New Bentley Continental GT - stunning performance

Engine details confirmed

Highlights
- The fastest, most powerful four seat production coupé in the world
- Twin turbo, 6-litre, W12 engine developing 560PS and 650Nm (479lb ft) of torque
- Maximum torque delivered at just 1600rpm
- Top speed of over 190mph (300km/h)
- 0-60mph in 4.7sec (0-100km/h in 4.8sec)
- The most compact turbocharged twelve cylinder engine on the market

Introduction
The heart of any Bentley is its engine. As the Bentley Continental GT has now made its world debut, Bentley Motors can reveal the full technical specification of the powerplant used by the fastest, most powerful four seat coupé in the world. Two figures alone are enough to whet the appetite: it accelerates from 0-60mph in 4.7sec (0-100km/h 4.8sec) and reaches a top speed in excess of 190mph (300km/h).

Engine: a W12 format, totally re-engineered for the Continental GT by Bentley

Providing the power for the Continental GT is a 5998cc, four camshaft, 48-valve, twin turbocharged W12 engine. Its power output is 560PS (411kW) at 6100rpm. Maximum torque is 650Nm (479lb ft) which may sound an impressive enough statistic in isolation, but its true significance only becomes apparent when you learn that it is generated at just 1600rpm. Typically, a performance car engine will force the driver to wait until it is spinning at between 3-5000rpm before it will deliver maximum thrust; in the Continental GT it's all there at barely more than idling speed. The engine has been engineered to deliver consistent, explosive torque all the way to its red-line.

But this is just the start of this engine's story: it has many other distinctions to its name. Its exterior dimensions, for instance, make it the smallest 12-cylinder engine currently in production, despite its considerable 6-litre displacement. The engine is just 653mm long, 820mm high and 714mm wide. This has been made possible by its 'W' formation where instead of arranging the cylinders in two long rows as you would in a conventional V12 configuration, each bank of cylinders is actually staggered, effectively creating two V6 engines mated on a common crankshaft. The angle between the two main banks is 72deg, that between the staggered cylinders just 15deg. The result of this is an exceptionally compact motor, a trait that brings advantages in many areas. Clearly it helps with weight distribution as a small engine is easier to locate nearer the centre of the car. This in turn helps the overall packaging of the car and, in particular, its frontal crash performance, a crucial consideration in a Bentley which has a short front overhang as one of the main features of its design language.

It is no secret that the basic engine architecture has been supplied to Bentley from its parent company, the Volkswagen Group, but by the time Bentley's powertrain team had finished re-engineering it to an exclusive specification for the Continental GT, it can now be considered a unique engine in its own right.

Clearly the major engineering challenge was to adapt the engine to accept twin turbochargers, a process that required major re-engineering of the block, the replacement of many internal components and all new inlet and exhaust systems.

The engine features special pistons, specifically designed for the Continental GT in order to deliver the desired compression ratio of 09:01. The engine also features seven main bearings, pent-roof combustion chambers and variable valve timing on both inlet and exhaust valves. The timing is infinitely variable within its fixed range which is some 52 degrees on the inlet camshafts and 22 degrees on the exhaust camshafts.

A huge amount of work was also undertaken to ensure the Continental GT could use air to air intercoolers rather than the water to air variety. Fitting them within the already cosy confines under the Continental GT's bonnet was not the matter of the moment, but Bentley's engineers regarded their inclusion in the specification as not negotiable and, after several months work, they were duly integrated into the under bonnet package.

The Continental GT also uses a dedicated exhaust system, using two six-into-one manifolds. Much attention has been paid not only to ensure the exhaust provides maximum efficiency, but also that its sound is appropriate to the fastest Bentley road car in both tone and volume.

The twin turbochargers operate at only the comparatively conservative boost pressure of 0.7bar to equip the Continental GT with its headline performance. Given this, the existence of maximum torque at 1600rpm and the engine's 6-litre capacity and it's easy to see how turbo-lag, the sole undesirable side-effect of this variety of forced induction, has been effectively removed from the equation. As with all Bentley-designed powerplants since the birth of the company in 1919, smooth power is not something you need to wait or ask for - it is there, at your disposal at every point of the rev-range from idle to its 6300rpm red-line.

Controlling all this power is Bosch's state of the art ME 7.1.1 engine management system which comes complete with two throttle bodies, exhaust gas temperature regulation, boost pressure regulation, two air mass sensors, four knock sensors with adaptive learning and the latest ESP 5.7 electronic stability programme. Ignition is achieved without the need for a distributor, thanks to each cylinder being provided with its own coil. The engine is fully compliant with future Euro IV emissions regulations and has been calibrated to run on standard 95RON octane pump fuel.

Such is the power of the Bentley Continental GT's powertrain that Bentley engineers took the decision to reinforce its engine mounts with kevlar bindings to make sure it does not move even under the most extreme circumstances.

Powertrain testing
The engine in the Continental GT has undergone some of the most gruelling and exhausting test procedures of any engine in order to ensure that it can be depended upon to accommodate all and more than any owner could ever expect of it. Naturally prototypes have and continue to rack up millions of miles in some of the hottest, coldest, driest and most humid places on earth but perhaps no single test illustrates the relentless pursuit of engineering perfection than those tests performed with the engine out of the car and sitting on a bench.

Perhaps the most eye-opening of these is a test where the engine is switched on and revved to maximum revolutions (6300rpm) from cold and then left there not for a few minutes or even a few hours. It is left to run at maximum speed for 100 hours or, put another way, over four Le Mans 24-hour races on the trot.

Another test puts the engine through an advanced programme of cyclical accelerations, decelerations and steady state running at all points in the rev range for 500 hours non-stop or, to put that it perspective, just four hours short of three weeks.

The engine has also been exposed to prolonged thermal shock cycling where internal temperatures are swiftly brought to a peak whereupon its coolant is replaced by ice-cold fluid in order to induce the swiftest possible drop in temperature before the engine is re-heated up to maximum temperature again and the process is repeated.

Conclusion
As can be seen, the engine chosen to power the Continental GT offers rather more than a world-beating power output. It was designed specifically not simply to deliver unprecedented performance, but to do so in a way that was inimitably Bentley. It would have been possible, for instance, to use a smaller capacity 'screamer' to develop the same power at much higher revs, but such an engine would force the driver to work much harder and could never generate torque like the Continental GT. The effortless response would disappear and while the result might still be a fine engine, it would not be a Bentley engine.

Engine
Type W12, cast aluminium alloy block and cylinder
heads, with aluminium wet sump lubrication,
twin 3K turbochargers, air to air intercooling
Dimensions (l/w/h) 653mm, 820mm, 714mm
Bore and stroke 84mm/90.2mm
Displacement 5998cc
Compression ratio 09:01
Boost pressure 0.7bar
Engine management Bosch ME 7.1.1
Valve gear Four overhead camshafts, four valves per cylinder
Emissions standard Euro IV
Fuel rating 95/98 RON
Power 560PS (552bhp) (411 kW) at 6100rpm
Torque 650Nm (479lb ft) at 1600rpm

Performance
0-60mph 4.7sec (0-100 km/h 4.8sec)
Top speed over 190 mph (over 300 km/h)