Tractor 6-cylinders engine

1 – crankcase; 1 – oil pump; 3 – torsional vibrations damper; 4 – crankshaft pulley; 5 – fan driving belt; 6 – valve-timing gearing cover; 7 – tensioning jockey; 8 – alternator driving belt; 9 – fan; 10 – water pump; 11 – thermostats housing; 12 – piston pin; 13 – connecting rod; 14 – piston; 15 – cylinder sleeve; 16 – cap hood (2 off); 17 – cylinder head cover (2 off); 18 – cylinder head (2 off); 19 – cylinder head gasket (1 off); 20 – cylinder block; 21 – rear sheet; 22 – flywheel; 23 – counterweight; 24 – cover; 25 – crankshaft; 26 – piston cooling jet ; 27 – oil pick-up.

The tractor is equipped with six-cylinder, in-line, four-stroke turbo-charged, liquid-cooled diesel engine with direct injection of fuel.
The tractor engine is cranked by an electric starter.
The tractor engine 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) is designed as a monoblock and constitutes a rigid iron casting.
Six replaceable sleeves (15) made of special cast iron are installed in the cylinder block bores.
The sleeve is installed in the cylinder block with referring to two centring belts. At the upper belt, the sleeve is re-strained with a shoulder, while at the bottom one it is packed with two rubber rings.
At the bottom, the cylinder block is closed with a crankcase (1) cast of aluminium alloy.
The two interchangeable Cylinder Heads (18) (one per three cylinders) are iron cast.

The cylinder heads are fitted with insertion valve seats made of high-temperature and abrasion-resistant alloy. The injectors (14) (three pieces per each cylinder head) are mounted in the cylinder heads.
The sealing of the cylinder head-to-engine block joint is ensured by the gasket (19) made of asbestos-steel cloth. The bores for the cylinder sleeves and the oil passageway are edged with sheet steel. When assembling the engine at the manufacturing plant, the cylinder holes in the gasket are additionally edged with fluoroplastic rings.

The Crank Gear includes a crankshaft (25), together with main rod and connecting rod bearings, a flywheel (22), pistons (14) assembled with piston rings and pins, and connecting rods (13).
The Crankshaft is made of steel, sup-ported on seven bearing saddles and fitted with counterweights. The crankpins are provided with pockets intended for additional centrifugal cleaning of oil. These are closed with threaded plugs.
The front-end of the crankshaft is fitted with the pinions for driving the valve control and oil pump, pulley for driving the water pump, alternator and air-conditioner compressor.
To reduce the amplitude of torsional vibrations of the crankshaft, the pulley is equipped with a liquid-type vibration damper (3).

The Engine Piston is made of aluminium alloy. A combustion chamber is made in the piston crown. Three compression piston rings and one oil wiper ring with an expander are installed in the upper part of the engine piston. The top compression piston ring is of a trapezoidal section, the other two compression rings are taper-faces. A non-resistive spacer is installed under the top ring.

1 – camshaft; 2 – tappet; 3 – valve; 4 – valve guiding bush; 5 – pushrod; 6 – turbocharger; 7 – rocker arm; 8 – roller; 9 – spring retainer (disk); 10 – split cones; 11 – inner spring; 12 – outer spring; 13 – sup-port; 14 – injector; 15 – fuel pump; 16 – fuel hand booster-pump; 17 – plug for bleeding air from the fuel pump head; 18 – sealing collar.

The Connecting Rod is an I-section steel part, with a bushing pressed into its top end. For lubricating the piston pin, the top end of the connecting rod and the bushing are provided with drilled pas-sages. The bottom end consists of the bottom part of the rod and the cap which bear the same markings. The connecting rod caps are not interchangeable. Besides, the connecting rods have group designations of the mass groups of the top and bottom ends; these are marked on the end-face of the top end of the connecting rod. The engine shall be equipped with the connecting rods of the same group only.
Liners of the Main- and Crankpin Bearings of the crankshaft are thin-walled parts made of a bimetal strip. The liners are manufactured in two sizes as to their inner diameter in accordance with the nominal size of the crankshaft necks.

The Flywheel is made of cast iron and bolted to the crankshaft flange. A steel toothed rim is pressed onto the flywheel.
The Valve Control consists of the timing gears, camshaft, inlet and outlet valves as well as their fitting and driving parts.
The Camshaft is driven from the crank-shaft through valve timing gears and rides on four supports.
The Tappets (2) are steel members with spherical bottoms. The camshaft cams are made with a slight tilt; hence, when in operation, the tappets are forced to rotate.
The Tappet Pushrods (5) are made of a steel bar. The downwardly concave part of the tappet and the push-rod cup are hardened.

The Valve Rocker Arms (7) are made of steel and rock on the rollers installed in supports. The rocker arm roller is hollow, with six radial bores for arm lubrication. Displacement of the rocker arms along the roller is restricted by spreader springs.
The Inlet and Outlet Valves (4) are made of high-temperature steel and free to move in their guide bushes. The bushes are press-fitted in the cylinder heads. Each valve closes under the force of two springs: the outer (12) and the inner (11), respectively, fixed on its stem by means of a valve spring retainer (9) and valve locating split cones (10).
Sealing collars (18) installed on the valve guiding bushes keep oil from leaking down into the engine cylinders through gaps between the valve stems and the guiding bushes.

1 – piston; 2 – insert of a “non-resist” type; 3 – top compression ring; 4 – compression ring; 5 – oil wiper ring with an expander.