Currently, there are several options for power units, depending on the layout and number of cylinders. The V8 engine belongs to the top-level engines for passenger cars, as it is equipped with sports and elite models. Therefore, they are not very common, but in demand.
The V8 engine is a V8 engine with two rows of four cylinders and a common crankshaft.
Prerequisites for Creation
At the beginning of the last century there was no direct connection between the engine size and the number of cylinders. However, over time, factors such as increased RPM and power, as well as a drive to reduce costs, led to the introduction of the mid-cylinder. In addition, there was such a thing as liter power. Thus, they related the power of the engine to the number of cylinders. That is, each cylinder has a certain volume, and a certain power is removed from a specific volume value. Moreover, these characteristics are optimized, that is, go beyond them whenserial production is unprofitable. Thus, small mass models began to be equipped with small displacement engines with a small number of cylinders, and in order to achieve high power it was necessary to create multi-cylinder power units of a larger volume.
The first V8 engine went into production in 1904. It was developed two years earlier by Léon Levasseur. However, it was not used for cars, but was installed on aircraft and small vessels.
The first 3536cc V8 car engine3 was produced by Rolls-Royce. However, she only built 3 cars equipped with it.
In 1910 the 7773 cm3 V8 was introduced by manufacturer De Dion-Bouton. And although there were also very few cars equipped with it, in 1912 it was presented in New York, causing great interest. After that, American manufacturers took up the creation of such engines.
The first relatively mass-produced car with a V8 engine was Cadillac in 1914. It was a 5429 cm lower valve engine3. There is an opinion that its design was copied from the French power unit mentioned above. Approximately 13,000 vehicles equipped with it were produced in the first year.
After 2 years, Oldsmobile introduced its version of the 4L V8.
In 1917, Chevrolet also launched the 4.7L V8, however, the following year, the manufacturer became part of GM, of which the two firms mentioned above were also subdivisions. However, Chevrolet, unlike them, focused on the production of economicalcars that were supposed to be equipped with simpler engines, so the V8 production was stopped.
All the engines discussed above were installed on expensive models. For the first time, they were transferred to the mass segment by Ford in 1932 on the Model 18. Moreover, this power unit had a significant technical innovation. It was equipped with a cast iron cylinder block, although until then the production of such parts was considered by some to be technically impossible, so the cylinders were separated from the crankcase, which made them more difficult and expensive to manufacture. To create a one-piece part, it was necessary to improve the casting technology. The new power unit was named Flathead. It was produced until 1954
In the US, V8 engines became especially widespread in the 30s. They became so popular that all classes of passenger cars, except for the subcompact, were equipped with such power units. And cars with a V8 engine by the end of the 1970s accounted for 80% of all produced in the United States. Therefore, many of the terms associated with these powertrains are of American origin, and V8 is still associated with American cars for many.
In Europe, these engines have not gained such popularity. So, in the first half of the last century, only piece-produced elite models were equipped with them. Only in the 50s did the first serial eight-cylinder engines or cars with a V8 engine begin to appear. And then some of the latter were equipped with American-made power units.
At the beginning of the pastcentury, there were very unusual engine layouts for modern times, for example, seven-cylinder, in-line eight-cylinder and star-shaped.
With the streamlining of the design of engines, thanks to the introduction of the above principles, the number of cylinders was now determined for engines depending on their power. And further, the question arose about their optimal location.
The simplest layout option appeared first - an in-line arrangement of cylinders. This type involves their installation in a row one after the other. However, this arrangement is relevant for engines with no more than six cylinders. In this case, the most common four-cylinder options. Two- and three-cylinder engines are relatively rare, although they appeared at the beginning of the 20th century. Five-cylinder engines are also not very common, besides, they were developed only in the mid-70s. Six-cylinder in-line engines are currently losing popularity. The in-line layout of eight-cylinder engines was no longer used in the 30s.
The use of a V-shaped scheme for motors with a large number of cylinders is due to layout considerations. If you use an in-line layout for multi-cylinder power units, they will turn out to be too long, and there will be a problem with their placement under the hood. Now the most common is the transverse layout, and it is very difficult to place an in-line even six-cylinder power unit in this way. In this case, the greatest problems arise with the placement of the gearbox. That is why such engines yielded inprevalence of V6. The latter can be positioned both longitudinally and transversely.
The scheme under consideration is most often used on large-volume engines. They are installed mainly on sports and premium models among cars, as well as on heavy SUVs, trucks, buses, tractors.
V8 main parameters include volume, power, camber angle, poise.
This parameter is one of the main ones for any internal combustion engine. At the beginning of the history of internal combustion engines, there was no relationship between engine size and number of cylinders, and the average volume was much higher than now. So, a 10 liter single-cylinder engine and a 23 liter six-cylinder engine are known.
However, later the cylinder volume regulations mentioned above and the relationship between volume and power were introduced.
As mentioned, the layout in question is used mainly for multi-liter power units. Therefore, the volume of the V8 engine is usually at least 4 liters. The maximum values of this parameter for modern engines of cars and SUVs reach 8.5 liters. Trucks, tractors and buses are equipped with larger power units (up to 24 liters).
This characteristic of the V8 engine can be determined based on the specific liter power. For a gasoline atmospheric engine, it is 100 hp. Thus, a 4 liter motor has a power ofaverage 400 hp Hence, higher volume options are more powerful. In the case of some systems, especially supercharging, the liter capacity increases significantly.
This parameter is relevant only for V-engines. It is understood as the angle between the rows of cylinders. For most powertrains, it is 90 °. This arrangement of cylinders is common because it achieves low vibration levels and optimal ignition of the mixture and creates a low and wide engine. The latter has a positive effect on handling, since such a power unit helps to reduce the center of gravity.
Motors with a 60º camber angle are somewhat less common. Significantly fewer engines with even more minimal angle. This reduces the width of the engine, however, it is difficult to dampen vibrations on such options.
There are engines with a turned camber angle (180º). That is, their cylinders are located in a horizontal plane, and the pistons move towards each other. However, such motors are not called V-shaped, but boxer and are denoted by the letter B. They provide a very low center of gravity, as a result of which such engines are installed mainly on sports models. However, they are wide, so boxer motors are rare due to the difficulty of placement.
These phenomena in any case appear during the operation of a piston engine. However, designers strive to minimize them as much as possible, since they not onlyaffect comfort, but at excessive levels can lead to damage and destruction of the engine.
During its functioning, multidirectional forces and moments act. To reduce vibrations, it is necessary to balance them. One solution to this is to design the motor in such a way that the moments and forces are equal and opposite. On the other hand, it is enough to modify only the crankshaft. So, you can change the location of its necks and install counterweights on it, or use counter-rotation balance shafts.
First of all, it should be noted that among the common engines, only two types are balanced - in-line and boxer, and six-cylinder ones. Motors of other layouts differ in this indicator.
As for the V8s, they are quite well balanced, especially the right angled camber variants with perpendicular cranks. In addition, smoothness is given due to the possibility of ensuring a uniform alternation of flashes. Such engines have only two unbalanced moments on the cheeks of the outer cylinders, which can be fully compensated by two counterweights on the crankshaft.
V-engines differ from in-line engines in increased torque. This is facilitated by the scheme of the V8 engine. Unlike an in-line motor, where the direction of forces is directly perpendicular, in the engine under consideration they act on the shaft from two sides tangentially.This creates significantly more inertia, giving the shaft dynamic acceleration.
In addition, the V8 crankshaft is highly rigid. That is, this element is stronger, therefore it is more durable and efficient when working at limiting conditions. It also widens the engine's operating frequency range and allows it to rev faster.
Finally, V-engines are more compact than in-line engines. Moreover, they are not only shorter, but also lower, as can be seen from the photo of the V8 engine.
Motors of the layout under consideration are distinguished by a complex design, which causes a high cost. In addition, with relatively small length and height, they are wide. Also, the weight of the V8 engine is large (from 150 to 200 kg), which causes problems with weight distribution. Therefore, they are not installed on small cars. In addition, such motors have a significant level of vibration and are difficult to balance. Finally, they are costly to operate. Firstly, this is due to the fact that the V8 engine is very complex. In addition, it has a large number of details. Therefore, repairing a V8 engine is difficult and expensive. Secondly, such engines are characterized by high fuel consumption.
In the development of all internal combustion engines, there has recently been a tendency to increase efficiency and economy. This is achieved by reducing the volume and the use of various systems such as direct fuel injection, turbocharging, variable valve timing, etc. This has led tothe fact that large engines, including V8s, are gradually losing popularity. Multi-liter engines are now being replaced with smaller turbocharged engines. This has especially affected the V12 and V10 versions, which are being replaced with supercharged V8s, and the latter with V6s. That is, the average volume of engines is decreasing, which is partly due to the increase in efficiency, which is measured by liter power.However, sports and luxury cars still use powerful multi-liter power units. Moreover, their productivity has also increased significantly compared to the past thanks to the use of modern technologies.
Despite the prospects of replacing internal combustion engines with electric and other environmentally friendly engines, they still have not lost their relevance. In particular, V-shaped options are considered very promising. To date, designers have developed ways to eliminate their shortcomings. In addition, in their opinion, the potential of such power units is not fully disclosed, so they are easy to upgrade.