The silent sports car “3 1/2 Litre” that achieved refinement and speed [Bentley 100 Years of Car History]

3 1/2 Litre Derby

Based on Baby Rolls

Bentley was acquired by Rolls-Royce through the British Central Equitable Trust on November 20, 1931. This surprise acquisition was completed without the knowledge of WO Bentley and other management, and Rolls-Royce promptly closed the Cricklewood factory in 1932. All cars except for a few 8-Litres were sold, and the Bentley trademark was transferred to Rolls-Royce.

WO Bentley himself not only lost his company car, the 8-Litre, but also divorced his first wife. In May 1932, he joined Rolls-Royce on a three-year contract, but was not allowed to approach the development site and was ordered to carry out test drives at Brooklands and on the European continent, effectively confining himself to the company.

Meanwhile, Bentley, which had restarted as a division of Rolls-Royce’s Derby factory, began developing a model based on the 20/25 HP, known as the Baby Rolls, and in 1933 announced the 3 1/2 Litre.

Elegance and luxury, speed and ease of handling

The engine was based on the 20/25 HP 3680cc inline 6-cylinder OHV, but was fitted with a newly designed crossflow cylinder head. By using a special camshaft, an increased compression ratio, and two SU carburetors, it produced 110 HP, exceeding the 20/25 HP. Its top speed reached 145 km/h.

The chassis was basically the same as the 20/25HP, and was equipped with four-wheel leaf springs and brakes with mechanical servos. Another major improvement was that the transmission was upgraded from the D-type crush gearbox of the Cricklewood era to a four-speed manual with synchromesh in third and fourth gears.

When it was first released, the 3.5 liter engine was sometimes described as underpowered, but its high and consistent quality, sophisticated, elegant and luxurious bodywork designed by coachbuilders such as Vanden Plas and Park Ward, as well as its speed and ease of handling earned it the reputation of being a “silent sports car,” and its owner list included racing drivers Sir Malcolm Campbell, Archibald Fraser-Nash and Prince Villa.

Bentley then announced the 4 1/4 Litre, the successor to the 3 1/2 Litre, in 1936. Its greatest feature was the inline-six OHV engine, which had been increased to 4257cc in response to complaints that it was underpowered, and the chassis was also improved with the addition of cross members and the adoption of harmonic stabiliser bumpers.

Two interesting projects

In the end, 1,177 3.5-liter and 1,234 4.5-liter engines were produced by 1939, but WO Bentley left Rolls-Royce in April 1935 when his contract expired, moving to Lagonda with most of the racing engineers and working on the development of the V12 engine.

Around this time, Bentley was also working on two interesting projects. One was the “Embiricos Coupe,” which was commissioned in 1938 by Greek businessman André Embiricos and featured a streamlined body designed by French designer Georges Paulhan and built by Carosier Pourtoux mounted on a 4.5-liter engine. The other was the “Corniche,” a four-door coupe inspired by the Embiricos Coupe and developed by Bentley’s Ivan Everden in collaboration with Paulhan at Vannovolen in Paris.

Both were influenced by the aerodynamic body of the Chrysler Airflow, and the experience gained here had a major influence on Bentley’s post-war body designs.

The reprint project begins

The Corniche was supposed to be unveiled at the 1939 London Show along with the new Mark V chassis, but test driver Percy Rhodes crashed while driving in France. Shortly after, World War II broke out and the London Show was cancelled, so the car was stored in France for a while before being sent back to Britain, but was destroyed in a bombing raid during the Dunkirk evacuation in 1940.

In the 21st century, historian Ken Lee and the WO Bentley Memorial Foundation launched the Corniche restoration project, which was taken over as an in-house Bentley project in 2018, with full-scale work beginning at Mulliner, and was unveiled at Bentley’s 100th anniversary celebrations in 2019.