YaMZ 240- versatile powerful engine worthy of special attention. It began to be produced by the Yaroslavl Motor Plant in the early 70s of the 20th century. The power of the first YaMZ240 engines did not exceed 360 hp, which was not at all a bad indicator for that time. By the way, according to pediviki, the power of various modifications of the YaMZ240 ranges from 360 hp to 800 hp. In general, in fact, this is a twin YaMZ236, fitted for cars that need high-power engines.

The beauty of this engine lies in the rather high reliability and the large herd hidden in this motor. Great power YaMZ 240 is provided by 12 cylinders, each with a diameter of 13 cm and a piston stroke of 14 cm. The rest of the puzomerki I think it will be unnecessary to write.
Since my experience with these motors is to repair those that are on the K-701, I will write further from this. So, I'll start with the advantages of YaMZ-240:

• power - is provided by 12 cylinders, since the engine is four-stroke, the cylinders fire in threes. Due to the large power reserve, the overall load on engine parts is reduced.
• long service life - YaMZ240 used to go to K-701 for 5-7 years, this indicator largely depends on the driver, if he provides the engine with proper care, then the motor will repay him with a long service life. This care consists in very simple operations: timely replacement of oil and oil filters; control that diesel fuel does not go into oil; timely replacement or cleaning of air filters to reduce wear on the CPG.
• crankshaft main bearings - roller! do not require replacement when repairing the engine, they are almost eternal.
• the cooling fan drive is a hydraulic clutch, it was undoubtedly very objective from the point of view of the designers to install a hydraulic clutch, which is driven through a splined shaft engaged with the crankshaft. Over the years, the splines on the shaft wear off, and it needs to be replaced, but this happens after 20-25 years of operation. In terms of reliability, such a mechanism fits perfectly.
• Cylinder head cracks are the exception rather than the rarity. I think many people know about the sore heads 236x and 238x - cracks from the nozzle hole to the valve seat. YaMZ240 does not suffer from such a disease.

The disadvantages I think include the following:

• the complexity of the repair - what does it cost to remove the rear flange of the crankshaft, to which the flywheel is screwed, for me and my puller, each successful such operation is a real feat. But it's one thing to remove it, another thing to put it back to the end in order to press the oil-reflective washer and not fry the oil seal. Also, special skills are required to pull the crankshaft out of the YaMZ240 and then clean it.
• lubrication system - the very sophisticated lubrication system of the YaMZ240 quite often causes the engine to wedge or knock. This happens because the lubricant supply to the crankshaft occurs through the hole in the nose of the crankshaft, and is supplied through the entire crankshaft to the very last neck. So, if for some reason the oil pressure in the system drops, then oil starvation will begin on the sixth crankshaft journal and there will be a risk of a knock or crankshaft wedge.
• the number of spare parts needed for overhaul of the engine, or rather their cost, which will only cost a piston ...
• a sudden failure is possible due to poor-quality repairs or low-quality spare parts, engine spacing or a fist of friendship. All this can lead to high costs for engine repairs up to replacing the block or crankshaft, or both at once, and they are not very cheap.
• There is a myth about the high fuel consumption of the YaMZ240 compared to the same YaMZ238, but it is worth noting here that the K701 is more confident and faster than the K700 when plowing. So I think fuel consumption will be justified due to the time saved, but there will always be people who will prove otherwise, this is purely my point of view.

At all YaMZ240 engine worthy of respect, because it can hold out for quite a long time under the control of some kind of ruthless asshole. There were so many cases, and they drove without oil and without water, and with twisted liners and with torn connecting rods and a hole in the block, in general, they killed as best they could, how I always felt sorry for them ...
By the way, I’m now observing such a trend in my area, the old YaMZ238 ​​engines began to be replaced with YaMZ240 decommissioned from storage in military units, which are recognized as obsolete in the armed forces and uncle generals sell new, factory-tested engines to carefree farmers or cunning dealers. Farmers, in turn, turn to me with a request to replace the piston rings, which have sat down for 20 years of inactivity, and also to change the seals, which have become stiff during this time. Also, our collective farmers realized that the Soviet Kirovians are much more suitable for our fields than any waltras, challengers, etc. They are less whimsical and much cheaper to repair.

The YaMZ-240 diesel engine has several modifications and is installed on mining dump trucks with a load capacity of 30-40 tons. These are Belazs of various modifications, working in the mining, oil industry, and specialized agricultural machinery.

Characteristics of the YaMZ 240 M 2 engine.
HP power kw. 360 "265".
Rotates at a frequency of 2100.
Torque, maximum 1275 Nm. 130 kgf-m.
Speed ​​at maximum kr./m. 1600.
Minimum fuel consumption 214 g/kW-h, 157 g/hp-h.
Number of cylinders 12.
The number of valves is 24. The order of operation is the first, fifth, third, sixth, second, fourth, seventh, eleventh. Ninth, twelfth, eighth, tenth.
The block material is cast iron.
Cylinder head, made of cast iron.
Cylinders arrangement V.
Piston stroke 140 mm.
The working volume is 22.3 liters.
Dimensions 1580*1015*1190 mm. Fuel pump. High Pressure. 90.8-20.
Generator 6301.3701.
Weight 1670 kg.
YaMZ-240-PM2 engine.
Power is 309 kW. or 420 hp
Rotates with a frequency of 2100 rpm.
Torque maximum 1491 N.-m, 152 kgf. - m.
Speed ​​at maximum torque 1600 rpm. Fuel minimum consumption. 211 g/kWh 155 g/hp-h
Cylinders 12.
V configuration.
Valves quantity 24 pcs.
Has a piston stroke of 140 mm. Cylinder diameter 130 mm.
Power supply for injection pump and LP fuel priming pump.
Cooling liquid.
The block material is cast iron.
Tact four-stroke. Mass kilogram 1790.
YaMZ 240 NM2.
Power is 368 kilowatts or 500 hp.
Rotates at a frequency of 2100.
Torque maximum 1815 H.-m. 185 kgc. - m.
Speed ​​at maximum torque 1600 rpm.
Fuel consumption, minimum 208 g/kW-h, 153 g/hp-h
V configuration.
The block material is cast iron.
Liquid cooling.
Tact four-stroke.
Power supply for HP fuel pump and LP fuel priming pump.
OHV valve mechanism.
Weight 1790 kilograms.

The Yamz-240 motor is the most powerful of all the engines produced by the Yaroslavl Motor Plant, this engine corresponds to EURO-0 in its technical parameters. It is a twelve-cylinder, four-stroke diesel engine. Liquid cooled, direct fuel injection and compression ignition.

Yamz-240 engines are distinguished by fairly quiet operation, the noise level they produce is 2-3 decibels, which complies with all international and, in particular, European norms and requirements and standards. This allows you to use this engine in a wide variety of conditions without discomfort to consumers. In terms of the emission of harmful substances, this engine is also at its best, the amount of exhaust gases emitted into the atmosphere is approximately 25% lower than that of diesel engines of the same power and class. In addition, this engine has great reliability, and is quite easy to repair and operate. These motors are one of the most reliable diesel engines in their segment.

The pride of Soviet industry, one of the symbols of its power, was the huge BelAZ mining dump truck. The "heart" of this heavy equipment is Yaroslavl - a 12-cylinder YaMZ-240 diesel engine. About the technical features of this model of the Yaroslavl Motor Plant and about where and how else the YaMZ-240 distinguished itself during its operation - later in this article.

YaMZ-240 became the first twelve-cylinder engine, the production of which was mastered in Yaroslavl. It was developed almost in parallel with the 6-cylinder and 8-cylinder, and was launched into the series shortly after them - in 1962. If the first two engines of this family were conceived and eventually became extremely versatile and multifunctional engines, then the YaMZ-240 was originally intended to solve a narrow range of special tasks.

These tasks are the equipment of specialized heavy equipment, the use of which implied the presence of a high power motor and, most importantly, powerful and constant traction. Namely, such equipment as mining dump trucks, snow and swamp vehicles, heavy tractors, diesel locomotives and special track machines.

Most of these powerful machines year after year toiled in a state of continuous endurance testing. Not only under loads close to extreme, but also in the harsh climatic conditions of Siberia and the Far North. As, for example, the ShSG-401 (Ermak) snow and swamp vehicle, designed to transport bulky goods weighing up to forty tons (drilling equipment parts, power transmission towers, containers, generators and pumping stations, pipes, building materials).

Snow and swamp chassis "ShSG-401", based on "Kirovets" with the engine "YaMZ-240"

Or the BelAZ quarry hero, designed to move large volumes of rocks from their place of extraction in difficult climatic areas. In the mining industry, in coal mines, in factories and process shops, as well as in the construction of large-scale production facilities.

The world-famous and no less legendary example of the Soviet industry than BelAZ was the Kirovets heavy tractor of the 5th traction class. YaMZ-240 was installed on its most powerful modifications - K-700A and K-701.

Diesel locomotive with YaMZ-240 engine

In the railway sector, YaMZ-240 was installed on MDP-4 diesel locomotives; on track "Smoothing-tamping-finishing machines of continuous action" - special trains intended for the construction, repair and maintenance of railway tracks.

Currently, the Yaroslavl Motor Plant produces six modifications of this family of 12-cylinder engines. Of these, 2 versions are “aspirated”, and 4 are gas turbine engines. The main demand in recent years is the YaMZ-240 / NM2 model, which is used on 42-ton heavy BelAZ dump trucks.

BelAZ-7523 dump truck with YaMZ-240/NM2 engine

• The base model of the family is now YaMZ-240/M2. These engines have replaced the YaMZ-240 / M engines produced before 1988 and are interchangeable with them. Their main purpose is to install several modifications (mainly BelAZ-75405) on BelAZ mining dump trucks with a payload capacity of up to 30 tons and a gross weight of up to 52 tons. Power - 360 horsepower.
• Engine YaMZ-240/BM2-4 is a tractor modification "YaMZ-240/M2". It is designed specifically for use on heavy tractors "Kirovets K-701". Currently, this model of the famous tractor has been discontinued (in 2002). Accordingly, YaMZ-240 / BM2-4 motors are not installed on new equipment and are supplied exclusively as spare parts. Since this version of the engine is produced without a fluid coupling, the generator, which is structurally installed on the fluid coupling, is also not supplied with the engine. YaMZ-240 / BM2-4 engines are interchangeable with YaMZ-240 / BM engines, which were made before December 1988, and with YaMZ-240 / B, produced before October 1985. The power of the "tractor version" is 300 horsepower.
• Option YaMZ-240/PM2- This is a turbocharged engine modification designed for BelAZ -7540A, -75401, -75406, -75409, with a load capacity of 32 tons and a gross weight of 53 tons. Technologically, this motor is similar to the YaMZ-240 / M2 engine, and differs from it only in the presence of a turbocharging system.
• Engines YaMZ-240/NM2 also belong to the class of forced turbocharged engines. They are installed on BelAZ-75485 mining dump trucks with a total operating weight of up to 72 tons. The power of YaMZ-240 / NM2 is 500 horsepower, against 420 for YaMZ-240 / PM2.
• turbocharged engine YaMZ-240/NM2-1 also has a capacity of 500 horsepower and is used as a power unit for BelAZ -75485, -75486 and -75487, with a carrying capacity of 42 to 45 tons.

• It is also possible to install engines of the series on these models of mining dump trucks. YaMZ-240/NM2-2, with technical characteristics similar to the YaMZ-240 / NM2-1, and slightly differing structurally from them.

The layout and arrangement of the YaMZ-240 engine

Some mistakenly believe that the YaMZ-240 is not a completely independent V12 model, but simply two “paired” six-cylinder YaMZ-236s. Of course, this is not true. This family appeared not only by adding four additional cylinders to an eight-cylinder engine, but also by changing the angle of their collapse; way of supporting the main journals of the crankshaft, and a number of other original design solutions. Due to the fact that the cylinders in this engine have a special arrangement, it was possible to achieve a significant reduction in the total mass of the power unit. .Details below.

The cylinders are located on the engine in two rows, in a common block with the upper part of the crankcase and are made at an angle of 75 degrees. The right row of cylinders is pushed forward relative to the left, with an offset of 35 millimeters. This is due to the fact that two connecting rods are installed on a single connecting rod journal of the crankshaft, separate for the right and left rows.

Cylinder heads "YaMZ-240"

The crankcase block is a hard casting made of gray low alloy cast iron, on which the cylinder liners, crankshaft, camshaft bushing and high pressure fuel pump are precisely worked out. Cylinder heads, depending on the YaMZ-240 modification, there are 12 of them individually for each cylinder, or 4 whole ones (three cylinders for each). Spring-loaded valves with rocker arms and nozzles are located in the cylinder heads.

The crankshaft of the YaMZ-240 engine is produced by hot stamping, with hardening of the necks with high-frequency currents. The crankshaft consists of seven main bearings and six connecting rod journals. A liquid vibration damper is installed at the front end of the crankshaft. The main bearings of the crankshaft are roller bearings. Axial fixation is provided by a thrust bearing with two bronze rings. The power take-off for the operation of additional equipment and units (fan, compressor, hydraulic pumps) is made from the front edge of the crankshaft

The flywheel is cast from gray cast iron. It is equipped with a ring gear for starting the motor with a starter. Bolted to the hub on the tapered shank of the crankshaft. The hub is pressed on the shank with a large interference, therefore, when repairing the engine, it is impossible to do without a special tool to remove it.

Connecting rod of steel shaped forging, with an I-section rod. A special channel runs along this rod, specially drilled to supply oil to the bearing located on the upper head of the connecting rod.

Pistons are cast from high-silicon aluminum alloy. On each of them - three compression and one oil scraper ring, with an expander. The compression rings have a trapezoidal section. The pistons of the turbocharged versions of the YaMZ-240 differ from the pistons of the "atmospheric" engines: they have an enlarged combustion chamber and a groove on the skirt for the oil cooling nozzle. But the cylinder liners of all modifications of the 12-cylinder YaMZ are interchangeable.

Gas distribution mechanism

The gas distribution mechanism is an overhead valve, with a lower camshaft. The camshaft is a stamped carbon steel part; its necks and cams are additionally hardened. The total number of cams on the camshaft is 24 (for intake and exhaust valves). On each of the cylinders - one inlet and one exhaust valve, made of heat-resistant steel. The valves are tightly seated with special springs, with locks of a special design. This lock contributes to the rotation of the valves, which has a positive effect on improving engine performance.

Lubrication system "YaMZ-240"

This engine has a mixed type lubrication system, with a "wet sump". Oil circulation in the lubrication system is provided by an oil pump. From the crankcase, oil under pressure is supplied to the filter, passes through it. Further, through special channels and highways, it rushes sequentially: to the internal cavity of the crankshaft; to the connecting rod bearings, axles and push rods; to rocker arm bearings; to the camshaft bearings; in the cavity of the high pressure fuel pump and the speed controller. The oil that has passed the specified path is drained back into the crankcase.

In addition, for the turbocharged versions of the YaMZ-240, a jet oil cooling system for the pistons during their operation is provided. The oil for this special additional piston cooling is supplied through a system of special lines and nozzles.

Power supply system "YaMZ-240"

The power supply system of the 12-cylinder "Yaroslavets" includes the following components and assemblies: a high-pressure fuel pump equipped with an all-mode speed controller and an injection advance clutch; two fuel booster pumps; low and high pressure fuel lines; coarse and fine fuel filters; nozzles.

The speed controller is a mechanism that, by changing the amount of fuel supply depending on the load, maintains the engine crankshaft speed set by the driver or machine operator. The fuel injection advance clutch changes the timing of the start of fuel delivery, optimizing it in accordance with the specific speed of the crankshaft.

The order of the power system is as follows. Fuel priming pumps pump fuel, passing through the coarse filter, from the tank, and drive it to the high pressure pump. At the inlet to the injection pump, the fuel passes through a fine filter. In accordance with the order of operation of the cylinders, the high-pressure fuel pump supplies fuel, through the high-pressure fuel lines, to the injectors, which inject it into the working cavities of the cylinders. Excess fuel, as well as the fuel that leaked through the nozzles during their operation, flows back into the fuel tank through special low-pressure lines.

Turbocharging on forced versions of YaMZ-240

Each of the turbocharged modifications of these engines is equipped with two K-36 turbochargers, which use the energy of exhaust gases for additional engine boost. Turbochargers significantly increase the mass of air that enters the cylinders. This contributes to a more complete and efficient combustion of increased doses of fuel. Due to this, the engine power indicators increase, while maintaining moderate thermal stress, and with lower fuel consumption.

It should be noted that in Soviet times, YaMZ-240 engines were equipped with K-36 turbochargers manufactured in Czechoslovakia. Since 2010, turbochargers of domestic production, NPO Turbotekhnika (Protvino, Moscow Region) have been installed on engines of this family. In their design, they are completely similar to the "K-36", but have a different name - "TKR-100".

Engine cooling system "YaMZ-240"

The engine cooling system is liquid, circulating. The centrifugal pump circulates the coolant. From it, under pressure, the liquid enters the water jackets of the left and right row of the cylinder block; after that - in the cylinder heads, and is collected in the catchment pipelines. Of these, the heated liquid is fed through thermostats to the radiator, where it gives off heat to the air flow from the fan and again enters the water centrifugal pump. If the temperature "outside" is low, then the thermostats supply coolant immediately to the centrifugal pump, bypassing the radiator.

YaMZ-240 is a 12-cylinder, four-stroke, compression-ignition diesel engine with a long piston stroke and high thrust. The arrangement of the cylinders is V-shaped, with a camber angle of 75 degrees. The power of the YaMZ-240 engines varies, depending on their modification, from three hundred to eight hundred horsepower.

"YAMZ-240 / BM2-4" - tractor modification, especially for "Kirovtsy"

First, about the technical parameters common to both atmospheric and gas turbine versions of the family:

• The working volume of the engine is 22.3 liters.
• Cylinder diameter -130 mm.
• The piston stroke is 140 mm.
• The torque range is from 1275 to 1818 rpm.
• The nominal speed of the crankshaft is 2100 rpm.
• The crankshaft speed at maximum torque is 1600 rpm.
• The minimum crankshaft speed is 60 (=/-50) rpm.
• The maximum crankshaft speed is 2325 rpm.
• Overall dimensions of the motor: Length from 1577 to 1860 mm; Width from 1014 to 1098 mm; Height 1190 mm.
• Lubrication system capacity - 39 liters; cooling systems - 35 l.

On the numerical expression of indicators that are different for atmospheric and turbocharged versions:

• Power - from 300 to 420 horsepower for aspirated; from 500 to 800 horsepower - for gas turbine modifications.
• Specific fuel consumption at rated power: 230 g/kWh for atmospherics; 224 g/kWh for NM gas turbine sets; 228 g / kWh for gas turbine series "PM".
• Unfilled engine weight: 1670 kg - non-turbo engine; 1790 kg - turbocharged "engine".
• The compression ratio in the naturally aspirated engine is 16.5; in the gas turbine - 15.2.

Operating experience of YaMZ-240 engines and owner reviews: advantages and disadvantages

The advantages of the YaMZ-240 engines, which are unanimously pointed out by all those who have experience in their operation, are excellent power and traction; as well as amazing unpretentiousness and durability. As for the first point, everything is clear here: the power taken from 12 cylinders (which work three at a time in a four-stroke engine) quite naturally gives an excellent result, and even with an “allowance”. Due to the solid power reserve, the load on the “vital” engine components is also reduced accordingly.

More specifically, about the durability of YaMZ-240: the engine has a really long service life, even under operating conditions that are unthinkable for imported diesel engines. As a rule, "YaMZ-240" does not bring trouble for the first 5-7 years of its "service"; the further fate of the motor depends on who and how works on this technique; Is she being properly cared for? Moreover, the word “care” means only the most elementary and simplest manipulations: timely replacement of oil and consumable filters; control that diesel fuel does not get into the oil, etc.

The reliability and unpretentiousness of the YaMZ-240 engines really inspire respect. There is no shortage of real life stories, when they drove equipment with YaMZ-240, if necessary, without oil, and without coolant, and with torn connecting rods, and with a hole in the block, with inverted liners ... But the motor endured and successfully experienced these terrible forced "experiments".

Among the shortcomings of these engines include a rather “intricate” engine lubrication system compared to other YaMZs. In particular: for example, the oil supply to the crankshaft occurs through a hole at its very beginning. And on the very last, sixth neck, lubricant is supplied through the entire crankshaft. If, for any reason, the oil pressure in the system decreases, then the lubricant simply stops reaching this last neck. The sixth neck begins to “starve” for oil, and if this is repeated systematically, then there is a real risk of the crankshaft knocking or jamming.

Another negative difference between YaMZ-240 and 6-cylinder YaMZ-236 and 8-cylinder YaMZ-238 is the complexity of its repair. For example, removing the rear flange of the crankshaft to which the flywheel is attached is tantamount to a feat. However, an even greater feat is to “put” him back, in place to the end. The mechanics of Kirovets K-701 point out that without special skills and experience acquired during the relevant training, even a simple repair of a 12-cylinder Yaroslavl is not possible.

Not only A. Lukashenko, but also D. Medvedev tried himself as a “driver of BelAZ”.

Another controversial issue is fuel consumption. Of course, such a "monster" as YaMZ-240 is very voracious, even compared to its "younger brother" - YaMZ-238. However, the peasants unequivocally point to the disproportionately higher productivity of the K-701 compared to other tractors, including the K-700. The 701st "Kirovets" plows much more confidently and faster, and on the basis of this, many prove the opposite: the increased fuel consumption is compensated by greater productivity and, as a result, it turns out to be economically even more justified. So there is no single point of view on this matter.

Price for YaMZ-240 engines

Prices for new YaMZ-240 engines in the official price list of the Yaroslavl Motor Engine start from 700,000 rubles for atmospheric engines and from 800,000 rubles for gas turbine versions. In addition, there is no shortage of offers on the Internet to purchase remanufactured YaMZ-240 engines, as well as those reactivated from long-term storage in the state reserve and in military units, at a price of 1.5-2 and even 3 times cheaper than a new one.

Diesel engines for trucks and tractors. Spare parts, adjustments and repairs.

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Diesel engine YaMZ-240

Diesel YaMZ-240 (modifications NM-2, M2, BM-2, PM-2) - twelve-cylinder, naturally aspirated, liquid-cooled with automatic thermal control, develops an operating power of 198 kW, a rated speed of 1900 min-1 and a maximum torque 1240 Nm.

The main parts of the YaMZ-240 diesel engine: body, crank and gas distribution mechanisms.

Frame

The body of the YaMZ-240 diesel engine (modifications NM-2, M2, BM-2, PM-2) consists of a crankcase, four cylinder heads and their four covers, the front cover of the block, end sheet, flywheel housing and drive units, pallet.

The crankcase is of a tunnel type, with a V-shaped arrangement of cylinders at a camber angle of 75°. In its partitions there are seven supports for the axes of the pushers, crankshaft and camshaft, and in the crankcase itself there are twelve bores for cylinder liners.

The cylinder block is assigned to the tunnel type because the supports in the transverse partitions are made in one piece, the outer rings of the roller bearings are pressed into the bores of the lower supports.
bearings, and the crankshaft is installed in the crankcase in series, bypassing one support after another, that is, as if moving through the tunnel.

In the collapse of the crankcase there are lugs with holes for fixing the high-pressure fuel pump and a breather for connecting the oil supply pipes to the pneumatic compressor and draining the drain fuel into the tank.

On the left side surface of the cylinder block of the YaMZ-240 engine, flanges and bosses are made with holes for installing and connecting an oil pump,
a pipe for draining oil from the fluid coupling housing of the fan drive, pipes for supplying coolant to the pneumatic compressor and draining it from the heating boiler, as well as a pipe for the water pump.

On the right side surface of it, flanges and beds are provided for a coarse oil filter, a starter and a housing with an oil measuring rod.

At the front end of the crankcase there is a cover, centrifugal oil filters
and rough fuel cleaning, as well as the housing-bracket of the hydraulic coupling of the fan drive, which simultaneously serves as the basis for mounting the generator and compressor.

An end sheet and a flywheel housing are attached to the rear end of the crankcase, four cylinder heads are attached to its upper part, and a pallet is attached to its lower part.

The cylinder head of the YaMZ-240 diesel engine (modifications NM-2, M2, BM-2, PM-2) is group, common for three cylinders. The cylinder heads are interchangeable, they are mounted on studs screwed into the crankcase and fastened with nuts.

The joint between the crankcase and cylinder heads is sealed with a steel-asbestos gasket. Carefully machined valve seats made of special cast iron and valve guides made of powdered materials are pressed into the cylinder head seats.

Valves with springs, rocker arms, rocker arms, injectors are attached to the cylinder heads inside; outside on the side surfaces - an exhaust manifold (opposite the collapse), a water pipe and an intake manifold (from the collapse side), and on the end surface - an eyebolt. The cavity of the cylinder head is closed with a cover, the joint is sealed with a rubber gasket.

In the front cover of the crankcase there is a torsional vibration damper, a bearing device for driving the drive pulley of the V-belt drive and two fuel priming pumps.

On the right side surface of the cover there is a hatch for access to the dial on the vibration damper housing and for setting the crank mechanism to the required positions when adjusting the fuel injection advance angle and
thermal gaps in the valves of the gas distribution mechanism.

A traverse is put on the trunnion of the front cover, designed for installation
frame engine.

In the crankcase of the flywheel of the YaMZ-240 diesel engine there is a crankshaft shank on which a flywheel with a crown is installed, and gas distribution mechanism drives,
high pressure fuel pump, water and oil pumps, manual crankshaft cranking mechanism.

There is a bore on the crankcase for fixing the starter in it; studs for mounting the rear engine mounting brackets to the frame and two manhole covers.

Since access to the hatch covers of the flywheel crankcase is difficult, therefore, when adjusting the thermal gaps in the gas distribution mechanism and the fuel injection advance angle, the graduations printed on the torsional vibration damper are used.

On the end surface of the flywheel housing there are holes for mounting the pump drive gearbox.

Two baffles are made in the body pan to increase its rigidity and prevent oil from splashing out during movement; threaded holes (one at the bottom for draining the oil, and the other at the back for installing an oil temperature sensor) and 40 holes for attaching the sump to the crankcase.

Chassis Maintenance

During shift maintenance (ETO), in the process of external inspection, they reveal: whether oil, coolant and fuel are leaking; whether gases make their way through the joints of the sump and cylinder heads with the crankcase.

During the first maintenance (TO-1) YaMZ-240 (modifications NM-2, M2, BM-2, PM-2), the tightening of the nuts and bolts of the assembly units is checked.

After one TO-2 (after 480 m / h), using a torque wrench, the tightening of the cylinder head nuts is controlled. Nuts are tightened in several stages by no more than 1-2 faces
in the sequence shown in figure 3.

If necessary, but at least after 2000 hours, the cylinder heads are removed for cleaning from carbon deposits and lapping the valves.

Removing the cylinder head is done in the following sequence:

Open and fix the cover of the hood lining.

Unscrew the filler caps of the cooling system. Open the valves on the diesel water pipe and on the heating boiler, drain the coolant.

Remove the breather covers (the breather is located in the collapse of the crankcase), unscrew the plug from the sump and drain the oil from the lubrication system.

Remove the cylinder head cover, and then the high and low pressure pipelines connecting the high pressure fuel pump to the injectors and the injectors to the right fuel tank (or tank), respectively. The fuel line openings are wrapped with clean rags and bandaged (or covered with insulating tape).

Mounting brackets and nozzles are removed from the YaMZ-240 diesel engine.

Disconnect the exhaust manifold from the cylinder head and remove it.

Disconnect the oil lines from the hydraulic clutch switch (located on the right front head) and remove the water pipe.

Disconnect the fuel lines and remove the fine filter.

The intake manifold is disconnected from the air purification system, and the radiator coupler is disconnected from the (front) cylinder heads.

Having unscrewed the nuts securing the rocker axles, remove them together with the rocker arms and remove the rods.

Having unscrewed the fastening nuts, remove the cylinder head and close the cylinder holes with special covers or paronite sheets to prevent dust and dirt from entering them.

Hull repair

In the process of operation, malfunctions of the case may occur, the elimination of which is associated with its disassembly.

Cracks in cast iron parts (crankcase, cylinder head, exhaust manifolds) are cut at an angle of 60, drilled at the ends and welded with a Ts4-A or 0.34-11 electrode.

When welding with the Ts4-A electrode (diameter 3 mm), the current is direct, direct polarity or alternating with a force of 60-90 A. When welding with an electrode 034-11 (diameter 3 mm), the current is direct, reverse polarity, with a force of 90-120 A. The length of the weld should be 30-50 mm.

With a wall thickness of more than 6 mm, a multilayer seam is applied. After applying each seam, the deposited layer is forged to relieve internal stresses and reduce the porosity of the material, and then the welding spots are cooled to 100C.

To ensure tightness, the seam is soldered with soft solder or impregnated with epoxy glue or a composition based on epoxy resin ED-6.

To prepare an epoxy composition, ED-6 resin is heated to a temperature of 323-353K (50-80C), dibutyl phthalate is added and thoroughly mixed for 10-15 minutes.

After cooling to 288-298 K (15-25C), polyethylene-polyamine is introduced into the mixture and stirred for 5-6 minutes until a homogeneous creamy mass is obtained. In this case, a significant amount of heat is released.

Then fillers are introduced in the form of powders and again thoroughly mixed until a homogeneous composition is obtained. Before applying the composition, the weld is degreased with acetone or gasoline.

Removing the pallet

The pallet is removed in the following sequence:

Drain the coolant from the cooling system and the oil from the lubrication system.

The electrical wires are disconnected from the clamps on the blower motor.

Having unscrewed the union nut, disconnect the fuel line from the valve on the frame.

After loosening the tension of the tapes, remove the hoses from the outlet pipes.

They bring a trolley with a mobile platform and raise the latter to the stop.

Having unscrewed four bolts from the extreme holes in the frame, the platform is lowered and the trolley is taken out.

Remove the oil level indicator from the crankcase and unscrew the bolts. Then the tray is removed.

Of the entire line of engines that the Yaroslavl Motor Plant produces, the 240 is distinguished by the highest performance and the greatest demand. Such power units are equipped with tractors, excavators, trucks, tractors. They are installed on special equipment that is used in municipal utilities of cities.

In addition to performance, design solutions provide a low noise level of the unit, which makes it possible to comfortably use machines in residential areas. Different versions of the motor have individual technical characteristics. This makes it possible to choose a complete set exactly for the parameters of the machine.

1 YaMZ 240 engine design

The production of the YaMZ 240 engine began back in the 70s. It was the first 12-cylinder engine of the enterprise. The initial purpose of the unit was installation on heavy equipment of various types.

On the basis of such an engine, the productive BelAZ (240nm2) and heavy tractors Kirotsvets K-700A and Kirovets-K701 worked. Accordingly, the main quality of such a device should have been power. It is on her that the entire design of the unit is oriented.

This engine model consists of the following functional blocks:

• cylinder block;
• crank mechanism;
• oil supply line;
• engine cooling mechanism;
• gas distribution mechanism;
• device power system.

1.1 The design and placement of the cylinders of the unit

The cylinder block is located in the upper part of the cast housing, in the same place where the upper part of the crankcase is located. YaMZ 240 uses 12 cylinders. They are arranged in two rows of 6 pieces with convergence at the bottom. The angle of inclination of the cylinders relative to the central axis is 75 degrees. The right row relative to the left is shifted by 35 mm.

The block crankcase is made of gray reinforced cast iron and is a cast structure. In its upper part there are holes for each sleeve. The crankshaft, high pressure fuel pump (high pressure fuel pump) and the camshaft bushing are also located here.

Cylinder heads are arranged individually, depending on the modification, or in blocks, each of which is designed for three cylinders. Injectors and a valve are mounted in the upper part of each head.

1.2 The device of the crank mechanism

The crank mechanism installed in is a crankshaft, flywheel and bearings. The crankshaft is made of steel. The design includes six necks and seven round supports. The shaft journals are also made of steel, but during the manufacturing process they are reinforced by electric current treatment.

The shaft is mounted in the crankcase using a thrust bearing. The bearing is supplemented with bronze rings, which play the role of seals and enhance the fixation of the crankshaft. All units and equipment of machinery take power from the shaft through the front edge. There is also a mechanism responsible for damping vibrations. The absorber operates on the basis of a viscous liquid. It consists of a cast body, flywheel, fluid inlet and protective cover. Centering on the axis is carried out by a separate metal plate.

A hub with a shank is placed on the opposite end of the shaft. This shank has a cast iron flywheel. Steel rods are attached to the shaft. They are mounted on a steel rod. A channel is drilled along the entire length of the rod, which supplies oil to the rubbing mechanisms.

Pistons are installed on the connecting rods. They are made from an alloy of aluminum and silicon. Four metal rings are mounted around the circumference of the sleeve. Three of them are responsible for housing compression, one is oil scraper.

1.3 Structure of the oil supply mechanism

The lubrication mechanism installed on this diesel engine is used to prevent wear of moving parts and bearings. Also, with its help, parts are cooled, spent particles are removed.

The oil system starts working as soon as the diesel is turned on. Lubricant is taken from the sump using an oil pump. The pump creates high pressure at the outlet, due to which the oil rushes further to the fine filter. From here the pipeline is divided into several lines. One of them directs the lubricant to the moving parts of the crankshaft, and then through the appropriate channel to the connecting rod bearings. After that, the liquid passes to the fingers of the cylinders and to the connecting rod bushings.

The second line supplies oil to the pushers and to the YaMZ 240 centrifugal oil filter. Then, using this line, the camshaft bearings are lubricated. Parallel to it is a channel that supplies lubricant to the radiator from the oil pump. Oil is supplied to the cooling fan drive and compressor through external tubes, which also come out of the fine filter.

Getting into the crank mechanism and the cylinder block, the oil is sprayed and forced through the gaps of the parts. Due to this, the nodes are lubricated. Further, the lubricant flows down the surfaces of the nodes into the sump and the cycle repeats.

1.4 Cooling system

The cooling mechanism installed on the YaMZ 240 diesel engine is a closed-type circulation system. The mechanism works based on the movement of the coolant. This scheme consists of the following nodes:

The centrifugal pump draws liquid through a recess between the roller and the sleeve. The device turns on after the accumulation of a sufficient amount of liquid in the working chamber. The pumping device is driven by a gear connected to the crankshaft.

The liquid is cooled in the radiator, thanks to the air flows created by the fan (also driven by the crankshaft). From the radiator, the liquid enters the shirts, where it is evenly distributed. After cooling, hot water is discharged through pipes at the top of the heads. A spare part such as a thermostat is mounted in the pipeline, with the help of which the valves are adjusted.

Steam accumulating in the line is discharged through an opening in the expansion tank.

1.5 Gas distribution design

The gas distribution system is used to supply air into the working chambers of the motor and timely discharge of exhaust gas mixtures. It consists of a camshaft, cylinders, intake and exhaust valves. The camshaft of the mechanism is located at the bottom of the block. It provides the movement of the valves inside the cylinder. The camshaft consists of 24 cams and necks connecting them. Both cams and necks are made of carbon steel. At the same time, during stamping, the shaft is additionally hardened.

The cylinders of the mechanism are made of reinforced steel, which is designed for high temperatures. Valves are located in the upper part of their bodies. They are planted on special springs that tightly press the valve to the seat. Each individual cylinder has two valves (one for intake, one for exhaust). The design also includes a lock that provides a slight scrolling of the valve, which implements less wear on the part and prevents frequent engine repairs.

1.6 Fuel feed mechanism

The power line of a 12-cylinder diesel engine is responsible for supplying fuel into the combustion chambers of the piston. The mechanism includes:

• high pressure fuel pump (TNVD);
• two booster pumps;
• fuel supply line (pipeline);
• nozzles;
• impurity filters.

Also included is a special speed controller. This adjusting assembly is designed to maintain a stable supply of fuel to the combustion chamber, to the extent that it will provide a given rate of rotation of the crankshaft of the device.

The description of the principle of operation of the power supply circuit of the motor includes the following steps:

• booster pumps take the diesel from the tank through the filters and transport it under pressure to the injection pump;
• The high-pressure fuel pump delivers the mixture to the cylinders through pipe sections, in the order that is laid down in production;
• All diesel that did not enter the combustion chamber, but went beyond the working units, flows into the tank through additional channels.

2 Model performance

This version of the diesel engine includes a number of configurations, each of which has individual indicators of individual performance characteristics.

These modifications include YaMZ 240b, used for tractors, as well as 240NM2 and 240PM2, which belong to turbocharged models. And, anyway, most of the technical characteristics of the units have similar meanings:

• motor power is up to 400 hp. With. in models operating in atmospheric air, up to 800 liters. With. in models with turbocharging;
• the volume of the internal part of the motor - 22.3 l;
• the piston during operation is displaced vertically by 140 mm;
• the working value of the crankshaft speed reaches 1600 rpm;
• the maximum rotation of the crankshaft per minute is 2300 rpm;
• the volume of the oil supply mechanism - 39l;
• the cooling mechanism holds 25 liters of liquid;

As for the dimensions, the length of the device, depending on the modification, is 1570-1860 mm, the width of the unit reaches 1098 mm, the height is 1200 mm. At the same time, the weight of standard modifications does not exceed 1670 kg. Turbine versions weigh up to 1800 kg. Fuel consumption for all engine configurations averages 230 g / kWh.

2.1 Starting the YaMZ 240 engine after overhaul (video)