The Bentley was very much larger than the 1368 cc Bugattis that dominated racing at the time, but double the size of engine and strength compensated for the extra weight.

Its weight, size, and speed prompted Ettore Bugatti to call it "the fastest lorry in the world", which was regarded as a compliment.

The four valve SOHC Hemi design, with a bevel-geared shaft drive for the camshaft, was based on the pre-World War I 1914 Mercedes Daimler M93654 racing engine.

[4] Just before the outbreak of the war Mercedes had placed one of the winning Grand Prix cars in their London showroom in Long Acre.

Bentley, then being commissioned in the Royal Naval Air Service, the vehicle was confiscated in 1915 by the British army, dismantled at Rolls-Royce and subjected to scrutiny.

[5][6][7] A notable difference to both the Mercedes and the aero engines was the cast-iron monobloc design, and the fully Aluminium enclosed camshaft, which greatly contributed to its durability.

In the winter of 1926/7 the factory's service department created the first supercharged Bentley when chassis number 220 FR5189 had a Roots type blower fitted to its 3-litre engine.

Like the later 4½ litre supercharged cars its blower was crankshaft-driven and mounted in front of the radiator between the dumb irons.

[10][11][12] An original, unrestored 1927 3 Litre Speed Model (Red Label), chassis #1209 DE, is a part of the permanent collection at the Simeone Foundation Automotive Museum in Philadelphia, PA, USA.

The car retains all of its original components and is the only Bentley to compete in pre-war road racing competition in the USA.