The VR6 engine is a V6 with narrow-angle pistons located between the cylinders and a single head spanning both banks of cylinders. What is worth knowing about this engine? We present the most important information!
The VR6 engine was developed by the Volkswagen Group. The first engine was introduced in 1991. As a curiosity, it can be said that VW was also involved in the production of the VR5 engine, whose design was based on the VR6 engine. More information about the VR6 engine can be found in our article.
Basic information about the Volkswagen engine
At the very beginning, you can “decipher” the VR6 abbreviation. The name comes from an abbreviation created by a German manufacturer. The letter “V” refers to the “V-motor”, and the letter “r” to the word “Reihenmotor”, which in translation – a straight, in-line engine.
For the VR6 models, a common head was used for the two banks of cylinders. The engine is also equipped with two camshafts. They are present both when the version of the engine has two and four valves per cylinder.
In this way, the structure of the engine is easier to service, which allowed to reduce its operating costs. The VR6 engine is still produced today. Models equipped with this engine include:
- Volkswagen Golf MK3, MK4 and MK5 Passat B3, B4, B6, B7 and NMS, Atlas, Talagon, Vento, Jetta Mk3 and MK4, Sharan, Transporter, Bora, New Beetle RSi, Phateon, Touareg, EOS, CC;
- Audi: A3 (8P), TT Mk 1 and Mk2, Q7 (4L);
- Seat: Alhambra and Leon;
- Porsche: Cayenne E1 and E2;
- Skoda: Superb 3T.
12 cylinder version
The engines that were initially produced had two valves per cylinder for a total of twelve valves. They also used a single camshaft for the intake and exhaust valves at each block. In this case, no rocker arms were used either.
The first version of the VR6 had a displacement of 90.3 millimeters with a total displacement of 2.8 liters. An ABV version was also created, which was distributed in some European countries and had a volume of 2.9 liters.
It is also worth mentioning that due to the two rows pistons and cylinders with a common head and head gasket, the piston head or top surface is inclined.
For the 12-cylinder version, a V angle of 15° was chosen. The compression ratio was 10:1. The crankshaft was located on seven main bearings, and the journals were offset by 22° from each other.
This made it possible to offset the arrangement of the cylinders, as well as to use a 120° gap between successive cylinders. The control system of the Bosch Motronic engine was also used.
Version with 24 cylinders
In 1999, a 24-valve version was introduced. One camshaft operates in it, which operates the intake valves of both banks. The other, on the other hand, operates the exhaust valves of both banks.
This is done using valve levers. This design specificity is similar to the DOHC double overhead camshaft. In this installation, one camshaft operates the intake valves and the other the exhaust valves.
W-engines – how are they related to the VR model?
Quite an interesting solution created by the Volkswagen Group was the construction of engines with the designation W. The design was based on the connection of two VR engines on the same crankshaft – at an angle of 72 °. The first of these engines was the W12. It was produced in 2001.
The successor, the W16, was fitted to the Bugatti Veyron in 2005. The engine was designed with a 90° angle between the two VR8 engines and was equipped with four turbochargers.
What is the difference between a traditional V6 and a VR6 engine?
The difference is that a narrow 15° angle between the two banks of cylinders is used here. This makes the width of the VR6 engine smaller than the V6.
For this reason, the VR engine is easier to fit into the engine bay, which was originally designed for a four-cylinder engine. The VR6 engine has been designed so that it can be mounted transversely in cars with front-wheel drive.