VR6 The Special German Engine
VR or (Vee-Inline) engines are basically a mixture between the inline engine and V configuration engine.
VR is a V engine with a very narrow-angle of 10.6 or 15 degrees between the cylinder banks but with a single cylinder head which makes it need only 2 camshafts (DOHC) regardless the engine has 2 or 4 valves per cylinder.
VR engines were produced by the Volkswagen group in 1991, with the most known VR6 engine on the Volkswagen Passat B3 and the Volkswagen.
Corrado coupe with 2.8L displacement and 172 Horse Power:
VR6 engine has been updated many times from 1991 until 2006 until the Volkswagen group introduced its smaller, more compact sibling, the VR5. VR6 is a more complex engine than the Inline 6 but simpler than V6, and it cost less than the Regular 60 or 90 degrees V configuration.
The length of the intake and exhaust ports are different in VR engines because of the shift between the cylinder bores to the sides but with a single flat cylinder head with slanted pistons (Veyron similar).
The difference in the intake and exhaust port size ensures that the same volume of air is going in and out of the combustion chamber.
The VR engine has a single Intake manifold and single Exhaust manifold, making it simpler and lighter than a V configuration. The VR6 engine came with variable displacements between 2.5 and 3.6 liters.
Two valve trains have been introduced into the VR6 engine, 12 valves and 24 valves, as shown in the above diagram. VR6 engine have the exact same firing order of the inline 6 engine (1,5,3,6,2,4) pairs (1,6);(2,5);(3,4).
Pros and cons:
The VR6 is a well-balanced engine like the inline 6 but with additional counterweights on the crank-shaft due to the offset between the cylinders to ensure smoother revs. The VR6 has a narrow packaging than a V6, and it’s shorter Than An Inline 6 engine which makes it ideal for front-wheel-drive cars.
VR6 size helps to have bigger displacement than Inline 4 engine in front-wheel-drive cars creating more power. The worst thing about this engine is that there is a restricted bore size because the cylinders are so close to each other, and the wall thickness is not that large, so it can’t let the bore size get enlarged.
- Advanced V-VR breed:
Volkswagen group in 2001 introduced a new configuration to car engine designs which have been used in aircraft between 1917 and 1930, which is the” W” engine. W engine is basically 2 VR engines stuck together in a V shape as the Bentley 6.0 W12 its basically 2 VR6 engines sharing a single crank-shaft.
The W engine has a large total displacement like the W12 6.0, creating high power but relatively small physical size. W12 engine consists of 4 banks of 3 cylinders with only two flat cylinder heads.
W engines produce very high torque due to the complex angle of the four banks, making a force against the single crank-shaft from the two sides. In the end, the VR engines are extraordinary, unique, and reliable engines with compact size and large displacement that works in all types of drive trains (Front Wheel Drive- Rear Wheel Drive- and All Wheel Drive).