Westerbeke 8.0KW-60Hz Service Manual page 31

ENGINE INSPECTION
16. Crankshaft
a. Clearance between crankpin and connecting rod
bearing.
(1)
Install the bearing (upper and lower halves) and cap
to the big end of the connecting rod and tighten the
cap nuts to
the specified torque. Measure
the bore
in the bearing for crankpin as shown.
TIGHTENING TORQUE
25.7
±
1.8Ib·n
3.55 ± 0.25 Kg .,
34.8 ± 2.5 Nm
. MEASURING
8!l:
DIRECTION
MEASURING
THE.~~~
BORE IN THE
CONNECTING
ROO BEARINGS \
(2)
Measure the diameter of the
clearance between the
bearing.
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-VI
MEASURING :
DIRECTlQN _ ...
MEASURING THE
DIAMETER OF
THE CRANKPIN
to find the
connecting rod
DIAMETER OF CRANKPIN {NORMAL SIZE 1.89 in (48mm)
STANDARD 1.88779 ·1.88838 In (47.950 • 47.965mm)
CLEARANCE BETWEEN THE CRANKPIN AND THE CONNECTiNG ROD
BEARING
STANDARD 0.00098·0.00283 In (0.025 • 0.072mm)
LIMIT 0.00591.1n (0.150mm)
(3) If the clearance exceeds the limit, install a new
bearing and check the clearance again.
(4) If the clearance still exceeds the limit, grind the
crankpin to 0.25mm (0.0098 in), 0.5Omm (0.0197 in)
or 0.75mm (0.0295 in) undersize and use.a undersize
connecting rod bearing.
CRANKPIN UNDERSIZES
0.25mm {0.0098 In)
FINiSH.. 47.75·'·' mm (1.8799 •. "'"' in) .
0.50mm {0.0197 In)
FINISH 47 .50
,~,
mm (1.8701 . ..,,,. in)
0.75mm (D.0295 In)
FINISH 47.25·'·' mm (1.8602 .,.,." In)
A
CAUTION:
Grind al/ tlul crankplns of one
crankshaft to the same undersize.
Finish the crankpin fillets to a radius of 0.098 in
(2.5mm).
a.
Inspect the clearance between the journal and the main
bearing.
(1) Install the main bearing (upper and lower halves)
and the cap to the cylinder block and tighten the
cap bolts to the specified torque. Measure the
bore in the bearing for the journal.
TIGHTENING TORQUE: 38
±
1.8 Ib·n (5.25
±
0.25 kg·m)
, MEASURING THE
BORE IN THE MAIN
(2) Measure the diameter of the journal as shown to
find the clearance between the journal and main
bearing.
DIAMETER OF JOURNAL (STANDARD)
NOMINAL SiZE 2.05 in (52mm)
STANDARD 2.04665·2.04724 In (51.985· 52.000mm)
CLEARANCE BETWEEN JOURNAL AND MAIN BEARING
STANDARD' 0.00118·0.00303 in
(0.030· O.077mm)
LIMIT 0.00394 in (0.100mm)
-rb.
H
-VH
MEASURING THE
DIAMETER OF
THE JOURNAL
~ WESTERBEKE
Engines & Generators
25
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