Operating Instructions - Belarus 1221B.2 Operator's Manual

BELARUS-1221.2/1221В.2/1221.3
DESCRIPTION AND OPERATION
Engine
The tractor is equipped with a Д-260.2/Д-
260.2С/Д-260.2S2 six-cylinder in-line in-
line, four-stroke turbo-charged, direct-
injection liquid-cooled diesel engine (with
a charge air cooler with coolant for the Д-
260.2S2 engine).
The engine is started by means of an
electric starter.
The engine (Fig. E-1, E-2) consists of a
cylinder block, two cylinder heads, crank
mechanism, valve control as well as feed,
lubrication, cooling and starting systems
and electric equipment.
The cylinder block (20) (Fig. E-1) is de-
signed as a monoblock consisting of a
rigid iron casting.
Six replaceable sleeves (15) made of
special cast iron are installed in the cylin-
der block bores.
The sleeve is installed in the cylinder
block at two centring 'belts'. At the upper
belt the sleeve is restrained with a shoul-
der, while at the bottom one it is packed
with two rubber rings.
From the bottom, the cylinder block is
closed with a crankcase casting (1) made
of aluminium alloy.
The two interchangeable cylinder heads
(18) (one per three cylinders) are iron
cast.
The cylinder head contains the inserted
valve seats made of heat and abrasion
resistant alloy. In the cylinder head, the
injectors (14) (Fig. E-2) (three per head)
are installed.
The provide the tightness of the joint be-
tween the cylinder heads and the cylinder
blocks, a gasket (19) made of asbestos-
steel cloth is inserted. The bores for the
cylinder sleeves and the oil passageway
are edged with sheet steel. When as-
sembling the engine at the manufacturing
plant, the cylinder holes in the gasket are
additionally edge-formed
rings.
The crank gear (Fig. E-1) includes a
crankshaft (25), together with main- and
connecting-rod bearings, a flywheel (22),
pistons (14) in assembly with piston rings
and pins, and connecting rods (13).
The crankshaft is a steel member made
with counterweights and supported on
seven bearing saddles. Crankpins are
made with pockets intended for additional
centrifugal cleaning of oil. They are
stopped with threaded plugs.
Valve timing drive and oil pump drive
gear as well as a water-pump, alternator
and air-conditioner compressor (if in-
stalled) drive pulley are mounted on the
crankshaft front-end.
To reduce the crankshaft torsional vibra-
tion amplitude, the pulley is fitted with a
liquid-type torsional vibration damper (3)
(Fig. E-1).
The piston is made of aluminium alloy. A
combustion chamber is made in the pis-
ton crown. Three compression piston
rings and one oil ring with an expander
are installed in the upper part of the pis-
ton. The top compression piston ring has
a tapered face. A "non-resistive" spacer is
installed under
70
Description and operation
with Teflon
the top ring.