The measurements must be made for each single cylinder at
three different heights up the liner and on two planes at right
angles to each other: one parallel to the longitudinal axis of
the engine (B) and the perpendicular (A); the greatest wear
is generally found on this last plane with the first
measurement.
On finding ovalization, taper or wear, go ahead and
bore/grind and finish the face of the cylinder liners. The
refacing of the cylinder liners should be done in relation to
the diameter of the pistons supplied as spare parts oversized
by 0.4 mm of the nominal value and to the prescribed
assembly clearance.
18837
87781
Figure 68
Figure 69
Once the engine removal is complete, carefully clean the
cylinder block. For the cylinder block transportation use the
suitable rings.
Carefully check that the crankcase has no cracks in it.
Check the state of the plugs. If they are rusty or there is any
doubt about their seal, replace them. Examine the surfaces
of the cylinder liners; they must show no sign of meshing,
scoring, ovalization, taper or excessive wear. The inside
diameter of the cylinder liners is checked, to ascertain the
extent of ovalization, taper and wear, using the bore meter
99395687 (1) fitted with a dial gauge previously reset on the
ring gauge of the diameter of the cylinder liner or on a
micrometer.
REPAIRS
CYLINDER BLOCK
Checks and measurements
Figure 70
* Surface roughness parameters:
R1 =
4
÷ 10 µm
Rz
=
3
÷ 8 µm
Ra
=
0.3
÷ 0.6 µm
W1 <
2
µm
Permissible surface porosity for machined cylinder
(see Figure 71)
ZONE B1 = Area of greatest mechanical stress,
segment/liner
contact:
No.2
non-continuous
porosities
are
permissible max. 0.5x0.5.
ZONE B2 = Surface involved in segment rubbing:
No.2 non-contiguous porosities are
permissible max. 1x0.8.
C
C
100%
100%
87782
Figure 71
87783
measurement
measurement
measurement
536
F1C ENGINE
D
AILY
Base - May 2004