After invention of the first combustion engine, the question of its upgrading and power improvement occurred. The first engine was one-cylinder. That’s why people began finding solution in its power upgrading through increasing the number of its cylinders. But its further development wasn’t so apparent, because there are different ways to place those cylinders: horizontally, vertically, one after one in a row or at an angle.
That’s why position of cylinders was called boxer engine. Such engine was made to move car gravity centre as lower as possible and reduce vibration.
• How is boxer engine arranged and its operation principle
• Types of opposite engines
• Opposed boxer
• OPOC engine – old ideas revival
• Compliances that may occur during opposed engine repair
• Boxer engine repair
• Pros and cons of opposed engine.
How is boxer engine arranged and its operation principle
Special feature of opposed engine is specific position of its pistons, which are placed at an angle of 180°. As a result, such engine runs more smoothly, than others. This type of engine is mostly used by such car manufacturers as Volkswagen and Subaru.
Due to horizontal position of cylinders, the vibration is reduced and smooth motion is provided. This might be caused by piston movement in opposite directions, while car is on the move. That’s how mutual neutralization of vibration is done. So, the power of engine grows smoothly without snaps. Also engine doesn’t wear out fast.
Practical design of boxer engine has a good influence on car stability and driving. Horizontal position makes pistons closer to running gear. Due to this, the gravity centre is low.
Types of opposed engines
Even such technical solution as placing cylinders horizontally in front one another can be performed in several ways. While opposed engine is working, its pistons can move differently. There are several types of opposed engines.
While such engine is operating, its pistons are placed relatively to each other at specific distance. Each piston operates in its cylinder: if one of them is positioned at maximum distance from engine centerline, the nearby piston takes the same position. This operational type resembles movement of two boxers. Because of that it was called boxer. Such type of opposed engine is often used for Subaru cars.
OPOC engine – old ideas revival
The OPOC engine has different type of construction than opposed boxer engine. Nowadays these engines are developed anew.
This type of opposed engine is two-stroke. One cylinder has two pistons, which are fixed on one crankshaft. One piston is meant for mixture injection, another one – for combustion gases release. There are integral cylinder head and valve operating system in such type of construction. Besides, the fact that pistons work on one crankshaft is considered as advantage of such opposed engine.
All these peculiarities affected its weight. It became lighter. Due to this, range of its use significantly increased. Another advantage of this type of opposed engine that it can be as gasoline, so diesel.
You just need to remember that as any two-stroke engine it needs cylinders drain. Electric motor powered from external source is needed for this. While opposed engine works, electric motor turns off and air feeder turns into turbocharger.
Observing construction of this boxer engine, we must point its pros: increased efficiency, which is reached by expanding gas pressing on two pistons instead of compression chambers wall and increased shaft stress. Along with that, each piston passes less distance, because of that force of friction is reduced.
Observing other advantages of this type of opposed engine, which is produced as diesel engine:
• This engine type is approximately 30-50% lighter, than ordinary turbo diesel.
• This boxer engine has 50% less components, than ordinary diesel engine.
• Consumes less of place under hood.
• Efficiency is another advantage of such type of engine. But you should know that this opposed engine type is raw. That means that all advantages mentioned above are just expectations of manufacturers.
Compliances that may occur during opposed engine repair
We must mention that all advantages of opposed engine show up mostly on six-cylinder engines. But four- or two-cylinder ones are mostly no different from ordinary power packs. Main disadvantage of opposed engine is that it is hard to maintain. Due to horizontal position of its pistons, it consumes much place in engine bay.
The only thing the driver can do to maintain the car with such engine is to replace oil. All other procedures require special devices. That’s why they are performed at service stations. For example, even the simplest task, which is plug replacement, must be performed by specialist, because rookie can damage cylinder head. Like any other engine, the boxer engine must be repaired at service stations.
Boxer engine repair
In different times of automobile history developers used opposed engine trying to reach the advantages it should have. But nowadays this type of engines is mostly used by Subaru.
Worth to mention that boxer engine provides following advantages for your car:
• Your car will have low gravity center, which will increase its stability.
• Boxer engine reduces noise and vibration, due to pistons movement towards each other. So, opposed engine is more quiet, than other types of engines.
• Substantial resource, which reaches approximately million kilometers while correct exploitation of engine.
If there are pros of such engine, then there also must be some cons, which are mentioned below:
• It is very hard to repair.
• The construction of such engine is very complicated, that means its cost is high.
• The cost of maintenance service is high. And the maintenance itself is quite costly and requires highly qualified specialists.
• Boxer engines consumes much oil while use.
Though, despite of all disadvantages, mentioned above, opposed engines are installed on some car models. Car manufacturers think over all pros and cons, before installing this type of engine.
Horizontal position of cylinders for combustion engine is one of various construction types. But despite of it, these engines have many opportunities and perspectives in being used for cars.