A W8 engine is an eight-cylinder

piston engine A reciprocating engine, more often known as a piston engine, is a heat engine that uses one or more Reciprocating motion, reciprocating pistons to convert high temperature and high pressure into a Circular motion, rotating motion. This article ...

with four banks of two cylinders each, arranged in a W configuration. In practice, the W8 engine is created from two narrow-angle (15 degree) VR4 engines mounted at an angle of 72 degrees from each other on a common

crankshaft A crankshaft is a mechanical component used in a reciprocating engine, piston engine to convert the reciprocating motion into rotational motion. The crankshaft is a rotating Shaft (mechanical engineering), shaft containing one or more crankpins, ...

. Thus, the resulting four banks align to form a "W". W8 engines are much less common than

V8 engine A V8 engine is an eight- cylinder piston engine in which two banks of four cylinders share a common crankshaft and are arranged in a V configuration. Origins The first known V8 was the Antoinette, designed by Léon Levavasseur, a ...

s, and the only W8 engine to reach production was manufactured by Volkswagen.

Volkswagen W8 engine

The Volkswagen 4-litre W8 engine was available in the Volkswagen Passat (B5.5) from September 2001 to September 2004. Production was minimal at only 11,000 units. The engine had a displacement of , had a peak power rating of at 6,000 rpm and a peak torque rating of at 2,750 rpm. Power and torque outputs were lower than competitors V8 engines with similar capacity, however the W8 engine was praised for its smoothness. Sales of the W8-engined Passat models were poor, and production was discontinued when the next generation of Passat switched from a

longitudinal engine In automotive engineering, a longitudinal engine is an internal combustion engine in which the crankshaft is oriented along the long axis of the vehicle, from front to back. See also: transverse engine Use This type of motor is usually used fo ...

to a

transverse engine A transverse engine is an engine mounted in a vehicle so that the engine's crankshaft axis is perpendicular to the direction of travel. Many modern front-wheel drive vehicles use this arrangement. Most rear-wheel drive vehicles use a longitudinal ...

layout, which made packaging of the wide W8 engine difficult. The W8 was effectively replaced by the Volkswagen 3.6-litre VR6 petrol engine.

4.0 WR8 32v 202kW

The 'W8' badged engine is an eight-cylinder

W engine A W engine is a type of piston engine where three or four cylinder banks share the same crankshaft, resembling the letter "W" when viewed from the front. W engines with three banks of cylinders are also called "broad arrow" engines, due to thei ...

of four banks of two cylinders, formed by joining two 15° VR4 engines, placed on a single crankshaft, with each cylinder 'double-bank' now at a 72° vee-angle. ;identification: parts code prefix: 07D, ID codes: BDN (09/01-09/04), BDP (05/02-09/04) ;engine displacement & engine configuration: 72° WR8 engine; bore x stroke: , stroke ratio: 0.93:1 – undersquare/long-stroke, 499.9 cc per cylinder, compression ratio: 10.8:1 ;cylinder block & crankcase: cast aluminium alloy with two-part cast aluminium alloy oil sump; five main bearings; die-forged steel crankshaft with split

crankpin A crankpin or crank pin, also known as a rod bearing journal, is a mechanical device in an engine which connects the crankshaft to the connecting rod for each cylinder. It has a cylindrical surface, to allow the crankpin to rotate relative to th ...

s; Lanchester principle

balance shaft Balance shafts are used in piston engines to reduce vibration by cancelling out unbalanced dynamic forces. The counter balance shafts have eccentric weights and rotate in the opposite direction to each other, which generates a net vertical force ...

s one above the other, counter-rotating at twice the crankshaft speed, symmetric to the middle of the crankshaft, upper one driven by a toothed belt ;cylinder heads & valvetrain: cast aluminium alloy; four unequal-length valves per cylinder, 32 valves total, low-friction roller finger

cam follower A cam follower, also known as a track follower, is a specialized type of roller or needle bearing designed to follow cam lobe profiles. Cam followers come in a vast array of different configurations, however the most defining characteristic is ...

s with automatic

hydraulic Hydraulics () is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counterpart of pneumatics, which concer ...

valve clearance compensation, simplex roller chain-driven (relay method, using three chains) double overhead camshafts, continuous vane-adjustable variable valve timing for intake and exhaust camshafts with up to 52° variance inlet camshafts and 22° for exhaust camshafts ;aspiration: hot-film air mass meter, single throttle body with electronically controlled Bosch 'E-Gas' '

drive by wire Drive by wire or DbW in the automotive industry is the technology that uses electronics or electro-mechanical systems in place of mechanical linkages to control driving functions. The concept is similar to fly-by-wire in the aviation industry. D ...

' throttle

butterfly valve A butterfly valve is a valve that isolates or regulates the flow of a fluid. The closing mechanism is a disk that rotates. Principle of operation Operation is similar to that of a ball valve, which allows for quick shut off. Butterfly valves ...

, four-part two-channel cast aluminium resonance intake manifold ;fuel system, ignition system, engine management: two linked common rail fuel distributor rails, multi-point electronic sequential indirect fuel injection with eight intake manifold-sited fuel injectors; centrally positioned NGK longlife spark plugs, mapped direct ignition with eight individual direct-acting single spark coils; Bosch Motronic ME electronic engine control unit (ECU), cylinder-selective knock control via four knock sensors, permanent

lambda Lambda (; uppercase , lowercase ; , ''lám(b)da'') is the eleventh letter of the Greek alphabet, representing the voiced alveolar lateral approximant . In the system of Greek numerals, lambda has a value of 30. Lambda is derived from the Phoen ...

control; 95 RON/ROZ(91 AKI) EuroSuperPlus (premium) unleaded recommended for maximum performance and fuel economy ;exhaust system: vacuum-operated

secondary air injection Secondary air injection (commonly known as air injection) is a vehicle emissions control strategy introduced in 1966, wherein fresh air is injected into the exhaust stream to allow for a fuller secondary combustion of exhaust gases. Development ...

pump for direct injection into exhaust ports to assist cold start operation, one cast iron exhaust manifold per cylinder bank with integrated

ceramic A ceramic is any of the various hard, brittle, heat-resistant, and corrosion-resistant materials made by shaping and then firing an inorganic, nonmetallic material, such as clay, at a high temperature. Common examples are earthenware, porcela ...

catalytic converter per cylinder bank, four heated

oxygen sensor An oxygen sensor is an electronic component that detects the concentration of oxygen molecules in the air or a gas matrix such as in a combustion engine exhaust gas. For automotive applications, an oxygen sensor is referred to as a lambda senso ...

s monitoring pre- and post catalyst exhaust gasses, EU4 compliant ;dimensions: mass: , length: length, width: , height: ;DIN-rated motive power & torque output: at 6,000 rpm; at 2,750 rpm ( MEP); max. engine speed: 6,400 rpm (19.2 m/s) ;references:

Applications

* Volkswagen Passat B5.5 W8 4motion

Awards

:was voted 'best technical innovation', and awarded the "Golden Pegasus" by ''"Za ruljom"'' at the Moscow Motor Show

References

{{Piston engine configurations Piston engine configurations 08