W8 engine

From Wikipedia, the free encyclopedia
Jump to: navigation, search

A W8 engine is an eight-cylinder piston internal combustion engine in a W configuration. The W8 can be imagined as flat plane crank V8 engine combining two narrow-angle (15 degree) VR4 engine blocks, mounted juxtaposed at 72 degrees to each other and coupled to one crankshaft. Nearly square external dimensions mean the large eight-cylinder engine will fit in the space typically taken by a V6 engine.

Volkswagen W8 engine[edit]

Volkswagen W8 engine
Overview
Manufacturer Volkswagen
Also called 4.0 W8
Production 2001–2004
Combustion chamber
Configuration WR8
Displacement 3,999 cc (244.0 cu in)
Cylinder bore 84.0mm
Piston stroke 90.2mm
Valvetrain DOHC/4 valves per cylinder
Compression ratio 10.8:1
Combustion
Fuel system multipoint indirect injection
Fuel type petrol
Output
Power output 275 PS (202 kW; 271 hp)
Torque output 370 N·m (270 lb·ft)
Chronology
Predecessor -
Successor -

The Volkswagen Group W8 engine was installed longitudinally in the Volkswagen Passat (B5.5) from September 2001 to September 2004,[1] but sales were minimal at only 10,000 units worldwide per year. The Passat W8 was positioned as Volkswagen Passenger Cars' "premium" car, before the Volkswagen Phaeton was introduced.

The 4.0-litre - 3,999 cubic centimetres (244.0 cu in) W8 engine produced 202 kilowatts (275 PS; 271 bhp) at 6,000 revolutions per minute (rpm) and 370 newton metres (273 lbf·ft) of torque at 2,750 rpm, yet was considered a fuel-efficient eight-cylinder engine due to the design. It also had a two-stage resonance induction system to boost cylinder filling across the engine speed range. It had two simplex roller chain-driven (relay method, using three chains) double overhead camshaft (two overhead camshafts per cylinder bank, hence "quad cam"), and twin balance shafts to smooth out residual vibrations inherent in the layout. One additional advantage was that the W8 shared some components and machining with narrow-angle VR5 and VR6 engines, leading to cost reduction in one of the most expensive engines Volkswagen Passenger Cars has ever produced.

The 2005 redesign of the Passat (B6) changed the engine's mounting configuration to transverse. The W8 is too large physically to be mounted in such a way, so the 'large' 3.6-litre VR6 engine has replaced its position at the top of the range.

References[edit]

  1. ^ "VW Passat W8 4motion". WorldCarFans.com. Volkswagen AG. 22 April 2002. Retrieved 30 December 2009.