Bentley Mulsanne Engine Detailed

Bentley's new 6¾ litre, twin-turbocharged V8 engine blends state-of-the-art technology with a classic configuration that's propelled Crewe's finest cars for over 50 years. Like the rest of the Mulsanne, every 505bhp V8 is hand-assembled and fully tested by Bentley's technicians.

(Crewe, England) Right at the heart of Crewe's new flagship Mulsanne is the company's famous V8 engine which is renowned for delivering the Bentley ‘wave of torque'. The V8 engine, the same configuration of which has powered some of the company's most iconic cars including the Arnage, Azure, Brooklands, the original Mulsanne, Turbo R and S2 Continental, has been completely re-engineered for the new Mulsanne.

The V8 configuration will strike a chord with aficionados, the 6¾ litre displacement having been the favoured option for many years. For the Mulsanne, however, the very latest technologies have been employed including two new control systems: cam phasing and variable displacement delivering even greater refinement as well as a 15 per cent improvement in emissions and fuel consumption.

The pioneering application of these new technologies in combination allows the Mulsanne's engine management system to adjust the V8's breathing for improved engine idle quality and torque delivery. However, by closing the valves of four of the eight cylinders, fuel economy is maximised when cruising.

All the major building blocks of the Mulsanne's engine are new including the lightweight componentry such as pistons, connecting rods and forged crankshaft which reduce reciprocating mass and internal friction for improved engine response. These significant changes are complemented by the introduction of a new eight-speed automatic transmission offering virtually imperceptible gearshifts.

In total over 300 new or significantly re-engineered components have been created for the Mulsanne engine and the famed Bentley ‘wave of torque' (1020Nm/752lb ft) is now delivered in full even earlier, at 1750rpm. This improvement in torque delivery from just above idle - as well as across the rev range - ensures that a mere tap of the throttle pedal will deliver phenomenal acceleration with 0-60mph achievable in just 5.1 seconds (0-100km/h in 5.3 seconds).

For Phil Cooper, Bentley's senior production manager in the engine build workshop, the new V8 engine has provided an opportunity to introduce a range of new technologies whilst retaining the hand-built skills at which his team has long excelled. Phil explains:

"Our new V8 takes nearly 30 hours to build and we never release an engine to our colleagues in the main build hall until we are literally prepared to put our name to it."

In the immaculately tidy V8 engine build area, where every set of craftsman's tools are stored and labelled with the exact precision of a surgeon's implements, the team use a combination of the high-tech and applied-by-hand skills to achieve the best results.

A state-of-the-art balancing machine ensures all the spinning components are rigorously tested (and if necessary rebalanced using tiny washers) and the level of accuracy achieved by this process ensures that when the engine is at idle there is not a hint of vibration. Alongside the use of the balancing machine, Bentley's engine builders still fit each of the pistons into the V8 block by hand as well as the 16 individual ball-bearings which are inserted into the valve train.

Once assembled, every Mulsanne V8 is tested over an 80-minute cycle by the team. The ‘hot testing' process tests the engine from idle through to maximum revs and the load on the engine is varied to simulate real-world driving conditions.

"Every element of the engine's performance is analysed and recorded before it is sent through to the build hall,"Cooper explains.

Whilst the V8 engineering and engine-build teams have introduced a host of new technologies and are working with hundreds of new parts, one classic touch remains unchanged - a signed engine maker's plate is still attached to every Crewe-built V8 to provide a reassuring symbol of quality, performance and reliability.