Bentley Speed Six completes testing program at Goodwood

Now in production, the twelve units of the Speed Six series, Mulliner technicians use materials and techniques from the time, in order to ensure complete fidelity to W.O. Bentley’s original design.

The 6597 cc inline six-cylinder engine of the Speed Six was designed by W.O. Bentley and powered the most successful competition Bentley of the Cricklewood era (1921-31). At the time, it developed about 200 hp, and the Mulliner team made sure to follow exactly the original specifications and drawings, creating the first new Speed Six engine in almost 100 years from over 600 new components, including the engine block.

The Mulliner Classic team had access to the state-of-the-art dynamometers in Crewe and, working with the engineering team responsible for the new 782 hp ultra-performance hybrid powertrain of the Continental GT, developed a continuous 20-hour laboratory testing program, covering a variety of engine speeds and loads. After two test cycles and 40 hours of operation, the new Speed Six engine achieved the defined power and torque goals with complete reliability.

The work on the first units of the Speed Six Continuation Series for clients is now underway at Mulliner Classic, with the first delivery expected in the autumn. Although faithful to the original design, the Speed Six Continuation Series enjoys some advantages. “Today’s tools are more precise than those the Cricklewood factory could have achieved, and we also have the benefit of modern lubricants. During testing, oil consumption was insignificant, even at racing speeds. All Speed Six Continuation Series cars will run well on regular unleaded fuel, and new tires with period tread are readily available,” says Ben Linde, leader of special projects at Mulliner.