Valve Seats - Westerbeke 9.0 BCG Technical Manual

4. Check of each valve's head stock thickness.
Replace the valve if it is beyond the allowable
limit.
Valve Head Stock Thickness Limit
Specified Limit
Intake: 0.35 - 0.59 inches
(0.9 - 1.5 mm)
Exhaust: 0.047 - 0.071 inches
(1.2 -1.8
mm)
5.
Check for excessive grooves at the end
of
the
valve stem.
Valve Seats
1.1 nspect the valve's contact surface for pitting and
damage.
2.
Measure each valve's contact width.
Contact Width (Both Intake and Exhaust)
BCG
4.0KW 0.047 - 0.063
inches
(1.2 -1.6 mm)
BCG
6.5KW
and BTG
9.0KW
0.39 - 0.071
inches
(1.0 -1.8
mm)
NOTE: Check the valve's contact area and
position by applying a thin coat of Prussian
Blue or red lead to the valve's seat and push
the valve upward into cylinder head's seat
(apply only enough pressure to assure a
press fit). Under its own weight, let the valve
drop away from the cylinder head. Perform
this operation two or three times until the
valve's contact surface can be accurately
measured.
Check if the valve seat's contact face con-
tacts the center position of the valve's con-
tact face. Do not rotate the valve.
89
1\
lJl
If
/
Valve stem outer diameter I
--If--
Valve head stock thickness
1\
1/
/
C~eck
for excessive
groov~_/'
Seat width
Westerbeke Generators