How many kinds of car engines are there? What is the difference? What kind of performance is good!

There are many kinds, which can be divided into several types according to different classification methods: gasoline engine, diesel engine, natural gas engine, liquefied petroleum gas engine and so on according to the fuel used. The number of working cycle strokes is divided into four-stroke (four-stroke) engine and two-stroke (two-stroke) engine; According to the number of cylinders, it is divided into single cylinder, double cylinder and multi-cylinder (more than three cylinders) engines; According to the cooling mode, it is divided into water cooling and air cooling; According to the arrangement, it can be divided into in-line L-type H-type W-type V-type arrangement and so on.

Classification by structure

Automobile engines usually have more than three cylinders, and the main classification method of automobile engines is based on the layout and arrangement of cylinders. There are generally in-line, V-type, W-type and horizontally opposed.

In-line engine, all cylinders are arranged side by side at the same angle on a plane. Its advantages are that the cylinder block and crankshaft are very simple in structure, and the cylinder head is used, so the manufacturing cost is low and the size is compact. In-line engine has high stability, good low-speed torque characteristics and low fuel consumption, but it has the disadvantage of low power and is not suitable for engines with more than 6 cylinders. In-line engines are widely used in domestic cars, and almost all domestic cars and four-cylinder engines below the mid-range are in-line engines.

Classic example: BMW has always been a staunch supporter of inline engines, and BMW's L6 (inline six-cylinder) engine can be regarded as the ultimate in inline engines in terms of technical content, cylinder number and performance. BMW's top model, the new 7-Series sedan, still has an L6 engine version.

V-type engine, all cylinders are divided into two groups, and adjacent cylinders are arranged together at a certain included angle, so that the two groups of cylinders form a plane with an included angle. Seen from the side, the cylinders are V-shaped, so it is called V-type engine.

V-type engine is small in height and length, which is convenient to be arranged on the car. In particular, modern cars pay more attention to aerodynamics. The smaller the windward side of the car, the better, and the lower the hood. In addition, if the engine length is shortened, more space can be left for the cab. Because the cylinders have been staggered, it is convenient to increase the displacement and power by increasing the cylinder diameter, which is suitable for a higher number of cylinders. In addition, the V-type engine cylinders are arranged in opposite directions, which can also offset part of the vibration and make the engine run more smoothly.

The disadvantage of V-type engine is that it must use two cylinder heads, which is complicated in structure and high in cost. In addition, after its width is increased, the space on both sides of the engine is small, and it is not easy to arrange other equipment.

At present, V-type six-cylinder engines are used in many medium and high-end vehicles in China, such as Regal, Passat and Audi A6.

Classic example: European luxury cars often adopt V-engine design with more than 8 cylinders. For example, Rolls-Royce cars and Mercedes-Benz S600 cars are all V 12 engines. At present, the V engine can reach 16 cylinder at the highest, and the displacement is above 10 liter.

W-type engine, W-type engine is the exclusive engine technology of German Volkswagen. The V-engine is formed by staggering the cylinders on each side by a small angle (for example, the small angle of Passat W8 is 15 degrees). In other words, the cylinder arrangement of W-type engine consists of two small V-shapes to form a big V-shape. Strictly speaking, the W engine should also be a variant of the V engine.

Compared with V-type engine, W-type engine can make the engine shorter and the crankshaft shorter, which can save the space occupied by the engine and reduce the weight, but its width is larger and the engine room is fuller.

The biggest problem of W engine is that the engine is divided into two parts from a whole, which will inevitably produce great vibration when running. In order to solve this problem, Volkswagen designed two counter-rotating balance shafts on the W engine, so that the vibration of the two parts can cancel each other internally.

Classic example: Phaeton, Volkswagen's flagship model, didn't have a two-cylinder engine before, but compared with S600, Volkswagen's new engine W 12 completely changed this disadvantage. Volkswagen's other two luxury cars, Bentley GT and Audi flagship A8L6.0, will use the engine W 12.

Horizontally opposed engine, if the inline engine is regarded as a V-type engine with an included angle of 0 degrees, when the included angle of two rows of cylinders is expanded to 180 degrees and the cylinders are arranged horizontally, it is horizontally opposed engine.

Horizontally opposed engine's greatest advantage is its low center of gravity. Because its cylinder is "flat", it reduces the center of gravity of the car, and at the same time, it can make the front of the car design flat and low. These factors can enhance the driving stability of the car. In addition, the layout of horizontally opposed cylinders is a symmetrical and stable structure, which makes the running smoothness of the engine better than that of the V-type engine, and the power loss during operation is minimal.

Classic example: horizontally opposed engine is one of the signature technologies of Japanese Fuji cars, and the Fuji WRX-STi model adopted by horizontally opposed engine is a legendary model in the field of world rally, and it is also the dream favorite of the world racing family.

Rotor engine, the traditional engine drives the car forward through the reciprocating motion of the piston in the cylinder. The engine and the cylinder itself are relatively static, while the rotor engine is a triangular piston rotor engine, which uses the rotating motion of the triangular rotor to control compression and emission. The advantages of rotary engine are obvious. It is small in size, light in weight, high in power and extremely low in vibration and noise. However, due to the complexity of rotor technology, its manufacturing cost is extremely high and its durability is lower than that of traditional engines.

Classic example: Up to now, only one manufacturer, Mazda, has applied rotor engine technology to market products. At present, Mazda's famous RX-8 sports car is the latest successor of rotary engine technology.

Divided by engine layout

According to the layout of the engine on the car body, it can also be divided into three types: front engine, middle engine and rear engine.

At present, most of the models that can be seen in the domestic automobile market are front engines, that is, the engine is located in front of the front axle. The advantage of the front engine is that it simplifies the structure of the transmission and drive axle of the automobile. Especially for the absolutely mainstream front-wheel drive vehicles, the engine directly transmits power to the front wheels, omitting the long transmission shaft, which not only reduces the power transmission loss, but also greatly reduces the complexity and failure rate of the power transmission mechanism. Because the engine is placed in front of the driver, it can protect the driver from impact in a frontal collision, thus improving the safety of the car.

Corresponding to the front engine is the rear engine, which often corresponds to some high-horsepower models with rear-wheel drive. The typical model is Porsche's 9 1 1 series sports car. Another layout is that the engine is located between the front and rear axles of the car. For some cars that are extremely pursuing performance, it is an ideal way to center the engine, because the position of the engine is just close to the center of gravity of the car, rather than the weight is too concentrated in the front or rear of the car to achieve the best weight ratio, which will greatly improve the handling and driving stability of the car. Many classic sports cars, including Ferrari and Lamborghini, adopt a mid-engine layout.

Classification by fuel

Diesel engine and gasoline engine

According to the fuel used, automobile engines can be divided into gasoline engines and diesel engines.

Compared with diesel oil, gasoline has a lower boiling point and is easy to vaporize. The gasoline engine compresses the cylinder, vaporizes the inhaled gasoline and mixes it with the air in the cylinder to form a combustible mixture. Finally, the spark plug discharges to ignite gas to push the cylinder piston to do work. Diesel is characterized by low spontaneous combustion temperature, so diesel engines do not need ignition devices such as spark plugs. It uses compressed air to raise the air temperature, so that the air temperature exceeds the diesel spontaneous combustion test. At this time, diesel, diesel spray and air are simultaneously injected and ignited. Generally speaking, compared with two kinds of engines, gasoline engines need to control the injection quantity, injection time and ignition time of gasoline very accurately, so the structure is often more complex and precise than that of diesel engines, and the cylinder pressure of diesel engines is greater than that of gasoline engines, so the structural strength and stiffness of materials are required higher.

In terms of performance, the advantages of gasoline engine are high maximum power and speed, quiet and stable operation and low emission, while the advantages of diesel engine are high combustion efficiency, low fuel consumption, low-speed torque and maximum torque far exceeding those of gasoline engine. Reflected in the driving experience, people will find that diesel vehicles start very fast on mountain roads and ramps, and have full stamina, and then they are not the same as gasoline engines in the middle and late stages of acceleration and maximum speed. The traditional diesel engine in China has always given people the impression of large volume, loud noise and serious pollution, so domestic cars basically use gasoline engines. However, in recent years, well-known foreign automobile manufacturers began to introduce some latest diesel engine technologies into China, which greatly improved the prejudice of Chinese people against diesel engines. For example, Bora, a TDI diesel engine just launched by FAW-Volkswagen, is not inferior to gasoline engines in terms of environmental protection, power and ride comfort, and it also has the unique large torque and ultra-low fuel consumption of diesel engines, so the market prospect is very promising.

The cylinders of the engine are divided into in-line, V-type, horizontally opposed and newly emerging W-type.

In-line cylinders are also called parallel cylinders, usually 4 or 6 cylinders.

Advantages: stability, low cost, simple structure, good running balance and small volume.

Disadvantages: When the displacement and the number of cylinders increase, the length of the engine will increase greatly.

Four-cylinder inline engines are generally widely used in engines with displacement less than 2.2 liters.

6-cylinder inline engine, the most famous example is BMW's M3. The main purpose of BMW's choice of 6-cylinder inline engine is to facilitate counterweight and stability. Although the inline engine is relatively simple, it is definitely not synonymous with bad.

V engine

Common V engines are V6, V8, V 10 and V 12. There are V3, V5, V 16 (not to be confused with the number of valves represented by some in-line engines). As the name implies, V represents the V-shaped arrangement of engine cylinders, generally 90 degrees, which can offset the vibration during operation and be more stable. There are 75 degrees and 72 degrees. Renault even used a wide-angle V 10 engine of more than 90 degrees.

Advantages: stable operation (suitable for V6, V8 and V 12) and space saving.

Disadvantages: the structure is complex, which is not conducive to maintenance and high cost. At the same time, V3 and V5, including V 10, are not very stable in structure and displacement, especially the V 10 3L engine, that is, the F 1 engine, which requires a lot of energy and money to ensure its stability.

Representative models: Audi A6, Ferrari 360, Porsche carrear GT and Mercedes S600. Use V6, V8, V 10 and V 12 engines respectively. V3 mainly appears on some motorcycles, and V5 is said to be used in the previous generation of Volkswagen Golf. V 16 can be found in some luxury classic cars.

horizontally opposed engine

This is also a V-type engine, except that the included angle of V becomes 180 degrees, usually 4 or 6 cylinders.

Advantages: low center of gravity (nonsense, it is 180 degrees, can it be lower than it), easy to control and balance.

Disadvantages: the cost is still high and the engine is too wide.

Horizontally opposed engine's most famous application is the famous 9 1 1.

W engine

This kind of engine may be a bit strange, but it's nothing. "V+V=VV" is just W, just two V engines.

The design idea of W-type engine is to use two V-type engines to form a V-type engine.

Advantages: the structure is more compact, more cylinders can be accommodated, and the displacement is larger.

The disadvantage is that the structure is too complicated! The balance of operation is not good.

Because of the patent, this kind of engine can only be seen in a few cars such as Volkswagen and Audi. European Volkswagen Golf, European Volkswagen Passat and Audi A8 are equipped with W6, W8 and W 12 engines respectively.

Epicycloidal engine

Rotor engine, also known as triangle piston rotor engine, is a special piston engine. The piston of the rotor is a convex arc triangle. When the rotor rotates in the cylinder of the epicyclic line, the three vertices of the arc triangle keep in contact with the cylinder wall, thus forming three mutually isolated working chambers between the arc surface of the rotor and the cylinder wall. The volumes of these three working chambers change periodically with the rotation of the rotor. Every time the rotor rotates, each working chamber can complete a four-stroke process, corresponding to the four strokes of the piston reciprocating engine, thus forming a complete working cycle.