Modern piston engines internal combustion(ICE) can be classified based on criteria such as the type of fuel used and the arrangement of the cylinders. If with the division of engines based on the type of fuel, everything is more or less clear even to people who are very far from technology, then with the division according to the arrangement of cylinders, everything is not so obvious. In this material, we will consider one of the types of internal combustion engines with an unusual arrangement of cylinders, namely a boxer engine. Here you will learn about what a boxer engine is, how it works, what its pros and cons are and where it is used.

The design and features of the boxer engine

Scheme of operation of a boxer engine

Opposed internal combustion engines are those whose cylinder camber angle is 180 °. The pistons in them move in a horizontal plane, and mirror each other. This means that they reach their highest point at the same time. By the way, this is precisely one of the main differences between boxer power units and the more common V-shaped ones: in them, the movement of the pistons is carried out synchronously (when one of them is at the top point, the second is located at the bottom).

Due to this arrangement of cylinders, boxer engines have a low center of gravity. In addition, their height is significantly less than that of the V-shaped, they are more "flat" and take up less space in engine compartment. One of distinctive features boxer engines is the presence of two gas distribution mechanisms (they have a crankshaft, as well as a V-shaped one, most often). As for the principle of operation of these motors, it is exactly the same as that of all other internal combustion engines: the movement of the pistons that drive the crankshaft is carried out due to the pressure of the gases formed during the combustion of the fuel mixture.

Types of boxer engines

To date, there are three main types of boxer engines:

• boxer;
• OPOC;
• 5 TDF.

They differ from each other mainly in the way in which the pistons move in them.

boxer. In boxer engines of this type, each piston is located in its own cylinder, and they are located at a certain distance from each other, which always remains constant. This is precisely what main feature such power units. Since in the process of functioning the movement of their pistons resembles the movements of boxers in the ring, they received the name Boxer.

OPOC. This abbreviation stands for Opposed Piston Opposed Cylinder, and the design feature of boxer engines of this type is that they have two pistons in each of the cylinders. They move towards each other. OPOC boxer engines are 2-stroke and do not have cylinder heads or valve trains. Thanks to this design, these power units are lightweight, and they are both gasoline and diesel.

5 TDF. This type of boxer engine is domestic development. At one time it was created specifically for installation on T-64 tanks, a little later it was used in the T-72. Just like in the OPOC boxer engine, its cylinders contain two pistons that move towards each other, but unlike it, each of them has its own crankshaft. The combustion chambers in 5 TDF boxer engines are located between the pistons, they work both on gasoline and on diesel fuel. Now these power units are no longer produced.

Pros and cons of boxer engines

Crankshaft and pistons of a boxer engine

Like other types of internal combustion engines, boxer powertrains have both pros and cons. As for the advantages, one of the most significant of them is a very low level of vibration during operation. These motors owe this precisely to the opposite arrangement of their pistons. The fact is that when moving, they mutually balance each other, and the imbalance of forces that leads to vibrations is almost completely absent.

This advantage of boxer engines entails another significant plus: since there are practically no vibrations, the wear of moving parts is much slower than in, say, V-engines. Accordingly, the resource of such motors is very large: practice shows that the value of their mileage up to overhaul is about half a million kilometers. Some owners of cars with boxer engines claim that this figure is even higher in practice, ranging from 600,000 to 700,000 kilometers.

Another plus of this type of power units is the low center of gravity. That is why they are often installed on sports cars. When cornering at high speeds, boxer engines provide increased stability of the machines. In addition, as mentioned above, the advantage of motors of this type can be considered their small height. In fairness, it should be noted that at the same time they are somewhat wider than power units of other types (for example, the same V-shaped motors).

As for the disadvantages of boxer engines, the main ones are the following: high cost and difficulty in repair. The design of such motors implies high manufacturing accuracy of many of their main elements, the use of expensive high-strength materials. In addition, their assembly and adjustment is much more complicated than similar procedures for V-shaped or in-line internal combustion engines. Diagnosing and troubleshooting boxer engines is only possible with specialized equipment and specially trained personnel. It goes without saying that even a minor repair of such motors costs a lot for the owners of the cars on which they are installed.

Also significant disadvantage boxer engines are considered significant oil consumption. However, in terms of such an indicator as fuel consumption, they are still inferior to modern V-shaped and in-line power units.

Scope of boxer engines

Boxer engines are not as widely used as V-twins and in-line engines, but there is an automaker that has been installing this type of engine in its cars for half a century. This is the famous Japanese company Subaru. In addition, boxer units can be found on some Volkswagen models and Porsche, they were once equipped soviet motorcycles"Ural" and "Dnepr", Hungarian buses "Ikarus".

It should be noted that in recent years, interest in power units of this type has increased significantly. According to some reports, research and development to improve the OPOC boxer engines, conducted by a group of American engineers, is funded by Bill Gates.

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After the creation of the world's first internal combustion engine, it became necessary to improve and increase its power. When the solution in the form of increasing the number of cylinders has exhausted itself, the search for the optimal arrangement of the cylinders in the power unit began. One of the most successful options was their horizontal arrangement, and an engine of a similar design became known as a boxer.

The device and principle of operation of the boxer engine

Home hallmark boxer engine is the location of the pistons, the angle between which is equal to 180 o. That is, the movement of pairs of pistons in it occurs in a horizontal plane. Each pair has its own gas distribution shaft, which, together with the valves, unlike the usual inline engine are located horizontally. This type of motor is widely used on cars manufactured by Volkswagen Group and SUBARU, they were equipped with Soviet motorcycles "Ural" and "Dnepr", the bus "Ikarus".

The horizontal arrangement of the cylinders allows to reduce vibrations, mutually compensating them, and to achieve a smoother ride. As a result, the engine has the ability to smoothly increase power without noticeable jerks, while not wearing out so quickly. The boxer engine is located in the car near the chassis, which moves the center of gravity lower, thereby increasing stability and control vehicle.

Boxer engines are available in petrol and diesel versions. In modern versions of such power units, in order to achieve economical fuel consumption and environmental friendliness, the following technical solutions are used:

1. Reduced volume of the combustion chamber, increasing the compression ratio.
2. The use of forging technology in the manufacture of parts piston group which reduces their weight.
3. Application of technologies for changing gas distribution phases.
4. The use of a new type of oil pump, thanks to which engine lubrication is performed better.
5. Structurally new system cooling, which has 2 circuits: a separate circuit of the cylinder block and its head.

Boxer engine types

The boxer engine has been improved for more than 70 years since its inception, which led to the appearance of its following modifications:

1. Boxer is Subaru's proprietary development. It differs by the equal removal of the pistons from each other: when one is located at TDC, the second is at the bottom.

2. OROS. For a long period it was not in demand, but recently the engine has been installed on cars and improved. The design uses one crankshaft, and in each cylinder there are 2 pistons working towards each other.

3. Tank TDF. Used on tanks developed in the USSR. This two stroke engine used only on military equipment.

Boxer engine: pros and cons

The main advantages of the boxer engine:

1. Balanced work and high efficiency. This is due to the horizontal arrangement of the pistons, when they provide a counterweight to each other. The boxer six is ​​considered the most efficient model of such an engine in terms of handling and balance.
2. Low center of gravity in the car, increasing its stability. Such an advantage is not very useful for a city car, but it is very necessary for sports cars, for which stability on the road is vital. high speed.
3. High reliability and durability. Most of the boxer engines are able to work 500 thousand km before overhaul, which is much higher than the service life of the engines of many budget cars including Volkswagen.
4. Compliance with high standards passive safety. When frontal collision such an engine moves down without harming passengers and the driver.

Weaknesses of Opposites:

1. Design features of the unit that make repairs too expensive. To service such an engine requires the high professionalism of the master, as well as the use of special equipment.
2. The large dimensions of the engine allow it to be installed only in the longitudinal direction.
3. due to the complexity of the design.

Difficulties in the repair and maintenance of a boxer engine

All the advantages of a boxer engine are fully revealed in its six-cylinder version. Units with a smaller number of cylinders are practically the same as traditional ones in terms of characteristics. The main problem the owner of a car with an opposite will be difficult to maintain due to the horizontal arrangement of the cylinder and the small free space under the hood for this reason.

The driver is able to independently change the oil in it, and other types of work can be done only in the auto center. So, simple replacement candles must be carried out by a qualified specialist, and a beginner, performing this operation on his own, can damage the cylinder head. In the event of a malfunction, the repair of such an engine should also be carried out at a specialized service station.

The only thing that can be successfully carried out on your own is to deal with soot on the parts of the piston group and the combustion chamber, which is formed when using low-quality fuel, driving without load and on a cold engine. For this, a carbon removal technique is used, called decarbonization, which is divided into soft and hard. With a hard one, a softening liquid is poured through the hole from the turned out candle for 12 hours, which destroys soot.

For a boxer engine, this method is not suitable, since unscrewing the candles in it is a rather problematic procedure, it requires skills and a special tool. But you can apply a mild cleaning in the form of a special cleaning additive to the oil. A run of 200 km will be quite enough for its operation, after which the oil in the power unit must be replaced.

If on your Subaru, this does not always portend an expensive repair.

Prospects for the use of boxer engines

Most well-known car manufacturers that use a boxer engine in the produced models are Porsche and Subaru. The first is experiencing a period of prosperity, and the second is not better times. This is due to the focus of products on different target audience: in the first case, Porsche cars are positioned as elite products, implying high manufacturability and maintenance costs, and in the second case, middle-class cars for those who like to have racing technology on a regular car.

For a Porsche, customers are willing to pay fairly large sums of money, but a car with an engine that is slightly more than 100 hp in power. with., which after a run of 130 thousand km. expensive repairs will be needed, especially if it is turbocharged, may be preferred only by the most dedicated customers. But given the fact that many funds and developers are engaged in improving the opposites, as well as the fact that they are also used in motorcycles, it allows us to remain confident that the opposed engines will be relevant for a long time to come.

Good afternoon. From this article you will learn what a boxer engine is, what are its advantages and disadvantages in comparison with classic internal combustion engines.

It is well known that boxer engines are installed only on certain models of cars, which is why they attract a lot of attention.

Opposite is a type of internal combustion engine (ICE) in which the pistons move horizontally towards each other and back. The angle of the pistons is 180°. This this modification different from the conventional V-twin engine. In it, in addition to the first pair of pistons, there is also a pair of neighboring ones, which, during the movement of the first pair, occupy the same position in relation to each other.

A boxer engine can have a different number of cylinders, but it is always even. Currently, there are from 2 to 16 cylinders in the design. The latter variety has been installed on some sports models Porsche. The most common are 4 and 6-cylinder engines.

Types of boxer engines.

As already mentioned, the movement of the pistons in the motor can occur in different ways. Depending on the direction of this movement, several types of "opponent" are distinguished.

The first version is the “boxer”, so named because the pistons are directed towards each other, and are very similar to a fight in a boxing ring. Due to the fact that each piston is mounted on a separate connecting rod by means of a connecting rod crankshaft, it turns out that they are located each in its own cylinder. Accordingly, during an equal distance from the axis of the engine to the greatest distance, they are located directly opposite each other. This type of organization is often used in engines car series Subaru and Porsche.

The second option for building an “opposite” is “OROS”. It is two-stroke. Each cylinder of this type of engine simultaneously contains a pair of pistons (the first provides the input of the mixture, the other - the output of combustion products), mounted on one crankshaft. Both pistons work on the same crankshaft. Thanks to such an organization, the mass of the “opposite” has significantly decreased, which made it possible to expand the scope of its use.

Boxer engine advantages:

One of the main advantages of the “opposer” is the low center of gravity. This, in turn, contributes to the best handling of the car, enhances its stability, which is very valuable, especially for sports cars, for example, when cornering at high speed. Structurally, everything looks quite simple: the understated motor is adjacent to the transmission on the same axis, due to which power is transferred much more efficiently than with its usual location.

The second undoubted advantage of the boxer engine is the almost complete absence of vibrations in it, with the exception of those that arise from inertial forces that tend to turn it around a vertically located axis. The engine runs smoothly, as the movement of the adjacent pistons is smooth.

The third plus, inextricably linked with the second, is that the crankshaft, due to the mass balance in the "opposite", is installed on only three bearings, which significantly reduces the length of the motor, and, accordingly, its weight.

Another advantage is the provision of passive safety. This is due to the fact that in the event of a head-on collision of cars, the motor goes under the body of the car without threatening the lives of passengers.

"Oppozitnik" in working condition makes a characteristic sound, thanks to which it can be distinguished from other internal combustion engines. This feature is also considered an advantage by many drivers.

Disadvantages of a boxer engine:

Unfortunately, the design of the motor is also its disadvantage, since repair work quite laborious. It is required to remove the entire assembly from the car, even for minor repairs. The laboriousness of the work translates into a high repair cost for the car owner. In addition, highly skilled workers are also required, which makes it impossible to carry out self repair in the garage.

boxer engine- special type power plant, resembling a traditional internal combustion engine, in which the cylinders have a special arrangement - horizontal. In the people, such units are known as "boxers". The motor received such a nickname due to the fact that the pistons move either away from each other or towards each other. In this case, the pair of pistons is in one position, for example, from below.

The very first sample appeared in 1938 thanks to the efforts car company Volkswagen. Then the unit was a 4-cylinder boxer, the volume of which was 2 liters. The maximum power of the power plant reached 150 Horse power.

The boxer motor has become very widespread. Today, the production and installation of the unit are carried out by such eminent automobile concerns like Subaru and Porsche. Previously, it was possible to find the engine on models from Toyota, Volkswagen, Honda, Ferrari. Similar installations are used in motorcycles, Ikarus buses and some military equipment (for example, tanks).

The principle of operation of the boxer engine and its device

To fully understand what a boxer engine is, you need to familiarize yourself with its structure. As noted above, this is an internal combustion engine, which has a special structure - a pair of pistons moves in a horizontal plane (not up and down, but from left to right). The second, adjacent, is in the same position.

The number of such cylinders varies from 2 to 12 (their number is always a multiple of two). The most common samples have 4 and 6 cylinders. For sports cars, 8- and 12-cylinder engines were developed. Professionals note that the principle of operation of 2- and 4-cylinder boxers is no different from traditional engines. Those that have six cylinders have their own characteristics.

Types of boxer engines

The principle of operation of a boxer engine also varies depending on the features of its device. Even such a simple unit can have several variations in the operation of the pistons. Therefore, the following types of motors are distinguished:

1. boxer boxer often used in the production of Subaru vehicles. How does a boxer engine of the claimed type work: the pistons are located at a predetermined distance opposite each other, for example, if the first is fixed at a certain distance from the axis of the engine, then the second will take a similar position. Moreover, they are located each in a separate cylinder. The described principle of functioning resembles a boxing match, hence the name of the type.
2. OROS has a completely different principle of construction and the order of operation of the pistons. Such devices are two-stroke. One cylinder has two pistons at once, which are attached to one crankshaft. The first is responsible for the intake of the mixture, the other for the timely exit of combustion products. This design does not have a head, which is often found on the cylinder block. The advantages of the OPOS boxer engine are that the pistons function in favor of a single crankshaft. This type of device has a small mass and is smaller in size. Consequently, the scope of application has significantly expanded. In addition, this engine can run on different fuels - diesel or gasoline. Finally, here are the main benefits:
   • pistons travel a much shorter distance, as a result of which the friction force is significantly reduced, which negatively affects wear resistance;
   • efficiency increases, because harmful gases do not affect the combustion chamber, but put pressure on the pistons;
   • the motor is 30-50% lighter than usual;
   • the boxer engine has fewer parts (50% on average);
   • profitability;
   • lack of a valve drive system.
   • the motor takes up much less space under the hood.
   However, it is worth remembering that the ERF is at the development stage, so many unforeseen problems may arise during operation.
3. tank engine (5TDF, designed specifically for the T-64 and T-72). The resource of the boxer engine is designed for military equipment of large dimensions. Here the pistons share one cylinder and they move in the same direction, but each has its own separate crankshaft. The place where the fuel ignites (combustion chamber) occurs when the gap between the pistons becomes minimal. As with OROS engines, air is admitted into the cylinders, and unnecessary gases are removed by turbocharging. The counter stroke of the pistons made it possible to design a compact but powerful unit. The power plant has a maximum number of revolutions of 2000, and a power of 700 horsepower. The volume, respectively, reached 6 and 13 liters.

Benefits of a boxer engine

Each element in the automotive body has its own advantages and disadvantages. The advantages of a boxer engine are as follows:

• lowering the center of gravity of the vehicle, which positively affects its stability;
• the resource of the motor will certainly increase (if operated correctly, it reaches about 1 million km);
• due to the special interaction of the pistons, the level of vibration and noise reduction is reduced.

Cons of a boxer engine

If the boxer engine has advantages, then there are certainly certain disadvantages:

• costly self-service - requires the involvement of professionals;
• expensive and complex repairs, because the components are distinguished by their increased cost;
• the high cost of the power plant;
• design complexity;
• increased oil consumption during operation.

Despite the disadvantages described above, many automakers equip their models with just such units. Development companies carefully weigh all the pros and cons before using just this type of motor. Main plus - great opportunities and broad perspectives.

So, all the negative aspects, in fact, come down to expensive service, which may affect the choice of most motorists not in favor of the presented units. However, large manufacturers (Porsche, Subaru) believe that quality requires a large investment in service.

For example, a Japanese automaker is not going to return to traditional internal combustion engines, because they believe that in this case they will take a technological step back. Since car models have proven themselves only in the best way, the level of sales does not depend on the prices for service.

Difficulties in the repair and maintenance of a boxer engine

It is important to note that often the positive aspects of these motors are noticeable only in power units, which have six cylinders, but 2 and 4 cylinders are not much different from traditional internal combustion engines.

If you need to carry out some manipulations with this type of engine, then you definitely need to contact the specialists in a car service. You can only change the oil yourself. It is better to entrust even the replacement of candles to professionals, beginners can easily damage the cylinder head. Complete renovation produced only at special service stations.

Timely and systematic decarbonization can extend the service life. This procedure involves cleaning the surface of the combustion chamber, valves and pistons from carbon deposits. The operation is carried out in the autumn season or in March, when it is also very reasonable to check the engine oil.

In the material, we examined what the concept of "boxer engine" means, described the principle of operation, possible pros and cons. We hope that this will help determine the choice of not only the motor, but also the future car model on which a similar power unit can be installed.

A simple layman who is interested in cars does not know much about the boxer engine. Basically, only that the cylinders in it have a horizontal arrangement and such a motor is installed on Subaru. Let's try to expand the horizons of our knowledge and talk about boxer engines.

A boxer engine is an internal combustion engine layout in which the pistons are parallel to the surface in a horizontal plane. In this case, two adjacent pistons are in different positions relative to each other at the same time. Their movement is very similar to the fight in the ring, often the motors are called boxer. One of the distinguishing details is the mounting of each piston on its crankshaft crankpin. In this case, the number of pistons is always divided by two. The most popular are four and six cylinder boxer engines.

Some confuse boxers with a V-shaped motor. Despite some similarities in design, there are significant differences. So in the V-shaped, adjacent pistons are on the same connecting rod journal and, when moving at the same time, are at opposite points in the course of work.

We can highlight the following advantages of this type of engine:

• low center of gravity;
• reduced working vibrations;
• increased safety in a head-on collision.

Each benefit has its own rationale. So a lower center of gravity means better car handling and traction, and the lower position of the motor puts it in line with the gearbox, which significantly improves the efficiency of the transmission of revolutions.

The boxer motor has reduced vibration due to its layout. This allows you to install it on a crankshaft equipped with three main bearings, and not five, as is usually the case. At the same time, the dimensions and weight of the entire structure can be significantly reduced.

High security is also dictated by the low location. In a head-on collision, the engine goes under the passenger compartment, which ensures the survival of passengers in the front seats. Well, in the end, the boxer engine has a characteristic sound of work, not at all similar to the sound of the classic engine.

Nothing happens without flaws, the boxer engine also has them. These include:

• sufficient difficulty of repair work due to design features. Often there is a need to dismantle the engine in order to carry out certain work.
• masters note different cylinder wear due to the horizontal arrangement of the pistons and further high oil use.

Today, the boxer engine has become a hallmark of brands such as Subaru and Porche. Previously, it could be seen on cars of various brands originating from Germany, the USA, Japan, and Italy.

Subaru has been putting these engines in their cars since 1963. Four-cylinders have three generations: the EA, EJ and FB series. Six-cylinder steels on the conveyor a little later, but also have three series: ER, EG and EZ.

Most engines of this type run on gasoline and have multiport fuel injection with an overhead gas distribution system. There are motors with one (SONS) or two (DOHC) camshafts, driven from the crankshaft by a belt or gear drive. In all motors of this type, the gas exchange scheme is based on four valves. There are also turbocharged boxer engines.

The third generation of engines is today the peak of engineering, which has a small size, simple design, low fuel consumption and reduced emissions. To achieve all these indicators, the following was done:

• the degree of compression of the mixture is increased by increasing the piston stroke and reducing the volume of the combustion chamber;
• parts have become much lighter due to their execution by forging rather than casting;
• the variable valve timing system (AVCS) was put into operation;
• engine life and lubrication quality increased due to the new oil pump;
• cooling is performed separately for the engine head and cylinder block using a second circuit, which increased efficiency.

In 2008, the boxer diesel engine introduced by Subaru appeared for the first time. It has 4 cylinders and 150 hp. Its layout uses a progressive injection and turbocharging system.

Porsche also mounts boxer engines on some of its models. This is 911, Boxter, Cayman. They use six-cylinder engines. Boxer engines with eight and twelve cylinders have also been developed for cars that participate in races.



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