Measuring Clearance Between Connecting Rod Bearing And Crankpin - Mitsubishi Heavy Industries SL Series Service Manual

4.8 Measuring clearance between connecting
rod bearing and crankpin
When grinding crank pins, be sure to grind all the pins
to the same size.
Finish the fillet radius to the specified dimension.
(1) Reassemble the bearing into the big end of the
connecting rod.
(2) Tighten the connecting rod cap bolts to the specified
torque.
(3) Measure the inside diameter of the connecting rod
bearing.
(4) Measure the outside diameter of the crank pin.
(5) Calculate the clearance from the difference between the
inside diameter of the connecting rod bearing and
outside diameter of the crank pin.
(6) Replace the connecting rod bearing if the clearance
exceeds the limit.
(7) Measure the clearance between the connecting rod
bearing and the crank pin again. Use the undersize
bearing if the limit is exceeded.
(8) If an undersize bearing is used, grind the crank pin to
the specified undersize.
Item Nominal
Pin outside ø 48 mm
diameter (STD) [1.89 in.]
Oil clearance -
Item Undersize
0.25 mm
[0.0098 in.]
Crankpin 0.50 mm
undersize [0.0197 in.]
0.75 mm
[0.0295 in.]
Standard Limit
47.950 to 47.965 mm
-
[1.8878 to 1.8884 in.]
0.025 to 0.072 mm 0.150 mm
[0.0010 to 0.0028 in.] [0.0059 in.]
Finish dimension
-0.035
ø 47.75 mm
-0.050
-0.0014
[1.8799 in.]
-0.0020
-0.035
ø 47.50 mm
-0.050
-0.0014
[1.8701 in.]
-0.0020
-0.035
ø 47.25 mm
-0.050
-0.0014
[1.8602 in.]
-0.0020
INSPECTION AND REPAIR OF BASIC ENGINE
Measuring
Measuring
directions
points
Measuring connecting rod bearing inside diameter
Measuring Measuring
directions points
Measuring crankpin outside diameter
Finish dimension of fillet radius
32.4 to 37.3 N·m
{3.3 to 3.8 kgf·m}
[24 to 27 lbf·ft]
R2.5 mm
[0.098 in.]
6-15