Maintenance Manual for J2 Sedan
Mechanical Part of Engine
79
piston diameter should be measured at the position shown in Figure.
c.
Calculate the boring size based on the piston diameter.
[Boring size]
＝
[outer diameter of piston]
＋
[clearance between piston and cylinder (0.02-0.04mm)]
－
[grinding margin (0.02mm)]
d. Boring each cylinder till it obtains the calculated boring size.
Attention:
■
To avoid the distortion due to heat during the boring course, bore the cylinders in following
sequence: Cylinder 2
→
Cylinder 4
→
Cylinder 1
→
Cylinder 3
e.
Grind the cylinder till it meets the final processing size (outer diameter of piston
＋
clearance
between piston and cylinder)
⑩
Diameter of Main Crankshaft Journal
Measure the main crankshaft journal by the outside micrometer.
Standard value: 48.0mm
If it exceeds the standard, please follow the rules of selection to replace.
⑪
Diameter of Main Journal of Connecting Rod
Measure the diameter of main journal of
connecting rod by using outside micrometer.
Standard values:43.0mm
Replace the connecting rod bearing shell if
measurement exceeds standard value.
⑫
Gap of Connecting Rod Bearing Shell
Note: Use the plastic divider to perform the
measurement.
a.
Clean any engine oil from the connecting rod
journal and connecting rod bearing shell.
b.
Put the plastic divider on the connecting rod
journal, and asset it to a length equal to
bearing shell width. The plastic divider must
be placed at the center of connecting rod
journal and be parallel with the axial line of
connecting rod.
c.
Lightly put the connecting rod cover to
specified place, and screw the bolt to
specified torque.
d.
Dismount the bolt, then take off the connecting rod cover slowly.
e.
Measure the pressed portion of plastic divider at the widest point by the scale which is printed on
the plastic divider bag.
Fig.1.1.066
Fig.1.1.065
Dial Indicator
