VW’s epic “W” Story

Chapter 1 – The Obsession

W-layout engines started way before VW, by a British precision engineering company D. Napier and Sons which made W12 engines for aircraft since the 1920s.

Napier Lion was a 24L behemoth producing 900 horsepower and even back in the day people were crazy enough to experiment with it and ended up shoving in a car which was called the Napier Bluebird which reached a top speed of 174mph in 1927.

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Disclaimer:

Before I get yelled at by seasoned engineers and know it all's, I'd like to make one thing clear, here ill be talking with respect to the automotive application of the W-layout and not the numerous industrial applications that this engine layout has found over the years, including and not limited to the W3 and W6 engines used in motorcycles of the early 1900s and the infamous W30 engines made by Chrysler developed for tanks during WW2.

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The Execution

The W12 isn’t exactly VW group’s first crack at an unconventional motor layout, after its air-cooled days, VW experimented with the possibility of making the most out of economical, front-wheel-drive compact and sub-compact platforms, and after trying everything from forced induction to experimental engine layouts, they found the answer with the VR6 engines. These engines are marginally larger than a regular Inline-4 which allows them to be placed transversely even in small cars designed for small engines like the Golf and Jetta. Even the Passat got the VR6 but the Passat was a big boy in comparison which made it the perfect testbed for their new W-format engine. A fun fact, the VR-6 Layout which everyone associates with VW these days was actually pioneered by Lancia back in 1922.

The VR-6 was also very smooth and relatively vibration-free because the narrow-angle V design combined with its classic firing order of “1 – 5 – 3 – 6 – 2 – 4” which was the same as a regular straight-6 (one of the most balanced engine configurations ever) and this was achieved by giving the engine offset crankpins, that canceled out most vibrations. Adding to this is the fact that it has a single-cylinder head that could serve both banks of cylinders and only two cam-shafts which apart from the packaging reasons mentioned earlier, also helps in reducing the overall weight and consequently the cost of production.

So as you would have guessed by now, the W12 in the Phaeton was essentially two VR6’s which resulted in a WR12 of 4-rows with 3-cylinders each, which meant that the two VR6’s joined at the crank at 72-degrees and 48-valves put in place to feed this massive powerhouse. But it didn’t end there, the cylinders were bored out from 81mm to 84mm, leading to its 6.0L displacement as opposed to the 5.8L they would have got from the standard bore of the largest VR6 of the time which was a 2.9L unit. This W12 was so significant that even after the disastrous sales figures, the W12 stayed in the VW portfolio and is found under the hood of Bentley models to date. Apart from the obvious candidates for this engine which included the Bentley Continental GT range and the Flying Spur, this powerplant made its way into the A8L, Audi’s flagship limo and a direct contender to the Phaeton, and they even managed to shove one into the Touareg, which can be best described as a Cayenne in a tuxedo, imagine having a Cayenne with a twin-turbo W12! But wait, we already got one of those, and it’s called a Bentayga.