(from VW Press Release) In
the future, all Volkswagens in the upper and luxury classes will be
equipped with the high-torque W engines. They are characterised by
exceptionally low levels of vibration and the best possible acoustic
qualities. They are, depending on the model in question, used as
standard- in the W12 Coupé for example - or as an option. The Volkswagen
brand will launch them as an eight-cylinder, as can already be seen in
the Passat W8, and as a twelve-cylinder version with varying levels of
output and set-ups. A 16-cylinder version has also been developed on
this basis within the Volkswagen Group. It will be used as of 2003 in
the Bugatti EB 16·4 Veyron, which was shown in its most current version
last September at the Frankfurt Motor Show.
The technology of the twelve cylinder engine integrated in the design
study W12 Coupé: with a length of 513 millimetres, a height of 715
millimetres and a width of 710 millimetres, the engine is particularly
compact. The capacity of the W12, which weighs just 239 kilograms, is
5,998 cm³. The engine, which is located between the passenger
compartment and the rear axle, has an extraordinarily torsionally rigid
aluminium crankcase with wear-resistant cylinder sleeves. A further
indication of the systematic light-weight construction approach can be
seen in the valve covers and timing chain covers made of magnesium.
The basic layout of the W12 engine is made up of two very thin V6
four-valve modules which are configured at an angle of 72 degrees with a
joint crankshaft with seven main bearings to make up a V-V arrangement,
i.e. a "W". The cylinder angle is just 15 degrees Within the two V6
banks. This makes the construction, which is very compact in comparison
to V12 engines, possible.
All other construction details of the W12 engine, which has a
compression ratio of 12:1, are also indications of an extremely
high-tech assembly: the spark plugs are positioned centrally in the
pent-roof combustion chamber, making optimal combustion possible; the
same applies for the flow-optimised intake ports. A double-flow
magnesium variable intake manifold supports the particularly dynamic
torque curve. The variable intake and exhaust valve timing has a
decisive influence on power development: the inlet camshafts can be
continually adjusted through 52 degrees and the corresponding value for
the exhaust camshaft is 22 degrees.
It is no wonder, when considering this technology, that a high priority
was given to the performance of all materials in the development phase
of the W12 engine. For example, Volkswagen is only using engine oils
from the Shell Helix family for the W12 Coupé.
The emissions levels have been perfectly regulated. The W12 Coupé has
been developed so that it will meet the requirements of the stringent
EU-4 norm due to its four starter catalysts and two catalysts in the
standard production version.
