Avtodizel ???-238??, Operating Instructions Manual, Page: 28 / 254

28
The crankshaft main bearing and connecting rod big end shells
(fig. 11) – replaceable thin-walled ones, have the steel basis and work-
ing layer of lead bronze.
The upper and lower shells of the crankshaft main bearing are
not interchangeable. On upper one there are the hole for oil supply and
groove for oil distribution. Both shells of the connecting rod big end
are interchangeable.
LINER, PISTON, PISTON RINGS
AND SEALING RINGS
CYLINDER LINER
Cylinder liners - “wet” type, are made of special cast-iron. The
liners are installed by it mate belts in borings of the cylinder block and
from above pressed through lug and gasket with cylinder heads.
The
height of the liner lug above cylinder block surface of engines:
ЯМЗ
-238
БЕ
2,
ЯМЗ
-238
ДЕ
2 — 1,6
035 . 0
065 . 0
+
−
mm.
ЯМЗ
-238
БЕ
,
ЯМЗ
-238
ДЕ
— 0,1
065 . 0
035 . 0
+
−
mm.
For the engines
ЯМЗ
-238
БЕ
,
ЯМЗ
-238
ДЕ
the liners with the
following design features can be installed:
1 The liner 236-1002021-
А
5. Surfaces of liner are bonderi-
zated. The bonderizated layer improves the wearing-in char-
acteristic, increases wearlessness of a surface. The external
difference of bonderizated liner from non- bonderizated one
- considerably more dark (from darkly-grey up to black)
colour of an outside surface. The upper end face of liner lug
is made with acting part outside to inner surface of liner
with lug height 12.1 mm (for steel-asbestos gasket of gas
joint).
In the lower part of liner three grooves for anti-cavitation
and seal rubber rings
are made.
2 The liner 236-1002021-
А
. All the same to above, but non-
bonderizated.
For engines
ЯМЗ
-238
БЕ
2,
ЯМЗ
-238
ДЕ
2 the liner
7511.1002021-01 is used. It is bonderizated.