Westerbeke W-46 - Page 19

valve Refacer
INSPECTION/REPAIR
·a. Set the valve refacer to an
angle of 45 degrees.
b. When grinding the valve,
remove the least amount of
material to properly reface
the valve and, if the margin
is less than 1.2 nun (0.047
in.), replace the valve.
Valve seat cutter.
Repair an excessively worn
valve seat by using a valve
gtinder or valve seat
cutter.
c. When using a valve seat
cutter, carefully apply a
uniform pressure to the
valve seat to prevent uneven
cutting. After cutting,
reface the seat by rotating
the cutter with No.400 sand-
paper placed between the
cutter and seat.
d. If valve seat width is over-
cut, repair it using a
30 degree cutter. If valve
seat width exceeds 1.6 rom
(0.063 in.) dtie to wear,
replace the seat. Also
replace the seat when valve
sinkage exceeds 1.3 mm
(0.051 in.).
valve Seat Installation
Installing 1
intake valve
inserts
3
Installing 4
exhaust
valve inserts
Exhaust
5
Intake
(exhause)
(intake)
head
l-Caultking/ body
2-Valve insert
3-Cylinder head
4-Valve guide
5-Caulking ring
intake valve
insert caulking
tool
Heat cylinder head to a temperature of 80"C to lOO•C {176"F to 212"F),
and cool the valve seat sufficiently in ether or alcohol containing
dry ice. Valve seat may be cooled in liquid nitrogen.
P.~;:ess the valve seat into cylinder head and leave the head and seat
until they cool down to room temperature.
Specifications
Unit:
mm (in.)
A
8 c
0
33 +0.02
41+0.025
7.8 ±0.1
2.8 ±0.1
Valve seat
0
0 .
dimensions
(1.30 +g.0008)
(1.61 +g.00098)
(0.307 ± 0.004)
(0.11
± 0.004)
...
17