Crankpin And Crank Journal - Grind - Mitsubishi S12A2 Service Manual

5.5.1 Crankpin and Crank Journal - Grind

When using the undersize bearing, grind to the standard
value corresponding to undersize bearing to be used.Do not
change the fillet radius and bearing journal width when
grinding.If a remarkable decrease in hardness is found,
quench the crankshaft again and inspect it with the magnetic
particle inspection.
After grinding, measure the width of crankpin journals and
rearmost crank main journal.
Item
Crankpin outside diameter
Crankshaft main journal outside diame-
ter
Parallelism
Roundness
Cylindricity
Pin and
journal Pin
Fillet radius
Journal
Hardness
Finishing surface rough-
ness
Angular deviation between pins
Chapter 6 INSPECTION AND REPAIR OF BASIC ENGINE
Nominal Size
value
Standard
0.25 mm
[0.0098 in.]
ø104 mm 0.50 mm
[4.09 in.] [0.0197 in.]
Under
size
0.75 mm
[0.0295 in.]
1.00 mm
[0.0394 in.]
Standard
0.25 mm
[0.0098 in.]
ø130 mm 0.50 mm
[5.1180 in.] [0.0197 in.]
Under
size
0.75 mm
[0.0295 in.]
1.00 mm
[0.0394 in.]
- -
- -
- -
R7
-
[0.28]
R7
-
[0.28]
- -
- -
- -
Measurement
Measurement
point
direction
Crank Journal Outside Diameter - Measure
Standard value
103.900 to 103.920 mm
[4.0904 to 4.0912 in.]
103.650 to 103.670 mm
[4.0806 to 4.0814 in.]
103.400 to 103.420 mm
[4.0708 to 4.0716 in.]
103.150 to 103.170 mm
[4.0609 to 4.0617 in.]
102.900 to 102.920 mm
[4.0511 to 4.0519 in.]
129.880 to 129.900 mm
[5.1133 to 5.1140 in.]
129.630 to 129.650 mm
[5.1034 to 5.1042 in.]
129.380 to 129.400 mm
[5.0936 to 5.0944 in.]
129.130 to 129.150 mm
[5.0837 to 5.0845 in.]
128.880 to 128.900 mm
[5.0739 to 5.0747 in.]
Deviation of 0.01 [0.0004] or less over
entire pin length
Diameter difference 0.01 [0.0004] or less
Diameter difference 0.01 [0.0004] or less
6.8 to 7.0 mm
[0.268 to 0.276 in.]
6.8 to 7.0 mm
[0.268 to 0.276 in.]
Hv > 620
Ra0.2μm
±0.3°
Limit value
103.860 mm
[0.019 in.]
103.610 mm
[4.0790 in.]
103.360 mm
[4.0692 in.]
103.110 mm
[4.0593 in.]
102.860 mm
[4.0495 in.]
129.840 mm
[5.1117 in.]
129.590 mm
[5.1018 in.]
129.340 mm
[5.0920 in.]
129.090 mm
[5.0822 in.]
128.840 mm
[5.0723 in.]
0.03 mm
[0.0012 in.]
0.03 mm
[0.0012 in.]
0.03 mm
[0.0012 in.]
-
-
-
-
-
6-25