 11B-62. Refacing Exhaust
Valve
When a new valve insert is installed or
an old insert is reconditioned, the work
must done with a grinding wheel (see
The eccentric grinding method for re-
conditioning valve seat inserts is recom-
mended. This method produces a finer,
more accurate finish since only one point
Figure 11B-63. Reconditioning Valve
of the grinding wheel is in contact with
Seat Insert
the valve seat at any time. A micrometer
feed permits feeding the grinding wheel
NOTE
i n t o the work 0.001" at a time.
Do not permit the grinding wheel
Eccentric valve seat grinder set J 7040,
to contact the cylinder head when
which includes the grinder, dress stand
grinding the insert. When an in-
and pilot, and dial gauge, is used to
sert has been ground to the extent
grind the inserts. An adaptor set which
that the grinding wheel will con-
includes the grinding wheels and pilot is
tact the cylinder head, install a
used with the grinder.
new insert.
Adaptor set J 6390-02, consists of the
following:
The maximum amount the exhaust valve
should protrude beyond the cylinder
1 . Pilot, tool J 7659-1
head (when the valve is closed) and still
maintain the proper piston-to-valve
2 . Grinding wheel (15), tool J 6390-2
clearance is shown in Figure 11B-61 on
page
11B-39.
Grinding
will
reduce
the
3. Grinding wheel (31), tool J 6390-3
thickness of the valve seat insert and
cause the valve to receded into the cyl-
4. Grinding wheel (60), tool J 6390-4
inder head. If, after several grinding
operations, the valve recedes beyond the
Grind the inserts as follows:
specified
Iimits,
replace
the
valve
seat
insert.
1. First apply the 31 grinding wheel on
the valve seat insert.
When occasion requires, the grinding
w h e e l may be dressed to maintain the de-
2. Use the 60 grinding wheel to open
sire seat angle with the dressing tool
the throat of the insert.
provided with the grinder set (see
3. Grind the top surface of the insert
with the 15 wheel to narrow the width of
4. After grinding has been completed,
the seat to the dimensions shown in
clean the valve seat insert thoroughly
Figure 11B-61 on page 11B-39. The 31
with fuel oil and dry it with compressed
face of the insert may be adjusted rela-
air. Set the dial indicator J 8165-2 in
tive to the center of the valve face with
t h e 15 and 60 grinding wheels.