W12 engine

The 6.0-liter W12 is a compact engine arrangement used in the Volkswagen / Audi AG vehicles, A8, Phaeton, and Continental GT and GTC. The "double-vee" arrangement allows for a small overall size in comparison with a tradition V- or Flat 12 engine. This engine made its debut in 1997 Volkswagen W12 Nardo concept supercar at the Tokyo Motor Show. The arrangement is also used in the 4.0-liter W8 used in the 2004-2006 Volkswagen Passat and the 8.0-liter W16 of the Bugatti Veyron 16.4.

Technical[]

The Nardo version of the W12 was 5.6-liters in displacement with a length of only 20.1 inches, and a width of 27.6 inches. It produced a claimed 420 hp @ 5800 RPM and 390 lb-ft of torque @ 3000 RPM.

The Volkswagen Phaeton W12 uses a detuned version of the A8 engine producing 444 hp @ 6000 RPM and 406 lb-ft of torque at 3250 RPM. The compression ratio is also lower at 10.5 : 1.

The Bentley Continental Flying Spur, Continental GT and Continental GTC all use a twin-turbocharged version producing 552 hp (560PS/411kW) @ 6100 RPM and 479 lb ft (650Nm) of torque @ 1600 RPM. The compression ratio of this version is 9.0 : 1.

The full specifications for the Audi A8L W12 are courtesy of the Audi Technical Specifications

A8L W12
Type	DOHC aluminum allow 15-degree V-angle, 72-degree bank angle W12
Displacment	6.0-Liters (366 cu. in.)
Bore	3.31 inches (84 mm)
Stroke	3.55 inches (90.2 mm)
Compression Ratio	11.0 : 1
Fuel Requirement	Premium unleaded 91 AKI / 95 RON
Horsepower (SAE)	450 @ 6200 RPM
Torque (lb-ft)	428 @ 4000-4700 RPM
Engine Design
Cylinder Block	Aluminum silicon alloy (Alusil)
Crankshaft	Forged, heat treated steel, 7 bearings. Offset crankpins. 21.2 kg
Cylinder Head	Aluminum Alloy
Valvetrain/Intake	DOHC, double overhead camshafts driven by a single chain, low friction roller cam followers, 2 inlet and 2 exhaust valves per cylinder. Infinitely variable timing control for camshafts (52-degrees at inlet and 22-degrees at exhaust valves)
Firing Order	1 - 12 - 5 - 8 - 3 -10 - 6 - 7 - 2 - 11 - 4 - 9
Cooling System	Water-cooled, thermostatically controlled radiator fan. Water pump in cylinder block/crankcase map-controlled electronically controlled continued coolant circulation pump, coolant thermostat, hydraulic fan and electric fan, coolant circulation, and water cooled alternator.
Lubrication System	gear pump, pressure lubrication, full flow through oil cooler
Fuel Injection/ Ignition System	Fully electronic engine management system utilizing Bosch Motronic ME7.1.1, sequential injection with electronic throttle control, hot-film air-mass sensing, cylinder selective knock control via 4 sensors and permanent lamda control.
Emission System	Air gap insulated exhaust manifolds, 4 close-coupled 3-way ceramic catalytic converters, 8 oxygen sensors
Capacities
Engine Oil	13 qt. (12.5 l)
Cooling System	19.972 qt. (18.9 l)

Images[]

See Also[]

Piston engine configurations This box: view • talk • edit
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Other	Hemi • Recuperator • Turbo-compounding