Westerbeke W-46 - Valve Guides and Valve Seats

INSPECTION/REPAIR
Valve Guides and Valve Seats
1. Check each valve for carboning,
burning, wear or other defects
on the head: also check cap end
and stem for cracks. Replace
the valve if damaged.
2.
Valve guide ~
remove~
.~.sc
it -
.
.
II
~-
30
-~
158
188
(Dimensions in rnrn)
Material: S53C
;,c
·-' 12•
Check each valve guide for
wear. Remember, the guide wears
more rapidly at the ends.
Measure the inside diameter of
the guide at each end and at
the middle from both direc-
tions. Measure the outside
diameter of each valve stem.
If the measurement exceeds the
repair limit given in the table
below, replace the valve guide.
Valve guide removal tool wear on valve guide
3.
Valve face and valve seat.
Check valve face and valve seat for wear and contact.
valve face is worn excessively, reface it by using
refacer. To reface the valve, proceed as follows:
Specifications
Unit· mm (in)
.
Item
Standard
Service
limit
Clearance
Intake
0.055 -0.085
0.15
of valve
(0.00217-0.00335) (0.0059}
stem in
O.o?0-0.100 0.20
valve guide
Exhaust
(0.00276 -0.00394)
(0.0079)
Valve guide
18 ±0.3
length out-
(0.709 ± 0.012)
side hole
8-0.045
-0.060
-0.1
Intake
(0315 -0.00177)
(-0.004)
Valve stem
. -0.00236
diameter
-8-0.060
Exhaust
-0.080
-0.15
(0 315 -0.00236)
(-0.0059)
. -0.00315
Specifications
Item
Nominal
Sti!ndard
Repair
Service limit
value
limit
Angle
. 30°
Sinkage
±0.2
1.3
Valve
0.8 (0.031)
(±0.008) (0.051)
seat
Width
1.4 (0.055)
±0.14
1.6
(±0.0055)
(0.063)
±0.1
Reface up to
angle
Valve margin
1.7 (0.067)
1.2
(±0.004)
{0.047)
Engines & Generators
16
If the
a valve
Unit: mm (in.)
margin