Rolls-Royce 20 HP

The Rolls-Royce 20 HP built between 1922 and 1929 was Rolls-Royces "small car" for the 1920s and was produced alongside the 40/50 Silver Ghost and Phantom. It was intended to appeal to owner drivers but many were sold to customers with chauffeurs.

A new in-line 6 cylinder overhead valve engine was designed for the car of 3127 cc with a bore of 76 mm and stroke of 114 mm. Unlike the Silver Ghost engine, the cylinders were cast in one block and the cylinder head was detachable. Both coil and magneto ignition were fitted. The early cars had 3 speed gearboxes with the change lever in the centre of the car but this changed in 1925 to a four speed unit with traditional right hand change. A torque tube was used to transmit the power to the rear axle.

The substantial chassis had rigid front and rear axles suspended by half elliptic springs with braking initially only on the rear wheels. Four wheel brakes with mechanical servo were introduced in 1925. The famous Rolls-Royce radiator with triangular top was fitted and early examples had enamel finished horizontal slats later changing to a nickel finish and finally becoming vertical.

In 1920 a chassis cost £1100 with typically a complete tourer bodied car costing around £1600. With coachwork to the factory recommended weight the car could reach 60 mph but many owners had large limousine bodies fitted with the inevitable effect on performance.