W12 Engine (or VR6 x 2)

[ScharfR@aol.com]

Sometime last week a list member asked a few questions about the recently
unveiled Volkswagen W12 engine.  Among these was the issue of the angle
between the two banks of VR6 cylinders.  As it stands, the angle is 72
degrees, not because it needs to be, but because the physical space
constraints of the desired package size resulted in this being the most
agreeable angle.  According to what has been written in the European press,
the angle is not critical to balance since the two banks are, in themselves,
already balanced.  At least that's how they quoted Dr. Piëch.

The following is a general summary gathered from a number of press sources.
 I can't attest to the accuracy of all statements made (the press being what
it is), but it seems to fit together pretty well.  So, for your edification
(and in the hopes of provoking another scintilating battle of wits among our
wags), I present the following:

There has been a lot of discussion in the press lately about Volkswagen AG’s
plans to broaden the scope of its competitive offerings. There has even been
an acknowledgement that the company is “interested in principle” in acquiring
Rolls Royce -- lately offered for auction by its parent company Vickers.
 While much of the press reporting is pure speculation, Volkswagen did
recedntly drop a hint of what it is capable of producing. At the
just-concluded 1997 Tokyo Motor Show, the Volkswagen stand was the showcase
for a dramatic sports car concept with an even more dramatic powerplant. The
Volkswagen W12.

The radically styled car sports forward-hinged, swing-up doors, an
ultra-lightweight chassis comprised mainly of carbon-fiber reinforced
composite, and a projected top speed that is electronically limited to “only”
250km/h (155 mph). Making all this possible is a new engine design that mates
two VR6 powerplants to a common crankshaft with an included angle between the
two banks of 72 degrees. But that description oversimplifies the engineering
involved. While the basic architecture of the narrow-angle VR6 design is
preserved in each of the two banks of the new W12, it also incorporates other
 advances. The cylinder heads, for instance, are a new design featuring
4-valves per cylinder. That adds up to 48 valves, a total of four overhead
camshafts (with step-less variable cam timing), 5.6 liters of displacement,
420 horsepower (at 5,800 rpm) and 308 lb. ft. of torque (at a very low 3,000
rpm).

The engine is remarkably compact, thanks to the unique cylinder spacing of
the VR6 concept. In overall length, it is shorter than a four cylinder inline
engine. In width, it is scarcely wider than a conventional V6. And, thanks to
an aluminum cylinder block and its compact size, the 5.6L W12 weighs less
than the 4.2L V8 in the Audi A8.

The bright yellow sports car surrounding the W12 could easily be the star of
the show, were it not for the remarkable engine. The car was created in
cooperation with Ital Design, the famed italian studio known for many of the
world’s most advanced and exciting automotive designs. The carbon fiber
reinforced chassis offers great strength and stiffness while weighing only
2,650 lbs. – that’s over 600 pounds lighter than the all-aluminum Acura NSX!
With a six-speed sequential manual transmission and all-wheel drive, this car
needn’t feel shy around any of the world’s most outlandish exotic cars.

As to where all this is leading, there has been no formal announcement.
During the Tokyo show, it seemed clear that the car itself is to remain a
concept. However, Dr Ferdinand Piëch, Chairman of the Board of Volkswagen AG,
had promised an “engine of greater than six cylinders” to power a new
generation of cars that will position Volkswagen (and other brands within the
group) to compete with the world’s best and most respected brands. This
powerplant certainly fills that bill.