The internal combustion engine (ICE) has come a long way since the dawn of industry. Its design features, dimensions, and weight have changed. As a result, today there are many types of it, which we will consider. However, the definition of ICE remains unchanged – it is a type of thermal motor, which converts the energy of fuel mixture explosion into mechanical force. In the combustion chamber of the motor, the mixture explodes and transfers its energy to the piston group, setting it in motion. Piston motors are the most common in the automotive world, and we will talk about them.
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Division of internal combustion engines by type of fuel
Designers in the development of engines take into account many factors: the different number of strokes, the arrangement of cylinders, the type of mixture. According to the type of fuel, the engine can be gasoline, diesel, and hybrid – says engineer Kirill Yurovskiy.
Gasoline engine
This type of engine is the most common among motor vehicles. It is distinguished by simplicity of design, availability, and low cost of parts for repair.
Fuel is supplied to the gasoline engine in two ways. One is the good old carburetor, it is a special mechanism in which gasoline and air are mixed in certain proportions. The path of this mixture then travels to the intake manifold. For many decades, this type of fuel supply was the most common, it was distinguished by a simple design solution and the ability to make quick repairs.
But time is of the essence, and old solutions are giving way to new ones. The term of the carburetor has come to an end, because even before, everyone was well aware of its shortcomings, among which are instability in operation, reaction to temperature changes, environmental damage (its limit is Euro-3), difficulties in adjustment.
Injector
The injector power system was a new solution, and the carburetor had to give way. The injector system is subdivided into distributed fuel injection and mono-injection. The first is more common in internal combustion engines. Fuel is routed from the tank to the ramp, distributed by injectors to the intake manifold and then brought to each cylinder separately. It turns out that each section has its own injector.
There is another design, in which the injectors immediately supply gasoline to the combustion chamber. Such an ICE is more accurate in terms of fuel mixture distribution, increasing the efficiency of the motor to maximum values.
All the disadvantages of the carburetor in the injector system turn into pluses: stable operation, high environmental friendliness and efficiency, increased power, less susceptible to temperature differences. All these advantages are suitable for residents of megacities and large cities with numerous technical service stations, official representative offices of the factories-manufacturers. The driver can count on proper diagnostics and repair at any time. But if difficulties with the injector engine have occurred on the highway, away from populated areas, then, unlike the carburetor, the repair by your own forces is no longer possible. Hence the disadvantages of the injector – in addition to the difficulties with the repair, the high cost of replacing parts, the quality of gasoline is not less than AI-92.
Diesel engine
The main difference between the diesel and gasoline engines is the way the ignition mixture is created. In the gasoline engine, it enters through the intake manifold, while in the diesel engine it enters directly into the combustion chamber. The ignition occurs differently as well. First, the cylinder “draws in” air. Then the piston rapidly compresses and the temperature inside rises to 800 degrees, the fuel is pressurized and ignited. The temperature immediately rises to 2300 degrees. An important point – the speed of fuel injection affects the quality of the mixture, at a low speed the fuel does not evaporate completely. The diesel engine has no ignition system. The disadvantages of the diesel engine have already been noted by many automotive experts. Among them are difficulties in cold starting, high weight, increased vibration.
High pressure fuel pump
So, the most important difference between a diesel engine and a gasoline engine is in the fuel supply system. In the diesel engine an important role is assigned to the high-pressure fuel pump (HPP). Its work is as follows: the fuel from the fuel tank by necessary parts through separate lines goes to the injectors and then separately in each chamber.
High-pressure fuel pumps can be distributive and multi-plunger in-line, which are very rare in modern cars. Adjusting the fuel pump is not an easy task, and without special tools and instructions to perform it is not easy. Nevertheless, many companies strive for design solutions that simplify this task, in particular the Volkswagen Group, which produces Audi, Skoda and Porsche cars.
Rotary engine (RE, Wankel engine)
First of all, the rotary engine differs from previous internal combustion engines structurally, plus it runs at higher rpm. The RE was invented in the 1960s by two German engineers Walter Freude and Felix Wankel. The peculiarity of this type of engine is the location of the rotor directly in a specially shaped cylinder.
The rotary engine has no crankshaft and connecting rods, so the design looks simpler. Hence the first advantage – a small number of parts, in a conventional four-cylinder motor it comes to five dozen. The rotary engine has more power, for example, the 1.3-liter motor can produce up to 240 horsepower. In addition, this type of engine takes up much less space due to its compactness.
The disadvantages are also significant: the resource RE is limited to 70-80 thousand km. mileage, increased fuel consumption, low environmental parameters and the high cost of production and repair.
Hybrid engine
The hybrid engine gained popularity later than its counterparts, and it came to the automotive industry from railway transport. However, the first experiments with a hybrid engine were conducted by Ferdinand Porsche at the beginning of the last century. The main advantage of the hybrid is its environmental friendliness. Today, almost every self-respecting automaker produces at least one model of this type. The very name “hybrid” implies the interaction of two types of engine – gasoline and electric.
The hybrid engine is controlled by electronics, it makes a choice in favor of gasoline or electricity depending on the road situation. In the city electric propulsion is used more often, which leads to great fuel economy, but on the highway the fuel motor comes into play, since the battery is quickly discharged. It should be noted that while using the gasoline engine, the electric motor is recharged. The hybrid engine can run at full power, using its two “halves”, it happens in conditions of increased loads.
So, the obvious advantages: environmental friendliness and efficiency, the absence of noise, power at the level of other motors. At the same time, there are disadvantages: due to the complex design, repairs cost a pretty penny, and short battery life. If for the city this type of engine is suitable as no other, for the countryside in our realities its benefit is practically absent.
Types of internal combustion engines
In addition to the types of fuel, internal combustion engines differ in the type of cylinder arrangement. Of these, we can distinguish the most popular: in-line, V-shaped and opposed.
In-line engine
In-line engines are the classics of automobile construction, it is them that belongs to the primacy of appearance. According to the name, the cylinders are arranged in one row and drive a single crankshaft. The cylinder head is the same for all combustion chambers. There is a different number of cylinders, up to ten, but such variants are very rare because of the complexity of production. The most common are one-, two-, four- and six-cylinder engines.
In-line engines do not take up much space in the under-hood, easy to service, but not perfectly balanced. However, this disadvantage cannot be called significant, so this type of engine is very popular with both manufacturers and car owners.
V-engine
The V-type engine is similar to the inline engine, but the cylinders in it are arranged differently – against each other, the engine is more compact. It has two cylinder heads, a different gas distribution mechanism and fuel supply from the inline engine. The letter “V” is in the name for a reason, as it indicates that the cylinders are located at an angle to each other, and the angle is important. The angle varies, but the best option is considered to be 45, 60 and 90 degrees.
Despite the complexity of the design, rather high vibration load and costly repairs, V-shaped ones are popular in various industries. Some automakers are involved in the production of these engines exclusively.
Opposite engine
This type of engine is related to the V-shaped engine, as the cylinders here are arranged at a 180-degree angle, in other words, against each other. There are also two camshafts and the timing mechanism is arranged vertically. Such arrangement deprives the opposition engine of unnecessary vibrations, it runs more smoothly. The center of gravity is lowered, consequently the handling of the vehicle is improved. Operating life of such an engine is up to 500,000 km before overhaul.
Opposite engines are of two kinds: with counter-movement of pistons and the so-called “boxer”, when the pistons are located in front of each other as boxers in the ring. When one piston is at the bottom, its “partner” reaches the highest point and vice versa. Thus, a kind of “exchange of blows” takes place.
The disadvantages are high cost and complexity of service. Besides, not every service station can find a mechanic experienced in opposites engines.
Two and Four Stroke Engines
Today, two-stroke engines can be talked about as a retro element. They were used more often in the old days, but the requirements for cars have increased since then, primarily in terms of ecology. Cars with two-stroke engines consume a lot of gasoline and oil and are extremely environmentally unfriendly. At the same time the construction of a two-stroke engine is very simple (no gas distribution mechanism) and it has a small weight.
The two-stroke engines have said goodbye to automobiles, but they have not disappeared from everyday life. They can be easily found in lawn mowers, snow blowers, circular saws and other mechanisms where uniform revolutions are required.
Running a four-stroke engine
As you understand, the difference between these two engines is in the number of strokes of the working cycle Four-stroke engines continue to be used in cars, their work is uniform, they consume less gasoline, are easy to maintain, and their environmental friendliness is higher. Operation of a four-stroke engine is divided into four stages, or strokes.
At the first stage, the combustion chamber is filled with mixture. The piston at this time moves to the lowest point, and the intake valve opens. The fuel mixture enters the combustion chamber, the piston reaches the lowest point and the valve closes.
In the second stage, the fuel mixture is compressed: the piston goes back up and the fuel mixture explodes when it reaches the highest point.
In the third stage, the fuel mixture is ignited and the force of the explosion pushes the piston downwards, the mechanism works.
In the fourth, the gas expands and the cylinder is cleared. The piston is lifted up by the crankshaft, the exhaust valve is opened, and the burnt gas flows into the exhaust manifold. Then there is a return to the first cycle.
In our review we did not touch such a type of engine as electric, which becomes more and more popular among motorists, but structurally it is cardinally different from all listed, it has completely different requirements, and the story about it deserves a separate article.
