Westerbeke 7.0 KW BGC -60Hz Technical Manual page 74

Grinding tolerance for cylinder block upper surface.
Cylinder Block Height 4.5 KW BCG
STO: 8.6575 - 8.6653 in.
(219.9 - 220.1 mm)
Umit: 8.6535 in. (219.8 mm)
Cylinder Block Height 7.0 KW BCG
&
BCGA
STO: 9.2874 - 9.2953 in.
(235.9 - 236.1 mm)
Umit: 9.2834 in. (235.8 mm)
4. Check for scratches or burns on the cylinder walls.
If necessary, repair by boring each cylinder or
replace the cylinder block.
5. Measure the wear on the cylinder bores at the six
positions shown in the figure to the right with an
inside micrometer. (The wear is the difference be-
tween the maximum and minimum diameters.) Ifthe
cylinder bores have worn beyond the specified wear
limit, the cylinder block requires boring to restore
each cylinder's true wall surface.
Standard Bore Diameter
4.5 KW BCG: 2.4409 - 2.4421 in.
(62.00 - 62.03 mm)
7.0KWBCG:
& BCGA
2.6220 - 2.6232 in.
(66.60 - 66.63 mm)
Wear limit: 0.0039 in. (0.10 mm)
Out-of-Roundness, Taper Umit:
0.0012 in. (0.03 mm)
8
,fr)
Front
+-
V
\~~
m : '
Jr
'~
c ' :
,
6. Check the ridge in the cylinder. If the engine has a large number of hours on it, a large cylinder ridge most
likely will be present. If a ridge exists, have the cylinders reamed to remove these ridges. Leaving these
ridges in the cylinder can break piston rings when the pistons are installed in the engine. In addition,
if
new piston rings are to be installed, have the cylinder walls deglazed (roughed up) so the rings may seat
properly.
Westerbeke Generators 70