The Restoration of the Sunbeam 350hp

That led to its triumphant return to Pendine for the 90th anniversary in 2015, when National Motor Museum engineers were permitted to run Sunbeam on the beach for a low-speed reconstruction of its record-breaking run, with Sir Malcolm’s grandson Don Wales at the wheel.

The non-original Albion 35hp van gearbox which had been added to Sunbeam 350hp before it arrived at Beaulieu was always its Achilles’ heel, as it was only designed to handle a tenth of the engine’s power and lacked a transmission brake. By 2020, a fundraising campaign helped to replace it with a Bentley C-type gearbox adapted to fit Sunbeam’s chassis with custom-made mounts – to better handle its colossal 18 litre engine.

The new gearbox was part of a long term project to restore the car to its 1925 specification.  This also required the fabrication of two full length exhaust pipes, a new seat and upholstery, and the re-manufacture of a slightly dropped nose cone and rear wheel spats.

The ongoing project to restore and preserve Sir Malcolm Campbell’s iconic machine was a labour of love for Beaulieu’s workshop engineers.

Having painstakingly rebuilt its complex V12 engine, they triumphantly took this landmark vehicle back to Pendine Sands in South Wales in 2015, for a low-speed reconstruction of its World Land Speed Record 90 years earlier.

However, while the engine was then in fine fettle, the non-original gearbox has always been the Achilles’ heel in this car’s history and has long been the missing part of its puzzle. At some point after World War II, the original gearbox was removed and by the time the Sunbeam became an exhibit at the National Motor Museum, it was fitted with a temporary gearbox from an Albion 35hp.

Only designed to handle a tenth of the engine’s power, this gearbox also lacked a transmission brake – an important part of the Sunbeam’s original brake set-up.

Reinstating a suitable gearbox was a priority for the engineers, as the next stage of the car’s ongoing preservation. With help from the museum’s supporters, a sturdy Bentley C-type gearbox has been sourced and adapted to fit the Sunbeam’s chassis with custom-made mounts. This unit has proven to be well suited to the task of handling the colossal power of the 18-litre V12 engine.

Best of all, this is enabling the engineers to install a robust and historically correct transmission brake and propshaft. Once the full installation was completed, the Sunbeam had a robust transmission its mighty engine deserved.

The 1920 Sunbeam 350hp can usually be seen on display at the National Motor Museum, as part of a multi-media presentation which also features its record-breaking stablemates the 1927 Sunbeam 1,000hp, 1929 Golden Arrow and 1960 Bluebird CN7.