Colonel Reginald Clive Gallop (4 February 1892[1][2] – 7 September 1960[3]) was a British engineer, racing driver and First World War pilot.

Part of Bentley's duties was to liaise between the squadrons in the field in France and the factory's engineering staff which is how he came to meet Gallop.

The resulting engine, fundamentally different from the Clerget though—for ease of production—alike in the design of the cam mechanism, was running in prototype by early summer 1916.

Although large for its day compared to similar engines from Bugatti, it was its technical innovations that were most noticed.

To increase durability, the iron engine block and cylinder head were cast as a single unit.

[citation needed] Power output was roughly 70 brake horsepower (52 kW), allowing the final Bentley 3 Litre car via a four-speed gearbox to reach 80 miles per hour (130 km/h).

[citation needed] From 1921, Gallop joined "Count" Louis Zborowski at his Higham Park estate.

The Bentley Speed Six was a huge car, which Ettore Bugatti once referred to as "the world's fastest lorry" ("Le camion plus vite du monde").

[10] With financial backing from Dorothy Paget, a wealthy horse racing enthusiast financing the project after his own money had run out,[11][12] Birkin set-up his own engineering works for the purpose of developing the car at Welwyn Garden City, Hertfordshire.

With an engine and car to be developed by Gallop, Birkin engaged supercharger specialist Amherst Villiers.

The huge Roots-type supercharger ("blower") was hence added in front of the radiator, driven straight from the crankshaft.

[15] The original Bentley Blower No.1 had a taut canvas top stretched over a lightweight Weymann aluminium frame, housing a two-seat body.

had never accepted the blower Bentley, but with effective company owner and financial backer Barnato's support,[19] Birkin persuaded "W.O."