It can be seen intuitively that when the engine is not equipped with accessories, the V12 engine is very long, while the cylinder block of the W12 engine is relatively compact, not even much larger than the cylinder block of the V8 engine. The W12 engines used by Volkswagen, Audi and Bentley are all produced at the Bentley factory in the UK, with an annual production capacity of only 90%. It can be seen intuitively that when the engine is not equipped with accessories, the V12 engine is very long, while the W12 engine The cylinder block is relatively compact, not even much larger than the cylinder block of the V8 engine.
The W12 engines used by Volkswagen, Audi and Bentley are all produced at the Bentley factory in the UK, with an annual production capacity of only 9,000 units. The original prototype of the Volkswagen Group's W12 engine was cast by combining the cylinder blocks of two VR6 engines. VR6 engine is a small angle V6 engine. The cylinder block of a single VR6 engine is shown in the figure below:
It can be seen that the two rows of cylinders are very close to each other, which is obviously different from the traditional V-shaped engine. The included angle of a traditional V-shaped engine is generally 60 degrees or 90 degrees. After VR6 is put together, the resulting W12 engine block is very compact. However, the mass-produced Volkswagen W12 engine was not simply put together. Many cooling pipes and cylinder layouts must have been carefully designed. The prototype of the Volkswagen Group W12 was unveiled around 2001. Its cylinder block is as follows:
So, this is the cylinder block structure of the W12 engine, which is the combination of two small angle V6 engines. Compared with in-line cylinder engines, another biggest feature of V-type engines is that two connecting rods are mounted on one crank pin, while in-line cylinder engines only have one connecting rod mounted on one crank pin. What is the crank pin? See the picture below:
Now, what needs to be considered is how to combine the power of the two engines together. Due to structural reasons, the W12 engine had to stagger a crank pin
The above are the structural characteristics of the Volkswagen Group's W12 engine. Compared with the V12 engine, its structure is actually not complicated. The cylinder head and valve mechanism are not much more complicated than the V12 engine, but the cylinder block is a bit special. Although it is produced by the same factory, there must be different models. The Audi A8L uses a 6.3L-W12 with more than 500 horsepower, and Bentley uses a 608-horsepower 6.0T-W12.
Extended information
The W12 engine is more compact, allowing the engine compartment to be shorter and more convenient for full-time four-wheel drive layout
The W12 engine is mainly used in the Volkswagen Group Its high-end car products, such as Audi A8 and Bentley. Volkswagen's Phaeton and Touareg were also equipped with W12 engines, but from a positioning perspective they were not in line with Volkswagen, so they are basically no longer produced. The W12 engine can be understood as the superposition of two V6 engines. The advantage is that the engine can be made smaller and flatter, and the weight is much lighter than the V12 engine.
One of the advantages of the W12 is that it can dig out a larger body space in the shorter vehicle length and wheelbase
The benefit of being more compact is that it can get a relatively short car. The engine compartment allows for a more ample cab space with the same body length. We can see from the shorter engine compartments of the Phaeton and A8 compared to the Mercedes-Benz S and BMW 7.
The V12 engine has a long history and the technology is also very mature
It is very difficult to lay out the four-wheel drive system for the V12 engine. The 12-cylinder engine in a V-shaped arrangement will take up a relatively long space. Not only does the engine compartment need to be very long, but also the space for laying out a four-wheel drive system is a big challenge. In the past, the top V12 engine models of Mercedes-Benz and BMW only had rear drive, but in recent years, the BMW 7 Series has made a breakthrough. Although there is no such curse, it is undeniable that laying out the front-drive system under the V12 engine is indeed a complicated project.