Lombardini LDW 502, Руководство по обслуживанию

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service manual
mod. 051135
6
D
A 0 0 0 , 2 7 ÷ 0 9 9 , 1 7 0 4 9 , 1 7 ÷ 0 3 9 , 1 7
7 0 , 0 ÷ 5 0 , 0
B 0 0 1 , 1 7 ÷ 0 0 0 , 2 7 0 5 9 , 1 7 ÷ 0 4 9 , 1 7
C 0 2 0 , 2 7 ÷ 0 1 0 , 2 7 0 6 9 , 1 7 ÷ 0 5 9 , 1 7
R 0 2 1 , 2 7 ÷ 0 0 1 , 2 7 9 4 0 , 2 7 ÷ 1 3 0 , 2 7
6.2.2 Dimensional check and overhaul of
cylinders
1 - Place the engine block on the workbench.
2 - Using a micrometer, measure the diameter
at points 1-2-3 (see diagram).
3 - Rotate the micrometer 90° and remeasure.
If ovalization or wear is greater than
0.05mm, the cylinder must be ground .
Important
– The increases recommended by the
manufacturer for the cylinder head 0.5
and 1 mm.
– When grinding make sure that the
working angle is 45-55° and that the
average roughness is Ra=0.5-1.
– Do not sand the internal surfaces of the
cylinders using emery cloth.
– Protect the contact surfaces with
lubricant oil, to prevent them from
rusting
The table shows the reference values and their class (only
applies to new engines).
6.2.3 Dimensional check and overhaul of
pistons
1 - Clean the piston thoroughly (D).
2 - Using a micrometer, measure the piston
9mm from the base of the skirt.
3 - Check the table to identify the class from
the values detected.The class letter is
engraved on the piston,
If clearance between cylinder and piston
is greater than 0.05mm, the piston and
sealing rings must be replaced, and
rematched according to the diameter of the
ground cylinders “see Table of cylinder-
piston classes and dimensions”).
Important
Before replacing the pistons, check that the
weight difference does not exceed 4g to
prevent weight imbalances.
Important
Pistons with nominal diameter are supplied only in
class (A) spares. Those uprated by 0.5 and 1 mm have
the uprating referance (ø72.5 e ø73) engraved on the
upper part of the piston (see “Table of cylinder - piston
classes and dimensions”).
Protect the contact surfaces with lubricant oil, to prevent them
from rusting.
Table of cylinder - piston classes and dimensions
Dimension
class
Ø Pistons
(mm)
Ø Cylinders
(mm)
clearance
(mm)
OVERHAULS AND TUNING