WORKSHOP MANUAL - lombardini service

Disassembly / Reassembly
4
Connecting rod alignment
Using a gauge on a comparison plan, check the axial alignment by
placing the connecting rod on a V-blocks as shown.
Maximum Axial Mis-alignment = 0,015mm, Limit =0,030mm.
Minor mis-alignment may be corrected by skillfully and gradually
working the connecting rod between centers on a press.
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CYLINDERS
Reset the dial gauge with a calibrated ring: check the diameter D in
points 1, 2 and 3; repeat the same operation rotating the dial gauge
by 90° at the same heights.
Check any wear in zone X where the piston rings operate and if it is
greater than the 0.05 mm max limit given adjust the cylinder to the
next increased value.
75.000 mm max limit.
103
104
Cylinder, class
The pistons (A, B, C) locations are shown on the piston crown
while those for the cylinders are found on the crankcase in the
points shown by the arrows, see picture.
Note: The cylinders are not to be changed.
105
Cylinder roughness
Caution – Warning
Do not treat the cylinder’s internal surfaces with an emery
cloth.
The angle of the crossed processing marks must be between 45°
and 55°. These must be uniform and distinct in both directions.
Average roughness must be between 0.5 and 1 µm.
The whole surface of the cylinder affected by contact with the piston
rings must be rendered with the plateau method.
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FOCS Workshop Manual_cod. 1.5302.858_1° ed_ rev. 00
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