2019 has been a big year for Bentley, with the British marque celebrating its 100th anniversary. But here's another... its V8 engine celebrates 60 years, making it the longest-serving V8 in production.
First used in the 1959 Bentley S2 (replacing a straight-6), the V8 has powered 23 Bentley models and still powers the Mulsanne luxury sedan today. Of course, it has been significantly re-engineered through the years, to the point that today it develops (with twin-turbocharging) just shy of 400kW and 1 100Nm of torque in the Mulsanne Speed.
Designed, engineered and hand-built in Crewe, England, close to 36 000 of these V8 engines have been manufactured, with the latest twin-turbo 6¾-litre V8 engine requiring 15 hours of craftsmanship to build. While it is true that every part of the original S2 engine has been re-engineered over the decades, the basic principles and dimensions that have defined the engine for the last 60 years remain the same.
The same... but different. The original V8 has been completely re-engineered through the past 60 years.
Dr Werner Tietz, Member of the Board, Engineering at Bentley Motors, said: ‘The original V8 was designed to deliver a step-change in performance, along with smoothness, reliability and refinement. The engine was tested over hundreds of thousands of miles in the toughest conditions, as well as at full throttle for 500 hours. The success of Bentley’s acclaimed 6¾-litre V8 today in the Mulsanne owes much to that ethos.”
At the beginning
Development of the first Bentley V8 engine started not too long after the iconic British marque moved into its current headquarters in Crewe. Jack Phillips, Senior Engine Designer, was asked to undertake a confidential study to find a replacement for the six-cylinder engine used in the Bentley Mark VI, R-Type and S1.
The Bentley S2 was the first from Crewe to feature the new V8 engine in 1959.
He was told that this new engine should be at least 50 per cent more powerful than the 6-cylinder it would eventually replace, while occupying the same space under a bonnet with no increase in weight. A ‘V’ configuration was the obvious choice and, amazingly, the first engine ran just 18 months after the start of the design process.
The resulting 6.2-litre V8 engine was roughly 14kg lighter than the 6-cylinder powerplant and made its debut in the Bentley S2 of 1959. The car featured air conditioning, power steering, electrically-operated ride control and electric windows – making it arguably the most luxurious car of its era.
Then came the T-Series
The original V8 engine had to be redesigned to fit into the new T-Series cars, introduced for 1965. The engine department focused on improving performance, while reducing the overall engine dimensions to fit the space available under a lowered bonnet.
Engine capacity was increased to the now-famous 6¾-litres in 1971 through an increase in stroke from 3.6 to 3.9 inches.
In twin-turbocharged form the V8 still powers the Mulsanne today.
Then came the arrival of the first Bentley Mulsanne in 1980, and the need for stricter emission controls and improved passenger safety in the event of a front-end impact. For the latter requirement a collapsible water pump was developed, which effectively shortened the engine by 10.1 cm.
The biggest single change to the engine was for the launch of the Mulsanne Turbo. With the fitment of a large single turbocharger, the 6¾-litre engine become the first "blown" Bentley engine since those that powered Tim Birkin’s Blower Bentleys of the 1920s. Power and torque increased hugely, and the single turbo setup was eventually replaced by a twin-turbo design. Fuel injection, variable valve timing and cylinder deactivation have all been engineered-in to the engine since.
Modern-day excellence
The recipe has been consistent - luxury, grace and loads of torque and refinement from that V8.
Today, still, each Bentley engine is handcrafted in Crewe, England. Every component of the current 6¾-litre twin-turbo V8 in the Mulsanne is selected and installed by a small team of dedicated engine technicians.
The key internal components are individually chosen to form a matching, balanced set so that the engine runs perfectly smoothly – a skill that takes years to perfect. Once completed, and after thorough testing, the engine is signed off by one of Bentley’s engine specialists, as it has been for decades.
The advanced modern-day 6¾-litre V8 combines immense power with impressive fuel economy, developing 395kW and 1,100 Nm of torque in the Mulsanne Speed. This results in a top speed of 305kph and a 0-100kph sprint time of 4.9 seconds.
Original copy and photos supplied by Bentley.