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16
Charter two Main installing requirements
Installation of the crankshaft
Figure 1 Tightening order of the main bearings
During crankshaft installation, the main
bearing bolts should be tightened from thrust
gear (the third gear) to both ends in order, and
in three steps: First, tighten to 60~80N.m;
Then, tighten to 160~180N.m;
Finally, tighten to 220~260N.m.
During every time, the crankshaft should be
rotated to check the mobility. It should be able
to rotate freely after the final tightening. The
axial clearance should be between 0.1 and
0.27mm.
Installations of the piston and the connecting rod
Figure 2 Orientation of the gap of piston rings
When installing the piston rings, put the surfaces
marked upward (the second positive twist ring inner
fillet upward). During positioning the piston-connecting
rod assembly into the cylinder bore, stagger the joints
in turn as shown in Figure 2, and put the arrow marked
on the top surface of piston towards the front end of
the engine. Remember spreading some clean oil before
tightening connecting-rod bolts. The tightening torque
should be between 160~200N.m, and completed in
three steps:
First, tighten to 50~70N.m;
Then, tighten to 100~120N.m;
Finally, tighten to 160~200N.m.