What is a boxer engine? The principle of operation, the pros and cons of the engine. Subaru boxer engine: pros and cons

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

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

The boxer motor is very widespread. Today, such eminent automobile concerns as Subaru and Porsche are engaged in the production and installation of the unit. 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 structure

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 with a special structure - a pair of pistons moves in a horizontal plane (not up and down, but from left to right). The second, adjacent one, 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 designs have 4 and 6 cylinders. 8- and 12-cylinder engines have been developed for sports cars. Professionals note that the principle of operation of 2 and 4-cylinder boxers is no different from traditional engines. Those with 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 design. 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 manufacture of Subaru cars. How does the 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 engine axis, 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 push-pull. 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 release 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 is lightweight and smaller. Consequently, the scope of application has expanded significantly. In addition, the specified engine can operate on different fuels - diesel or gasoline. Finally, we will point out the main advantages:
   • the pistons travel a much shorter distance, as a result of which the friction force is significantly reduced, which negatively affects the wear resistance;
   • efficiency increases, because harmful gases do not affect the combustion chamber, but put pressure on the pistons;
   • 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 OROC is under development, 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 large military equipment. Here, the pistons share one cylinder and 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 means of turbocharging. The opposite 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 capacity of 700 horsepower. The volume, respectively, reached 6 and 13 liters.

Advantages 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 has a positive effect on its stability;
• the resource of the motor will certainly increase (if properly operated, it reaches about 1 million km);
• due to the special interaction of the pistons, the level of vibration and noise emission 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 component parts are distinguished by their increased cost;
• high cost of the power plant;
• the complexity of the design;
• 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. The main advantage is great opportunities and broad prospects.

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

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

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 that have six cylinders, but 2 and 4-cylinder do not differ much from traditional internal combustion engines.

If it is necessary to carry out some manipulations with this type of engine, then you certainly need to contact a specialist in a car service. You can only change the oil on your own. It is even better to entrust the replacement of spark plugs to professionals; beginners will easily harm the cylinder head. Full repairs are carried out only at special service stations.

Timely and systematic decoking 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 fall season or in March, when it is also very reasonable to check the engine oil.

In the material, we examined what the concept of "opposed 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.

Good afternoon. In 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 great attention.

A "boxer" is a type of internal combustion engine (ICE) in which the pistons move horizontally towards each other and back. The piston angle is 180 °. This is how this modification differs from a conventional V-shaped engine. In it, in addition to the first pair of pistons, there is also a pair of adjacent 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 variant has been fitted to some of the Porsche sports models. 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 "opposites" are distinguished.

The first version of the performance is the "boxer", named so because the movements of the pistons in it are directed towards each other, and are very similar to a fight in a boxing ring. Due to the fact that each piston is installed by means of a connecting rod on a separate connecting rod journal of the crankshaft, it turns out that they are each located in its own cylinder. Accordingly, during the same distance from the engine axis at the greatest distance, they are located directly opposite each other. This variant of the organization is often used in engines of the automobile range of Subaru and Porsche.

The second variant of constructing the "oppositor" is "OROS". It is two-stroke. Each cylinder of an engine of this type contains at the same time a pair of pistons (the first provides the input of the mixture, the other - the output of combustion products), fixed on one crankshaft. In this case, both pistons work on the same crankshaft. Thanks to such an organization, the mass of the "oppositor" has significantly decreased, which made it possible to expand the scope of its use.

Benefits of a boxer engine:

One of the main advantages of the boxer 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 lowered motor is adjacent to the transmission on the same axis, due to which power is transmitted much more efficiently than with its usual arrangement.

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

The third plus, inextricably linked with the second, is that the crankshaft, due to the mass balance in the "opposed", 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 endangering the lives of passengers.

"Opposer" in working order emits 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 at the same time its disadvantage, since the repair work is quite laborious. It is required to remove the entire assembly from the vehicle, even for minor repairs. The complexity of the work translates into a high cost of repairs for the car owner. In addition, high qualifications of workers are also required, which makes it impossible to carry out self-repair in the garage.

A boxer engine is an engine whose cylinders are located horizontally relative to each other. A similar structure scheme has a name: V-shaped engine with a camber angle of 180 degrees. From English the word "opposite" is translated - "located opposite". Consider a boxer engine - the pros and cons.

Features of the boxer motor

Despite the resemblance to a V-shaped engine, the boxer has nothing to do with it. The difference is that in the opposed piston, two adjacent pistons are located in the same plane relative to each other. In a V-shaped engine, the pistons, when moving at certain moments, occupy the position of the upper and lower "dead center". In opposing they simultaneously reach either the top dead center or the bottom. This improvement on the V-shaped engine resulted from the arrangement of the cylinders at an extended angle.

Another innovation was the vertical arrangement of the gas distribution mechanisms. All this freed the design of the power units from imbalance and increased vibrations, and made driving the car as comfortable as possible. Now vibrations from the engine are not transmitted to the body and do not shake the car.

Boxer motors always have an even number of cylinders. The most widespread are four- and six-cylinder engines.

The design features of the boxer-type power unit have significant advantages over other types of motors:

The center of gravity is shifted downward;
economical fuel consumption;
low vibration level;
increased engine resource;
passive safety in a frontal collision.

The center of gravity shifted downwards allows to achieve better stability of the car and optimal handling during active maneuvers and
sharp turns. Roll is significantly reduced during sharp turns. The location of the engine on the same axis with the transmission provides the best transfer of power. The absence of balance shafts saves fuel consumption.

The engine runs smoothly. The low vibration level of the motor is achieved due to the coordinated rotation of adjacent pistons. The arrangement of the crankshaft on three bearings, instead of the usual five, is another advantage of the boxer engine. This significantly reduces engine weight and length.

The arrangement of the pistons in the horizontal plane gives the system greater rigidity, which significantly reduces mechanical losses during the operation of the power unit.

Passive safety is ensured by the fact that in a collision, the engine easily goes down under the car. As a result, the intensity of the impact directed at the passenger compartment decreases.

The increased diameter of the cylinders provides the engine with high revs, which makes it possible to create sports-type models on this basis.

Another feature is the characteristic sound when operating the boxer power unit: it is more pleasant to the ear.

Disadvantages of a boxer engine.

The advantages of a boxer engine are evident. The disadvantages are:

Laborious repairs;
increased consumption of engine oil.

To repair the engine, it is completely removed. However, this is not the problem. Replacement parts are very expensive, and assembling the engine is a headache. If, when repairing an in-line motor, the driver can replace the candles on his own, then in the boxer it is impossible. Any repairs must be carried out on special equipment that is available only at the service station.

The history of the appearance of the boxer

Initially, this type of power unit was used in the military industry, in particular, on domestic tanks. In the future, Ikarus and the Dnepr MT motorcycle drove on similar engines. At this time, two companies are engaged in installing the boxer on their products - Porsche and Subaru.

The first developments appeared in the thirties of the last century, when Volkswagen engineers began to improve the V-shaped and in-line engines. In the sixties, the Japanese firm Subaru took over the idea. In 2008, Subaru launches the first diesel-powered boxer. Distinctive features - a four-cylinder engine with a capacity of 2 liters. Power indicator - 150 l / s.

Video of the principle of operation of a boxer Subaru engine

Despite the high cost of spare parts and service in the service station, the pleasure of driving a car equipped with a "boxer" cannot be compared with anything. High stability, easy handling, responsiveness of the car to all the driver's actions speak for themselves.

The boxer engine is not just a technique that was ahead of its time, but in fact the solution to many problems that are not able to solve many modern traditional engines.

What is a boxer engine? Video

The boxer engine is a special type of power plant that resembles a traditional engine itself, but the cylinders are located horizontally. In common people, this motor was called "boxer". This is due to the movement of the pistons away from each other, or towards each other, towards each other. However, the two pistons are in the same position.

Boxer engine. Photo

The first example is an engine from Volkswagen in 1938. At that time, the unit consisted of a 4-cylinder "boxer" with a volume of 2 liters, with a capacity of 150 horsepower. After that, the motor gained popularity and began to be widely used.

Subaru boxer engine

Today, boxer engines are manufactured and installed by Subaru and Porsche. Until recently, this fate was also shared by Toyota, Honda, Ferrari, and of course, the founder of boxer engines - Volkswagen. Such installations can be seen not only in motorcycles, Ikarus buses, but also in some tanks.

Video about the Subaru boxer engine:

The principle of operation of the boxer engine. Video

To form a final picture of what the boxer engine is, you need to understand its structure. Let's repeat what was said earlier - this is an internal combustion engine, which has one feature - the movement of a pair of pistons is performed in a horizontal plane ... The second pair in the neighborhood is also in a horizontal position.

The total amount of such cylinders can reach 12, of course, counting starts from 2. The number will necessarily be a multiple of two. The most popular designs are 4 and 6 cylinders. Experienced mechanics and professionals noted that the operation of the 2-cylinder and 4-cylinder boxer is not too different from the traditional engine. Features begin to emerge from six cylinders.

Video of the principle of operation of the Subaru boxer engine:

A variety of boxer engines

It will not be news that the principle of operation itself depends on the features of the type of unit. This also applies to boxer engines.

They are divided into:

1. Boxer boxer, which are often used in Subaru cars. As for the principle of their operation, it should be said that the pistons are located at a predetermined distance from each other, at the same distance from the engine axis. But at the same time, each piston is located separately from each other in the cylinders. This principle of operation is similar to boxing fights, hence the name;

   
   Boxer Engine - Boxer. Photo

2. OROS radically differs from the boxer, both in structure and in the sequence of pistons. These units are two-stroke. One of the cylinders is located just behind two pistons that are attached to a single crankshaft. One of them is responsible for the intake of the mixture, the second - for the timeliness of the release of combustion products. In this design, there is no head, which in most cases is located on the cylinder block. TO the benefits of OROC engines refers to the fact that the pistons "work on one crankshaft." This is what makes it possible to create these engines of small size and weight. This leads to a wider scope of their application. Also, this engine works equally well on both diesel and gasoline. With all this, the pistons travel much less distance, and therefore the friction force is several times less, which prolongs the life of the engine. And also, given that it has a smaller size and weight, therefore, two times fewer parts are required for its manufacture. This saves money. Common Lack of ODA engines is that they were not so long ago developed and are being improved to this day. Because of this, unforeseen problems should not be ruled out during its operation;

   
   ОROS is a boxer engine. Photo

3. ... The boxer engine is also designed to operate large military equipment. In this case, the pistons divide one cylinder and move in the same direction, but each has its own crankshaft. The combustion chamber is created at that moment of the minimum distance between the pistons. The similarity with OROC is that air enters the cylinders themselves, and excess gases are removed by turbocharging. This power plant has a capacity of 700 horsepower, the maximum number of revolutions is 2000. The volume is equal to six or thirteen liters.

   
   Tank boxer engine. Photo

Pros of boxer engines

Regardless of the type of motor, boxer engines have common advantages, among which are:

Cons of boxer engines

Of course, there is nothing perfect in the world, which can be said about boxer engines. The disadvantages include:

• A very large amount for service that requires the intervention of professionals;
• High cost of spare parts;
• The complexity of the entire structure as a whole;
• Higher oil consumption during operation.

But even taking into account the above disadvantages, this does not prevent many manufacturers from installing boxer engines on their cars. Before that, all the pros and cons are weighed.

Chief among the pluses is more opportunities and broader perspectives. After all, in fact, all the shortcomings run into money. However, most people are aware of the fact that more money is required for good quality. In addition, the use of boxer engines is the next step in technological development.

Differences between a boxer and in-line four-cylinder engine

Now we will talk about the general features and distinctive features of the Boxer Four and Straight Four in-line and boxer four-cylinder engines. And also about their pros and cons. Below is a short video where everything is described in detail.

Differences between a boxer and in-line four-cylinder engine. Video

1. Both designs operate on the principle of a four-stroke cycle - start, compression, stroke and release.
2. In both designs, a working stroke occurs every 180 degrees of rotation of the number of shafts, but they have a slightly different ignition order.
3. On each engine we see cylinders numbered 1, 2, 3, 4. For the opposite ones, the ignition order is 1, 3, 2, 4., and for the inline 1, 3, 4, 2. So the order of operation of the last two cylinders is changed ... This difference affects how the engine is balanced. On a boxer engine, the cylinder pairs, outward and inward, move together. This means that the first-order inertial force that occurs when the piston reaches top or bottom dead center cancels out. It's the same story with an in-line four-stroke engine - the first order inertia forces cancel each other out, as for the second order inertia force - here the engines start to differ. Second-order inertia forces are created due to the fact that the piston moves faster at the top of the cylinder than at the bottom. When the piston reaches its maximum or minimum dead center, the second order inertial forces are directed up or down from the piston. In a boxer engine, because the pistons are opposite each other, these inertia forces are balanced to ensure smooth engine operation. In an in-line four-cylinder setup, all forces are directed in one direction, which causes the engine to vibrate if the balance shafts are not used.

But still, the boxer engine is not ideal, due to the fact that the pistons are not in line with each other, torque is created, which contributes to the rotation of the engine along the vertical axis.

BTW SPEAKING! If you add two cylinders to any of the designs, be it a boxer or in-line six, all the inertial forces of the torque will be compensated.

You probably thought that a boxer six would vibrate due to a group of 3 pistons, but each group of three pistons balances the vibration of the other group. If we compare the dimensions of the engines Subaru EJ20 2.0L Boxer-4 and Toyota 22R-E 2.0L Inline-4, then they are almost the same, with this configuration, the engines usually do not have a volume of more than three liters, but before they were produced much larger volume.

The largest modern inline-four is a 2.7-liter Toyota Tacoma gasoline engine.

But this does not mean that the inline four does not have its own advantages:

1. It is generally more compact, has only one cylinder head and is not as wide. This leaves more room for suspension and allows for a smaller turning radius as the car's tires have more room to turn.
2. In terms of timing, this particular inline-4 has a single overhead camshaft, but more often modern cars have two camshafts.
3. The big advantage of an inline-four is that it has only one cylinder head, one intake and one exhaust camshaft, fewer moving parts, less weight, and it's much easier to reach the cylinder block for maintenance, whether it's adjusting valves or replacing plugs with inline configuration is much easier to do.

Finally we got to the topic of engine sounds. Many people claim that boxer engines sound better, but this is not really an advantage. This sound is due to the different lengths of the tailpipes.

And since Subaru has ditched this exhaust design, the new boxer fours will sound just like the rest of the four-cylinder engines. It is of course possible to create an exhaust system with tailpipes that are of different lengths to obtain a unique exhaust sound. But this can worsen the purging of the cylinder due to unequal pulsations, and there is no particular sense in this. However, when it comes to a boxer engine, fitting different lengths of tailpipes seems attractive.

Difficulties in the repair and maintenance of boxer engines

As mentioned earlier, if you need to carry out any manipulations on the engine, you cannot do without the help of a specialist. In opposition engines, without consequences, it will only be possible to change the oil with your own hands.

One of the factors that has a significant impact on the service life is the timely and systematic decoking. This procedure cleans the combustion chamber, valves and pistons from accumulated carbon deposits. It is best to carry out this procedure in the fall or early spring. It is during this period that it will be reasonable to check the oil with its changeable.

The boxer engine is a form of a device of an internal combustion engine of a car, which has a special structure: its pistons are located at a turned angle and move in a horizontal plane towards each other and in opposite directions (from each other). Another, adjacent pair of pistons is located in one position (for example, at the top).

The interaction of the pistons inside the engine is somewhat reminiscent of a boxing round, hence the other name for the device - a boxer. The design of the mechanism involves the installation of each piston on separate journals of the crankshaft. The number of cylinders in a boxer engine can be from 2 to 12, but always even. The most popular devices are with four and six cylinders (four- and six-cylinder boxers).

There are many brands of cars on the modern automotive market, each of which adheres to its own concept of equipping cars. The development and application of boxer engines are now engaged in two companies: Subaru and Porsche. Previously, the boxer engine was installed on cars such as Alfa Romeo, Honda, Chevrolet, Volkswagen, Ferrari and others.

The first boxer diesel engine was produced by Subaru in 2008. It is a four-cylinder boxer with a capacity of 2 liters, capable of developing power up to 150 hp. Its development uses the Common Rail system.

Some models of Porsche cars use six-cylinder engines (Cayman, 911). For sports cars, eight and twelve-cylinder boxer engines with increased power have been developed. Many professionals say that only six-cylinder boxers differ from the operation of conventional engines, four- and two-cylinder ones are almost the same.

Boxer boxer - basic principles of work

In general, the operating process of the boxer boxer is similar to the operation of other internal combustion engines. The main distinguishing feature of its design is the arrangement of the cylinders. The cylinders are installed horizontally, unlike most engines. This establishes another movement of the pistons: not up and down, but from right to left and vice versa (from one end of the cylinder to the opposite).

The original development of the horizontal boxer was not Subaru's, as many tend to think. Motors of this type have already been used earlier on Ikarus passenger buses, as well as on motorcycles (both domestic "Dnepr, MT" and foreign-made "enduro-tourist BMW R1200GS and others"). In addition, such engines have long been used in military vehicles, in particular, in domestic tanks.

Naturally, such an engine structure has its pros and cons. Let's consider them in more detail.

Benefits of a boxer boxer

Pictured is a Porsche boxer engine

The main advantages of an engine with horizontally positioned cylinders include:

1. Promotes a shift in the center of gravity. The mass is distributed around the axle, which greatly improves the handling of the machine. For many, this factor is decisive when choosing an engine and a car, this is especially true for Russian roads.
2. No vibration during operation. Engines with a standard structure and vertically arranged cylinders vibrate during operation, transmitting waves to the entire structure, which is not very comfortable for the driver.
3. Long work. The resource of the boxer boxer installed in Subaru is so great that it allows you to operate the car for a long time (it is enough for more than a million kilometers).

Disadvantages of a boxer engine

Pictured is a boxer engine Subaru Outback 2015

Despite the significant advantages, an engine of this type has significant disadvantages, which the developers have not yet gotten rid of:

1. Requires expensive maintenance. Often, ordinary engine repairs are carried out independently or in car dealerships for a small amount. However, in the case of a boxer boxer, this is not possible. Its design is too complicated, so it is better to entrust the installation to professionals. Moreover, for such services you will have to pay a decent amount of money.
2. The second drawback follows from the first drawback - even if there are sufficient funds for servicing this type of engine, it may be difficult to find a qualified specialist who can provide quality service.
3. The complexity of the boxer's device increases the cost of its component parts, which creates additional costs for repairs.
4. Increased consumption of automotive oil. A conventional engine consumes no more than three hundred grams of oil during its operation, and an opposed one is much more.

Thus, all the disadvantages of the device primarily lie in the high cost of its maintenance. This can be a significant factor for many car owners. However, according to representatives of the car companies Subaru and Porsche, the quality of its work is worth the money spent on maintenance.

Subaru does not intend to change the boxer engines to standard ones, as its representatives tend to believe that this will be a big step back. The high cost of engine maintenance does not affect the level of sales of cars of this brand, since the cars have proven themselves exclusively from the positive side.