1925 Rolls-Royce 20 HP

With the introduction of the Rolls-Royce 40/50 HP 'Silver Ghost, the company switched to a 'one model' policy. Due to the changing times after World War I, the company was eventually forced to abandon the single model policy, and an all-new 20hp car joined the existing 40/50hp Silver Ghost in 1922. Among the changes were a switch from chauffeur to owner-driven cars and the appreciation of a smaller, less expensive, and less opulent automobile. It was an advanced vehicle that was eminently suited to town use yet could cope with Continental touring.

The 'Twenty' highlight's Henry Royce's growing interest in contemporary trends within the American automobile industry. It used unitary construction of engine and gearbox, the latter featuring the modern innovation of a central ball change, and a 'Hotchkiss drive' rear axle. The engine had overhead valves, a first for Rolls-Royce, with six-cylinders and a displacement size of 3,127cc. The cylinders were cast in a single block with a detachable cylinder head, and utilizing both coil and magneto ignition. The engine was backed by a three-speed transmission with central gear change, a setup not well-liked by the motoring public, and when four-wheel, servo-assisted brakes were introduced in 1925, a four-speed gearbox with right-hand, gated change replaced the original three-speed unit. The power produced by the engine was sent to the rear axle via a standard propeller shaft with a universal joint at each end. This setup was unlike the Rolls-Royce power delivery system which relied on a torque tube.

Along with the new inline-six-cylinder engine, later forming the basis in an enlarged capacity for the first two of its Phantom series, the Twenty also moved the gear and handbrake levers to the center of the car. These changes improved access for the driver and enabled practical four-door coachwork to be fitted to the chassis. The handbrake lever change ultimately proved too confusing and within approximately three years, the cars reverted to a right-hand lever arrangement in Britain. In the United States, however, this would be adopted for Springfield built Phantoms.

The chassis used rigid front and rear axles with half-elliptic springs, and a Rolls-Royce radiator with a triangular top was placed in front of the engine. The early chassis examples had a factory price of approximately £1100, and depending on the coachwork, a complete example with coachwork would cost approximately £1600. While some manufacturers produced the entire car, including chassis and bodywork, Rolls-Royce preferred to specialize in chassis and mechanical part construction. The elegant coachwork was left to the most gifted coachbuilders of the era, including Barker, Mulliner, Hooper, Park Ward, and Trupp & Maberly.

During its production lifespan, lasting from 1922 through 1929, Rolls-Royce produced 2,940 examples of the Twenty. They were never built in America, but the new Springfield, Massachusetts factory clearly took orders for the model.

by Daniel Vaughan | Jan 2021