Why the boxer engine is good. The principle of operation of the boxer engine. OPOC, reviving old ideas

They differ from each other not only in the type of fuel consumed, but also in design features. For example, there is a great variety in the arrangement of the cylinders. Each option has its own strengths and weaknesses. In this case, the pros and cons of a boxer engine will be considered.

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What are the features of a boxer engine

In reciprocating internal combustion engines (and there are also rotary ones), the placement of cylinders can be different in relation to each other: at an acute angle, in one row, star-shaped, and so on. In the case of an opposed cylinder, the cylinders are in the same plane and are placed opposite each other at an angle of 180 degrees. Unlike many in-line engines, the opposed unit often has two and also vertical distribution. There are several types of boxer engines. Among them, the most famous are:

• Boxer. It differs in that the pistons, located in front of each other, move like boxers in the ring. That is, when one of them is at the extreme upper point, the second takes the extreme lower position. They are all the time equally distant from one another;
• OPOS - Opposed Piston Opposed Cylinder. The principle of operation in this case is that the pistons are in pairs in one cylinder (upper and lower piston). They move towards each other by rotating the crankshaft.
• 5 THF. This is a Soviet-made two-stroke tank engine that was used on the T-64 and T-72 tanks. An interesting feature of this unit is its multi-fuel capacity. The main fuel for him is diesel fuel. However, using a special switch on the high-pressure fuel pump, it was possible to start the operation on gasoline or on a mixture of gasoline with kerosene and diesel fuel, and the engine could also run on jet fuel. True, it was also required to correct the ignition angle (injection timing).

Many companies were actively involved in the development of power units. For example, Volkswagen has been paying attention to this type of unit since the mid-30s of the last century. These were not just experiments, but the desire to develop our own boxer engine, to reduce the level of vibrations that arise during the operation of a traditional V-shaped or in-line engine, etc. By the way, Volkswagen engineers applied their development to the legendary Volkswagen Beetle. And since the 60s, boxer engines have been actively used by the Japanese company Subaru, which was developing in parallel with the Germans.

Benefits of an opposed internal combustion engine

By and large, the operation of a boxer engine does not differ from the principle of operation of units of other designs. However, this arrangement of cylinders has certain advantages as well as disadvantages.

• The most noticeable advantage of the considered power plants is the almost complete absence of vibration during operation. This effect is achieved through arrangements that balance each other. This not only adds comfort, but also significantly increases the service life. From here comes the second "plus";
• Impressive flat engine life. There is evidence that quite often the mileage before the first overhaul was at least 500 thousand kilometers. Of course, the driving style makes its own significant adjustments. And, nevertheless, the turnaround time is quite long. However, all the time you can find the assertions of experts and motorists that 800-900 thousand before the first is nothing more than a beautiful fairy tale;
• The motors of the design considered in this article provide cars with a low center of gravity. This quality is especially appreciated in powerful sports cars. Indeed, passing bends at high speeds, it is very important to maintain stability;
• Also, one cannot fail to mention the saving of space under the hood. Although this point will seem controversial to many, because winning in height, you need to make the hood wider or longer.

These are, perhaps, all the essential advantages of opposites. Now we need to consider the disadvantages, which, unfortunately, are somewhat larger.

The main differences, as well as the advantages and disadvantages of 8-valve engines compared to 16-valve engines. Which power unit is better to choose.

I continue to talk about internal combustion engines. Moreover, I like to talk about engines that are not understandable for a common man in the street, for example, from Volkswagen. Today, no less interesting engine, which is also installed on a narrow range of cars. It's about a boxer engine. Basically, now such units are used by Subaru, as well as the Volkswagen Group corporation, in their cars. So what kind of engine is this? Read on ...

- an internal combustion engine in which the pistons are located horizontally (or at an angle of 180 degrees), in contrast to an in-line internal combustion engine, in which the pistons are located vertically. That is, in simple words, it can be called a horizontal motor. The pistons of such a unit are located - two on the right and two on the left. During operation, the pistons converge and diverge horizontally. Since the pistons are separated, each group of pistons has (two on the right and two on the left), two camshafts. That is, on the right, there are two camshafts - 8 valves and the same ones on the left. Gas distribution mechanisms in a boxer engine (camshafts and valves) are located vertically, in contrast to a classic in-line engine, where they are located horizontally. Here's a small diagram.

The first boxer engines appeared back in 1938, they were installed on Volkswagen Käfer cars (Volkswagen Beetle was used in chic application). It was Volkswagen who first developed the horizontally opposed engine. Some modern cars belonging to the Volkswagen Group are now equipped with such engines (for example, Porsche 997, Porsche Boxster, etc.). Also in the 1940s, SUBARU was independently developing its engine. To this day, Subaru equips its cars with horizontally-opposed engines.

Why was the boxer engine created?

Was designed to lower the vehicle's center of gravity. Probably everyone knows that the lower the center of gravity, the better the driving characteristics of the car, the roll of the car will be less when cornering.

Advantages of a boxer engine

1) As I wrote above, it was created to lower the center of gravity of the car, which has a very good effect on driving performance.

2) Another plus is the arrangement of the cylinders. When moving towards each other in a horizontal plane, extraneous vibrations are much more damped. Therefore, this engine is considered to be much quieter than its in-line or V-shaped counterparts.

3) Also from the pros, I would like to note the large resource of this type of engine. For example, SUBARU engines have a resource of about 1,000,000 kilometers, with proper use and timely replacement of consumables.

Cons of a boxer engine

1) The first and most significant disadvantage is the difficult repair of such an engine.

2) The complex structure, which means the expensive price of this engine.

3) Complicated maintenance.

This unit is durable, but complex in structure. Its dynamic performance is similar to that of an in-line gasoline engine. Power and consumption. And now a short video.

SUBARU boxer engine video

Let me finish with this, I think it became a little clear what it is and how it works.

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

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

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

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.

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.

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 novelty, presented in 2002, aroused great curiosity. The pros and cons of the Subaru boxer engine are assessed by almost every motorist, even if he is not going to change his iron horse yet or prefers models from other manufacturers.

Diesel fans are also showing interest, although the opposites are produced exclusively in the petrol interpretation - the promised advantages are tempting for everyone. Those who, by definition, love Subaru products, want to know what they have to deal with, since the concern intends to equip its models with only such engines in the near future.

The pros and cons of a Subaru boxer engine are naturally determined by the peculiarities of its structure. The principle of its operation remains the same, the engine has not gone anywhere from the idea of ​​internal combustion. But the design solution is original. And opposites are used only on Subaru and Porsche cars. Although not so long ago they were equipped with Honda, Alfa Romeo, Chevrolet, Ferrari, Volkswagen and a number of others.

What is a boxer engine?

In classic motors, the cylinders have a vertical orientation and move, respectively, in the direction: up - down. In opposites, they are located horizontally, as a result of which the pistons move left - right. Since this movement strongly resembles a fight in the ring, this type of engine is popularly nicknamed "boxer".

It is interesting that the idea is not very original, but rather forgotten. Similar motors were on board the Ikarus and Soviet motorcycles like the Dnieper, which had gone into oblivion, and were on some models of domestic tanks. Of course, Subaru developed a more perfect mechanism, but still they did not start from scratch at all.

Advantageous sides of the opposition

Subaru also brings small dimensions to them, but we have already figured it out, so we cannot agree with the opinion of the company. The main advantages are given precisely by the horizontal orientation.

• Center of gravity shift... First, it is underestimated compared to in-line motors. Secondly, it is distributed along the axis. This gives better handling and stability;
• Reduced vibration... Conventional, even high-quality engines, to a certain extent transmit vibration waves to the body and to the interior. In opposites, the vibration of one piston is smoothed out and leveled by the oncoming movement of the second;
• Great resource... Boxers are theoretically rated for a million kilometers. Is this so - time will tell, but I want to believe;
• Enhanced security... And it has been proven by crash tests. In a head-on collision, conventional engines often go into the salon, breaking the front riders' legs. The boxer engine under a direct impact is displaced under the bottom, reducing the likelihood of death.

Flaws

Perhaps it was they who led to the low prevalence of boxer engines. After all, many companies have gradually abandoned their use. And if in sports cars opposites are still found, then in, so to speak, everyday ones are quite rare.

• Engine self-maintenance is virtually zero... The complexity of its configuration leads to the fact that the owner can only change the oil himself. Even in order to replace or clean the candles, you will have to go to the service station. Anyone who dares to do this on their own has a high probability of seriously damaging the cylinder head.
• A flat-engine car is much more expensive to maintain than an in-line car. All auto works are estimated by masters higher, parts in price are 2-5 times higher than those for “rowers”.
• The opposed engine requires a catastrophic amount of oil. And if we reduce all the disadvantages to a single denominator, then we can say that they are too high monetary costs. That does not prevent people who have appreciated all the pros and cons of the Subaru boxer engine, to give preference to such models and still strive for the desired purchase.