"D-120" is a two-cylinder, four-stroke diesel engine with direct injection of diesel fuel and air cooling, manufactured by the Vladimir Motor-Tractor Plant. These power units are known, first of all, as motors of self-propelled chassis "SSh-2540" ("T-16", "T-16M"), as well as tractors "Vladimir" "T-25", "T-28", " T-30 "," KhTZ-2511 ".

In addition to these tractors, the D-12O engines in Soviet times were widely used on small-sized loaders (PUM-500, PUM-500M, DP-1604), welding units of the ADD type, at power plants (AD-8-T400-1VP , ED-8-T400-1VP), compressor stations "PKSD-1.75", etc. The motors have passed a solid test of time, over many decades, and have established themselves as unpretentious and reliable, easy to operate and maintain, quite economical diesel engines.

Earlier, power units of modifications "D-12O-44" and "D-12O-45" were produced in Vladimir under the names "D-21" and "D-21A-1". From these. earlier models "D-12O-44" and "-45" are distinguished by a higher crankshaft speed and increased power.

The Vladimir Motor-Tractor Plant is practically the same age as the Great Victory: its first stage was built in 1944 and commissioned at the end of April 1945. At the same time, the Vladimir Tractor Technical School (now a Polytechnic College) was opened to train specialists. The plant produced compact wheeled tractors, the most famous of which were the tractors "Vladimir" -, "T-25A", "T-28", "T-30".

Since the 50s, the production of diesel engines has been mastered here, work has been done to improve their design. In 1962, for the first time in the domestic machine building, four-cylinder D-37M diesel engines were put into serial production here.

During the Soviet era, tractors and diesel engines from Vladimir were exported to more than sixty countries of the world (the share of exports reached 40% of the total). in 1988 the plant produced its four millionth engine and one millionth tractor. The branches of the enterprise were two aggregate plants, a mechanical assembly plant and a plant for special tools and technological equipment located in the city and the region.

Tractor "Vladimir T-25".

In the post-perestroika era, the Vladimir Motor-Tractor Plant continued, with varying success, to stay afloat until the 2010s. Here, in 1998, they launched the production of an updated "top-top" - a self-propelled chassis (in Soviet times, the "top-top" "T-16" was produced in Kharkov). In 2005, the thousandth such car was produced. In the late 90s / early 2000s, the production of new tractor models with modern design and improved technical characteristics was launched: VTZ-2000 (VTZ-2O27, VTZ-2O32); "T-45", specially adapted for work in greenhouses; VTZ-2O63AS "Turbo-99" (60 hp); 80-strong tractor "VTZ-2O8OAS" Vityaz-2OOO "; fork loader "VTZ-3OSSH-PV"; "T-5O" (), "T-85" (class 1.4); communal car "VTZ-3OSSH-K0". The production of engines did not stand still: along with air-cooled diesel engines, liquid-cooled motors, as well as economical methane engines, were developed and introduced into production. However, all these products, by and large, have not found their buyer in a market economy.

In the fall of 2017, the assets of the Tractor Plants concern, which included VMTZ, were transferred to the state corporation Rostec, which, together with a number of ministries, took up the “rehabilitation” of these enterprises, which had been in a state of long-term crisis. The last employees of the plant - more than three hundred people were formally employed by transferring to the Cheboksary "Promtractor" and brought to idle time, receiving from 5 to 7 thousand a month. On July 20, 2018, all of them were laid off for layoffs, and the VMTZ enterprise was liquidated. The Vladimir Motor-Tractor Plant has joined a huge list of thousands of large enterprises of the Soviet period that ceased to exist in the 2000s.

Design features of the D-120 engine

The main feature of this engine is, of course, the air cooling system. It greatly simplifies its maintenance and operation. There is no need to install a radiator, expansion tank and other elements that are indispensable for a liquid cooling system.

The engine is compact in size and relatively small, especially for diesel engines, in weight. Also in the design of the D-120 diesel engine, an original balancing mechanism was used. It negates the vibration inherent in all two-cylinder engines. Specific fuel consumption is at the level of the best economic indicators for diesel engines, and the optimal layout on the equipment that "got" this engine makes maintenance and repairs as convenient and affordable as possible.

Depending on the applicability and characteristics of a particular purpose, diesel engines "D-12O" were produced in complete sets with a nominal crankshaft speed of 2000, 1800 or 1500 rpm. In particular, in addition to the basic tractor configuration, these are:

Diesel "D120" consists of the following components: a crank mechanism, a balancing mechanism and a gas distribution mechanism, a decompressor, a power supply system, lubrication and cooling, electrical equipment.

The main part of the motor is the crankcase. In the bores of the crankcase, two cylinders are placed vertically, in a row, which are sealed with gaskets in the lower part. At the rear end of the crankcase there is a flywheel housing, which connects the power unit to the gearbox. At the front end of the engine there is a front sheet, with a fuel pump and a distribution gear cover installed on it. The lower part of the diesel engine crankcase is covered with an oil pan.

The crank mechanism creates the rotation of the crankshaft, using the gas distribution system, while converting the movements of the pistons into energy. The engine crankshaft speed controller is centrifugal, all-mode with a fuel supply corrector. When the engine is running, the pistons are affected by the pressure of gases converted from the combustion of diesel fuel. Through the connecting rod, the force is transmitted to the crankshaft, which rotates from these forces. The flywheel reduces the imbalance of the diesel engine and transfers the torque through the clutch to the tractor transmission.

In the axial direction, the crankshaft is fixed with half rings, which are installed in the bores of the middle crankcase partition and in the main bearing caps. Three compression rings are installed on the pistons. The oil scraper ring on the piston is one, combined. The combustion chamber is located in the piston crown. The balancing mechanism equalizes the moment from the inertial forces when the diesel engine is running. This mechanism consists of an additional roller with counterbalance weights and special lugs on the front pulley and diesel flywheel.

The roller rotates at the same speed as the crankshaft, but in the opposite direction. The drive is carried out from the leading timing gear through the intermediate and driven gears. The operation of the gas distribution mechanism must be synchronous with the supply of diesel fuel, and the gears are installed strictly according to the marks on the gears.

A decompressor is needed for easy starting of the diesel engine. In addition, an emergency decompressor is used to stop the motor. The decompressor consists of a rack, of two rollers and two levers, which are pivotally connected to the rack. The levers are rigidly connected to the rollers, and their ends enter the intake valve lifters. Moving the rack turns the levers with the rollers, and the pushers rise, which slightly open the intake valves using the rods and rocker arms. In the off state, the pushers do not lift the rollers.

The method of mixture formation is an undivided combustion chamber (a chamber in the piston) with direct injection of diesel fuel. The nozzles on the "D-12O" are installed of a closed type, with a multi-jet spray. Brand - "16.1112010", pinless. Coarse filter for diesel fuel - mesh, with replaceable filter cartridge. Fine filter - with replaceable filter paper element. Air purifier - oil inertial.

The lubrication system of the D-12O diesel engine is combined: under pressure from an oil pump and spray, with further cooling, in an oil cooler. The oil pump is mounted on a gear, driven by the engine crankshaft. For lubrication, motor oils "M-10G-2" and "M-10-B2" are used - in the summer, "M-8G2" and "M8-B2" - in the winter.

The cooling system of this engine is air, forced, with a guide vane, which is installed in the inlet of the cooling air flow; with an axial fan driven by a belt drive. Regulation of the thermal state of the diesel engine is forced, seasonal, by turning on / off the oil cooler, as well as by means of the fan throttle disk, which is installed in front of the guide vanes. The thermal state is monitored using a warning lamp, and there is an indicator of the oil temperature in the lubrication system.

The fuel pump is installed single-plunger distribution type "5Z.11.11.ОО4", or two-plunger type "2UTNM". The D-120 diesel engine is equipped with an SCH-102V hour meter.

Updated "top-top": self-propelled chassis "VTZ-3OSH", with the "D-120" engine, produced since 1998.

• Operating power: 15.4 kW (21 HP), or 18.4 kW (25 HP), or 22 kW (30 HP), depending on the version.
• The rated speed is 1500… 1800… 2000 rpm, respectively.
• Specific fuel consumption at rated power is 241 g / kWh (177 g / hp h).
• Maximum torque - 103 N.m (10.5 kgf.m), or 104 N.m (10.6 kgf.m), or 113.4 N.m (11.55 kgf.m), depending on modifications.
• Rated safety factor of torque - 15 (-3, +10).
• The order of operation of the cylinders is 1-2-0-0.
• The cylinder diameter is 105 mm.
• The piston stroke is 120 mm.
• The working volume of the cylinder is 2.08 liters.
• The compression ratio is 16.5.
• Estimated valve timing: start of intake - 16 degrees to TDC; inlet end - 40 degrees after BDC; beginning of release - 40 degrees after BDC; end of release - 16 degrees after TDC.
• Relative oil consumption for waste is 0.3-0.5% of diesel fuel consumption.
• Overall dimensions: length - 689 mm, width - 628 mm, height - 865 mm.
• Engine weight (unfilled, as delivered) - from 272 to 295 kg, depending on the configuration.

On the secondary market, there are a number of offers for the sale of both unused and used ones, or diesel engines "D-120" restored after overhaul. The price for them varies from 60,000 to 130,000 rubles.

For many decades, the Volvo Group's strategy has been to create quality competitive cars. The latest innovative developments are used to create new models of power units, one of them is the Volvo D12S.

Features of the power unit Volvo D12S
The engine of this model, used to complete the VOLVO FM12 and FH12 trucks, has a volume of 12.1 liters. Depending on the modification, it can have a capacity of 340 (D12C340), 380 (D12C380), 420 (D12C420) or 460 (D12C460) l / s. It has several advantages such as:

10 percent more torque than the D12A powertrain it was based on. The crankshaft speed ranges from 1100 to 1700 rpm.
- Optimization of the geometry of the fuel combustion chamber.
- Equipping the power unit with a pre-heater.
- Realization of precise injection thanks to the EMS engine management system.
- Expansion of the maximum torque zone by optimizing the valve timing.
- Equipped with an integrated brake compression mechanism.
Models of the Volvo D12S engine, produced in the period from 1998 to 2005, are equipped with a system that must cool the forced air, as well as pump nozzles equipped with electronic control. Structurally, the pistons can be manufactured in two versions:

Articulated 2-element. The upper part of the product is made of high-strength steel and the lower part is made of aluminum.
- Solid. The material for its manufacture is aluminum.
Two types of pistons are oil cooled. The oil is sprayed with a nozzle. These power units are very powerful and very economical.

The best offers from "AVMEX MOTORS"
If your vehicle is in an enforced downtime due to an engine that has failed, you can contact the Avmex-Motors company. One of our activities is the supply of contract engines from Western Europe, where we purchase components and assemblies at the largest auto dismantlers.

Starting from this stage, our specialists carefully check the quality of power units. After the cargo arrives at the company's warehouse, the mechanics at the stands once again carry out the entrance control. By contacting us, you are guaranteed to receive an engine that is in excellent condition, with a significant motor resource at an affordable cost.

About the oil consumption of the V-2 diesel engine and its numerous descendants (V-6 / V-6A / V-6B, V-46, A-650G, A-401, V-54T / A-712) installed on equipment as military (BTR-50, PT-76, T-72, ZSU Shilka), as well as economic (GT-T, ATC-59G, Vityaz DT-30, etc.), and how to fence it is written in note.

When you stand near a T-34 tank, wherever and in whatever condition it is, shiny with paint or, like ours, shabby and cut with a cutter, you want to take off your cap. Looking inside, in my thoughts I see my grandfather Misha, a radio operator gunner. I remember his story, how I crawled out of the car, engulfed in tongues of flame, near Vienna. This is the history of my people, the pride of my country. And the technical idea is still alive.

Technical thoughts led me with my GT-T to him, namely to his V-2-34 engine. More precisely, this is a SU-100 self-propelled gun, judging by the shape of the remains of the hull cut off during the conversion of a combat vehicle into a transport top.

Diesel engines of the B-2 type developed in the 30s are still characterized by high specific parameters, their specific gravity is only 2.05 kg / hp, and the specific fuel consumption is 165 g / hp * h. But the age of the design causes disadvantages, the main of which are: ineffective operation of oil scraper rings of an outdated design and, as a consequence, high oil consumption for waste - 20 g / hp * h; rapid wear of the valve guides and even greater oil consumption that enters the cylinders after lubricating the cylinder head camshafts.

The design of the GT-T transporter-tractor uses the power plant of the PT-76 amphibious tank based on single-row diesel engines of the V-6 family, derived from the two-row V-2.

Many parts and assemblies of this type of motors are unified. Including the head of the main (left) cylinder block assembly, blocks with liners (silumin and cast iron) and pistons. On my B-6A, the wear of the valve bushings for 33 years of moderate operation has developed so much that when the manifold is removed, the process of flight and combustion of oil is observed in the valves with the naked eye. I had to change the cylinder head assembly.

The emergence of new materials and technologies makes it relatively easy to eliminate the above disadvantages. Nevertheless, for many years of serial production of diesel engines V-2, D12, A-650 and M-401, their design has practically not changed. And in the engine compartments of modern Ural tanks, the original forms of the V-2 tank diesel are easily guessed.

In the late thirties, we created a unique tank engine that stepped into the 21st century. To understand what we are dealing with and to admire the design thought again, let's look into history.

At the beginning of the 30s of the twentieth century, special tank engines were not available not only for us. Thoughts that we were the first to put diesel on tanks are not entirely correct. The first to use a diesel engine on serial tanks in 1932 were the Poles, followed by the Japanese. These were low-power automobile diesel engines. The tanks were also relatively light. In the first half of the 30s. Soviet tanks were equipped with aviation gasoline engines that had exhausted their flight life. The operating conditions of a tank engine are sharp changes in the operating mode, load drops, difficult cooling conditions, air intake, etc. A tank engine must be more powerful than a car engine. Medium tanks needed an easy-to-operate, durable and reliable engine with a capacity of 300-400 hp, with good adaptability to significant overloads. As the German general G. Guderian wrote after the war, a tank engine should be considered the same weapon as a cannon.

In the early 30s, against the background of the lack of special tank engines in the world in general, in our country they began to create a special tank diesel engine. It was a daring undertaking. The best design personnel were thrown into its implementation. Despite the lack of experience, the designers began work on creating a diesel engine capable of developing crankshaft revolutions up to 2000 rpm. They decided to design it as universal, i.e. suitable for installation on tanks, aircraft and tracked tractors. It was necessary to obtain the following indicators: power - 400-500 hp. at 1700/1800 rpm, specific gravity no more than 0.6 kgf / hp. In the 30s, they worked on diesel engines not only at the NAMI Automobile Institute, but also at the Central Institute of Aviation Motors. They were developed for installation on airplanes and airships. The AN-1 heavy fuel aircraft engine created by CIAM was distinguished by its high efficiency and served as the basis for a number of many high-speed engines that are still used today, the basis and not a prototype, including the future tank engine.

By May 1, 1933, the high-speed diesel engine BD-2 was assembled and tested. But tests revealed so many defects in it that it was out of the question to put it on a tank. For example, the engine head with two valves did not provide the target power due to the low cylinder fill ratio. The exhaust was so smoky and pungent that it interfered with the work of the crews of the experienced BT-5 tanks. The crankcase and crankshaft structures were not sufficiently rigid. And nevertheless, by the end of 1937, a new finished model of a four-valve diesel engine was installed on the test bench, which by that time had received the name V-2. In the summer of 1939, the first B-2 serial diesel engines installed on tanks, artillery tractors and on test benches were subjected to the most rigorous examination.

In 1939, large-scale production of the world's first 500-horsepower high-speed tank V-2 diesel engines began, which were put into production by the same order of the Defense Committee, which adopted the T-34 and KV. The engine was born together with the tank.It had no analogues in the world of tank building. possessed amazing universalism.

Before the start of the Great Patriotic War, V-2 tank diesels were produced only by plant # 75 in Kharkov. The pre-war developments of the factory # 75 design bureau include the creation of a 6-cylinder tank diesel engine V-4 with a capacity of 300 hp. at 1800 rpm, designed for installation in a light tank T-50. Their production was to be organized at one plant near Moscow. The war prevented this. But factory # 75 managed to produce several dozen of these motors. Other pre-war developments - diesel engines V-5 and V-6 (supercharged), created in "metal". Experimental diesel engines were also manufactured: boosted in terms of speed up to 700 hp. V-2sf and 850-strong V-2sn supercharged. The outbreak of war forced to stop this work and focus on improving the main diesel engine V-2. With the beginning of the war, V-2 began to produce STZ, and a little later, plant No. 76 in Sverdlovsk and Chelyabinsk Kirovsky (ChKZ). The first diesel engines in Chelyabinsk began to be produced in December 1941. I. Ya. Trashutin (all engines of post-war Ural tanks) became the chief designer of ChKZ for diesel engines. But there weren't enough motors. And in 1942 a diesel plant No. 77 was urgently built in Barnaul (the first ten diesels were produced in November 1942). All in all, these factories in 1942 produced 17211, in 1943 - 22974 and in 1944 - 28136 diesel engines. T-34 tanks and self-propelled units based on it were equipped with a V-2-34 diesel engine (on BT tanks - a V-2 diesel engine, and on heavy KB there was its 640-strong version of the V-2K). It is a 4-stroke, 12-cylinder V-type high-speed naturally aspirated water-cooled diesel engine with fuel spray. The cylinders are angled 60 ″ to each other. Rated engine power 450 HP at 1750 rpm of the crankshaft. Operating power at 1700 rpm - 500 HP The number of revolutions of the crankshaft at idle speed is 600 rpm. Specific fuel consumption - 160-170 g / hp. The diameter of the cylinders is 150 mm, the displacement is 38.8 liters, the compression ratio is 14-15. The dry weight of the engine is 874 kg.

In the post-war years, the following modifications of the V-2 and V-6 engines were applied at the objects of armored vehicles: V-55, V-55V, V-54B, V-54, V-54G, V-54K-IS, V-54K-IST , V-105B, V-105V, V-34-M11, V-2-34KR, V-2-34T, V12-5B, V-12-6V, V-6B, V-6, V-6PG, V -6PV, V-6PVG, V-6M, V-6R, V-6R-1 and V-6M-1. The B-2 was also adapted for the most varied needs of the national economy with the birth of a large number of modifications. The V-404C engine for the Antarctic snowmobile "Kharkovchanka" became a great success of the designer.

In the 1960s, the Trashutin Design Bureau created the V-46 turbo-piston diesel engines for the T-72 tanks and subsequent generations of combat vehicles. Further development was the latest modifications of the B-82 and B-92, which at the turn of the century reached the parameters initiated by the designers of the B-2 in the 30s - specific weight 1 - 0.7 kg / hp, power more than 1000 hp. at 2000 rpm. Equipped with gas turbine supercharging, improved fuel equipment and a cylinder-piston group, the V-92S2 diesel engine is at the level of the best world models, and surpasses most in terms of economy and specific mass-dimensional indicators. The weight of the В-92С2 engine is only 1020 kg, which is more than 2 times less than the weight of the AVDS-1790 (USA), C12V (England), UDV-12-1100 (France) engines. In terms of overall power, the V-92S2 surpasses them by 1.5 - 4.5 times, and in terms of fuel efficiency - by 5-25%. has a torque reserve of 25-30%. Such a reserve greatly facilitates machine control, increases maneuverability and average speed. The T-90 tank is one of the best serial images of armored military equipment in the world due to the highest combat effectiveness, acceptable cost and amazing reliability.

Let's go back to our life in the Polar Mountains. Being engaged in geological research, I again found myself at the facility where a self-propelled tractor SU-100 has been growing into the tundra for half a century. She, like three similarly reconstructed SAU-76 in other places, was abandoned in the early 60s of the last century in the open air by uranium geologists. To assess the condition of the insides of the V-2-34 diesel, I habitually opened the nozzle hatch in the head cover of the left cylinder block. What I saw amazed me. Shiny mirrors on the camshafts, all covered with a thin layer of oil.

It's as if the engine had just been stopped rather than 50 years ago. All fuel pumps (high-pressure fuel pumps and BNK), as well as the air start distributor, were apparently borrowed at one time by passing AT-S-chiks. The right intake manifold is loose. Starter and alternator removed. The rest was all in place and not very rusty.

After a little consumption with a sledgehammer, the control rods came to life, passing along the bottom of the hull from the driver's seat to the main and side clutches and brakes. The main one turned off by pressing the pedal, but the engine did not want to turn over by the flywheel, it was stuck. Those. in any case, it is not suitable for work without a bulkhead. Having estimated the amount of work, the necessary equipment and strength, I returned to my geological camp.

Taking advantage of the wet weather that was not working for the geologist, the next day with a group of student youth began to dismantle the cylinder head of the left collapse of the V-2-34. Absolutely all nuts were unscrewed without problems, even the nuts of the main anchor rods.

When lifting the cylinder head, the latter stuck with a gasket and did not want to separate from the block surface. As it turned out later, it was necessary to take away the head with a shirt and sleeves. But this became clear much later, when disassembling the GT-T diesel engine, which at that time was standing right there, next to the "tank". After the cylinder block, dressed on the anchor pins, remained in the place of the left camber, and the cylinder head assembly was taken to the side, another miracle appeared. All rubber seals, both anchor shafts and bypass tubes made of natural rubber, honey-colored, remained elastic.

My overgrown face was reflected in the cylinder liner mirrors. Fingers automatically ran along the upper edges of the mirrors - the wear on the sleeves was almost not felt. But there was no time to dismantle the pistons. At that time, I was not going to change the cylinder-piston group on my B-6A. Nevertheless, diesel fuel with used oil was poured into the cylinders, and the mirrors were additionally coated with grease. The entire left camber was wrapped in an oiled tarpaulin for the winter.

Some time later, due to the age of the car, the main clutch jammed at the base, so that one of the rods from the shutdown leash was thrown through the ejector into the street. In parallel with the replacement of the clutch, he began to prepare the replacement of the diesel cylinder head with the one brought from the "tank", relatively new in terms of wear and at the same time old in age. By the way, my head was no longer my own.

I changed it to the head of the main collapse of the A-650 diesel engine, left over from the AT-C (product 712) and kept in my reserve, complete with a block and pistons. Then I did not change the piston because of the decent output on the liners of this block. When I removed the cylinder head from my engine, I was distressed and puzzled by the very poor condition of the mirrors.

In addition to normal wear and tear and decent wear, there were ring scratches on the liners, similar to traces of sticking piston rings or cracks. It really could be. In history, there was a case of movement without water in a system of 300 meters, after it was dumped through a torn pipe. Then I changed the cylinder head along with the gasket and rubber seals of the bypass pipes. Here I had to regret the piston left on the "tank"!

Winter passed for various other things and worries about the base. My tractor was disassembled. Already in the summer I asked a friend to drive a GAZ-34039 to get spare parts for a piston.

We went to GAZ to pick up the piston.

When we approached our lonely self-propelled vehicle, it turned out that someone curious, most likely a reindeer herder, had scattered my packaging at the beginning of summer. There was water in the cylinders. The cylinders weren't so perfect anymore. I regretted not taking everything at once. But, as it turned out, I still could not have done it without disassembling the right camber. We pulled off the left block of cylinders. But to remove the pistons from the connecting rods, you must gradually turn the crankshaft.

The cylinder blocks B-2-34 are removed. The motor spins freely

And he did not turn - he stood as if glued. The engine began to crank only after removing the nuts of the stitching and anchor rods of the right camber. The pistons went up along with the entire block and head. It became clear, and after removing the cylinder head, it was clear that the pistons in two cylinders with open valves were simply rusted. It took a little tinkering before the cylinder block was lifted off the pistons and set aside.

The engine without cylinders rotated easily and we proceeded to dismantle the pistons, which, as you know, should be replaced in pairs with liners. Field technology - the piston is carefully warmed up by a blowtorch and beaten into the end of the piston pin with a non-ferrous metal punch. After reaching a sufficient temperature, the pin moves freely until the piston is free from the connecting rod and remains in the seat until it cools.

Since the left-hand camber cylinders still suffered from premature de-preservation by an unknown intruder, it was decided to take all the pistons so that there was plenty to choose from for the inline B-6A kit. For 2 revolutions of the crankshaft behind the fan wheel, all pistons with fingers were packed into boxes. It remained to load into the GAZon and pack the extracted two cylinder blocks, removed fasteners and tubes. In the evening we set off on our way back. With the self-propelled tractor, my sense of duty remained ...

Preparation of the piston engine and assembly of the engine took place in late autumn. According to the plan, it was supposed to disassemble the native cylinder block V-6A GT-T and press the liners from V-2-34 into it.

But it turned out that the sleeves that had worked for 33 years in the silumin shirt of the block did not want to leave it either with a sledgehammer or with a puller. The stripper bar was bent. The sleeve was pushed 3 mm with a sledgehammer through a copper bar. Obviously, the entire jacket of the block had to be heated before extracting the sleeves.

But I remembered about the stored block from the A-650 made of aluminum alloy. Then I didn't want to make the car heavier with a cast-iron block from V-2-34, it is much heavier. But after the AT-S block shirt had been slopped and thoroughly washed, I saw cracks in it between the cylinder seats.

It is clear that such a head is only suitable for scrap or as a visual aid. There was nothing to do but to assemble a block in a cast-iron jacket. When washing and cleaning the disassembled cylinder blocks B-6A, A-650 and B-2-34, I was struck by the strict conformity of the casting, despite the difference in the years of manufacture and materials (silumin and cast iron), as well as the perfect elasticity and the fresh smell of rubber that emanated from the O-rings removed from the sleeves. They were brown rubber. Uncasing the V-2-34 block, as well as the A-650 block, was easily performed with a screw puller.

The liners are in good condition, and the pistons from them were soaked in a barrel of diesel fuel and washed. Most of the piston rings are stuck in their grooves.

Rings of pistons removed from V-2-34 in comparison with the rings of worn pistons of the GT-T diesel engine, after cleaning, move without play in the grooves. My old pistons were no longer usable due to broken grooves. In preparation for assembling the engine, the piston rings were fixed with cotton thread. The visual difference between the B-6A and B-2-34 pistons is only that the bottom of the B-6 piston is smooth bowl-shaped inside, and the bottom of the piston from the "tank" is made in the form of a lattice of heat sink fins. The pistons from V-2-34 were installed without unnecessary difficulties on the connecting rods of my V-6A in the same way as they were removed.

The assembly of the unit, like all the preparation work, was carried out on a table in a warm and well-lit environment. O-ring rubber liners, together with seals and a gasket under the cylinder head, were purchased in advance from LLC "Neva-diesel", St. Petersburg. In the end, it turned out that the cylinder block B-2-34 was reassembled in a cast-iron jacket with 6 liners selected from 12. For control, the unit, ready for installation, was subjected to hydraulic tests. During the day, it was filled with diesel fuel on the plane of the cylinder head mirror installation.

As you know, the requirements for military and strategic products are more severe than for "civilian" equipment. Since their actual service life often exceeds thirty years - not only in Russia, but also in the armies of most countries.

If we are talking about tank engines, they, naturally, must be reliable, undemanding to the quality of fuel, convenient for maintenance and some types of repairs in extreme conditions, with a resource sufficient by military standards. And at the same time regularly give out basic characteristics. The approach to the design of such engines is special. And the result is usually decent. But what happened to the V-2 diesel is a phenomenal case.

Painful birth

His life began at the Kharkov Locomotive Plant named after V. Comintern, whose design department in 1931 received a state order for a high-speed diesel engine for tanks. And it was immediately renamed to the diesel department. The task stipulated a power of 300 hp. at 1600 rpm, while the crankshaft rotational speed typical of that time did not exceed 250 rpm.

Since the plant had not done anything like this before, they began development from afar, with a discussion of the scheme - in-line, V-shaped or star-shaped. We settled on a V12 configuration with water cooling, starting from an electric starter and Bosch fuel equipment - with a further transition to a completely domestic one, which also had to be created from scratch.

First, they built a single-cylinder engine, then a two-cylinder section - and it took a long time to debug it, having achieved 70 hp. at 1700 rpm and a specific gravity of 2 kg / hp. The record low specific gravity was also specified in the assignment. In 1933, a workable, but unfinished V12 passed bench tests, where it continually broke, smoked terribly and vibrated strongly.

The BT-5 test tank, equipped with such an engine, could not reach the test site for a long time. Either the crankcase cracked, then the crankshaft bearings collapsed, then something else, and to solve many problems it was necessary to create new technologies and new materials - first of all, grades of steel and aluminum alloys. And purchase new equipment abroad.

Nevertheless, in 1935, tanks with such diesel engines were presented to the government commission, additional workshops were erected at the KhPZ for the production of engines - the "diesel department" was transformed into an experimental plant. In the process of fine-tuning the engine, its secondary purpose was taken into account - the possibility of using it on airplanes. Already in 1936, the R-5 aircraft with the BD-2A diesel engine (the second high-speed aviation diesel engine) took off, but this engine was never in demand in aviation - in particular, due to the appearance of more suitable units created by specialized institutes in these same years.

In the main, tank direction, the matter advanced slowly and heavily. Diesel still ate too much oil and fuel. Some parts broke down regularly, and too smoky exhaust unmasked the car, which the customers did not particularly like. The development team was reinforced with military engineers.

In 1937, the engine was named B-2, under which it entered world history. And the team was reinforced once again with the leading engineers of the Central Institute of Aviation Motors. Some of the technical problems were entrusted to the Ukrainian Institute of Aircraft Engine Building (later it was attached to the plant), which came to the conclusion that it was necessary to improve the accuracy of manufacturing and processing of parts. Its own 12-plunger fuel pump also required tweaking.

On state tests in 1938, all three V-2 engines of the second generation failed. The first had a jammed piston, the second had cracked cylinders, and the third had a crankcase. As a result of the tests, almost all technological operations were changed, the fuel and oil pumps were changed. This was followed by new tests and new changes. All this went in parallel with the identification of "enemies of the people" and the transformation of the department into a huge State Plant No. 75 producing 10,000 motors a year, for which the machines were imported and installed in hundreds.

In 1939, the engines finally passed government tests, receiving a "good" rating and approval for mass production. Which was also debugged painfully and for a long time, which, however, was interrupted by the hasty evacuation of the plant to Chelyabinsk - the war began. True, even before that, the B-2 diesel engine passed its baptism of fire in real military operations, being installed on heavy KV tanks.

What happened?

The result was a motor, about which they would later write that, in terms of design, it was much ahead of its time. And for a number of characteristics, for another thirty years, it surpassed analogues of real and potential opponents. Although it was far from perfect and had many areas for modernization and improvement. Some experts of military equipment believe that the fundamentally new Soviet military diesel engines, created in 1960-1970, were inferior to diesels of the B-2 family and were adopted only for the reason that it became indecent not to replace the “outdated” with something modern.

The cylinder block and crankcase are made of an aluminum-silicon alloy, the pistons are made of duralumin. Four valves per cylinder, overhead camshafts, direct fuel injection. Duplicated starting system - electric starter or compressed air from cylinders. Almost all of the datasheet is a list of advanced and innovative solutions of the time.

It turned out to be ultra-light, with an outstanding specific gravity, economical and powerful, and the power was easily varied by local changes in the operating speed of the crankshaft and the compression ratio. Even before the start of the war, there were three versions in constant production - 375-, 500- and 600-strong, for vehicles of different weight categories. By attaching a pressurization system to the V-2 from the AM-38 aircraft engine, we received 850 hp. and immediately tested it on an experienced KV-3 heavy tank.

Classification:	Main marine diesels
Product brand:	3D12A, 3D12, 3D12AA, 3D12A-1, 3D12-1, 3D12-1A, 3D12A-1A
	TU24.06.5602-73
Power, speed	3D12A, 3D12, 3D12AA -300hp, 1500rpm 3D12A-1, 3D12-1, 3D12-1A, 3D12A-1A -300hp, 1350rpm
Application of clause when ordering	Powered by a propeller. 3D12A, 3D12A-1, 3D12AA, 3D12A-1A - aluminum. crankcase execution. 3D12, 3D12-1, 3D12-1A - cast iron. crankcase execution. 3D12AA, 3D12A-1A, 3D12-1A - with alarm and protection. 3D12Br - without RRP, cast iron. execution. Right or left rotation is negotiated, with or without RRP. RRP for forward travel 1: 2.04 or 1: 2.95, for reverse travel 1: 2.18 for all versions. With or without PTO. River or Maritime Register Certificate.

Specifications

Diesels of type 3D12, 3D12A are intended for installation on ships of various purposes as main ship diesel engines powered by a propeller.

These diesels are high-speed, four-stroke with direct fuel injection. Type 3D12A and type 3KD12N - twelve-cylinder with a V-shaped arrangement of cylinders and a collapse of blocks 60 0. Diesel engines of type 3D12A are manufactured with an aluminum crankcase. The rest are only with a cast iron crankcase.

Cooling system - liquid, circulating, double-circuit, with separate water-to-water and water-to-oil coolers and thermostats. To pump water along the external circuit of the cooling system on diesel engines, a seawater pump is installed.

Lubrication system - circulating, under pressure with a "dry" sump, with an electric pump for prestarting pumping of the system.

Diesel engines are equipped with a reverse gear, consisting of a gearbox and a hydraulically controlled multi-plate clutch designed to connect and disconnect the propeller from the crankshaft, as well as change the direction of rotation of the ship's propeller. Several models of each diesel engine are produced, which differ in the direction of rotation of the output shaft of the reverse gear: right (clockwise) and left (counterclockwise), looking from the side of the reverse gear, as well as reduction to forward and reverse.

At the request of consumers, for replacement of expired diesel engines 3D12 and 3D12L can be supplied without a reverse gear:
-3D12ABr - 310 hp at 1500 rpm of left-handed rotation of a c / v with a cast-iron crankcase for operation with a reverse gear of type Sb.1225-00-5 or Sb.525-01-13;
-3D12ALBr - 310 hp at 1500 rpm of right-hand rotation of a c / v with a cast-iron crankcase for operation with a reverse gear of type Sb.1225-00-5 or Sb.525-01-13;

It should be borne in mind that the reverse gear reverses the direction of rotation of the output shaft (propeller).
Diesels can be equipped with an additional power take-off shaft up to 30 HP. (PTO).
Diesel engines are started by an electric starter or compressed air. To charge storage batteries, diesel engines are equipped with an alternator with built-in rectifier, voltage regulator and radio interference suppression device.

Diesel engines can be controlled and monitored from the control panel directly on the diesel engine or from the control panel located in the ship's wheelhouse.

At the request of consumers for special ships, diesel engines of the 3D12A, 3D12-1 and 3D12A-1 types can be supplied complete with the FK6501 system (diesel functional control device), which, with the mechanisms, devices and relays (sensors) installed on them, provides emergency warning signaling and protection by controlled parameters (overheating of coolant. liquid and oil, oil pressure drop and "runaway"). These diesels have the following brands: 3D12AA, 3D12ALA, 3D12A-1A, 3D12AL-1A, 3D12-1A, 3D12L-1A.

Diesels meet the requirements of the Rules of the Russian Maritime Register of Shipping and the Russian River Register.

Characteristics
Power, hp: - full (overload, not limited by the time of continuous operation) at the outlet flange of the reverse gear
In reverse mode, not less
Rotation frequency corresponding to full power, rpm
Specific fuel consumption at full power, g / hp h.
Specific oil consumption for waste, g / hp h
Reverse gear ratio (reduction): - forward
To reverse
Duration of switching of the reversing clutch, no more, s
Seawater pump suction head (NZV), m
Weight, kg
Overall dimensions, mm: - length
Service life up to the 1st bulkhead (warranty operating time), h
Assigned resource before overhaul, h

Direction of rotation (right or left); suction head NZV (for 3KD12N-520); diesel engines of type 3D6S2 and 3D12 with or without a reverse gear, with or without APSiZ system, the presence of a PTO, as well as the Certificate of the Maritime or River Register is negotiated when placing an order (contract).

Contents of delivery:
1. A set of accessories (batteries with connecting wires, water and oil coolers, thermostats) is specified when ordering;
2. Single set of spare parts;
3. Tool kit;
4. A set of operational documentation.