This first small Rolls-Royce car became an instant success and is easily distinguished by the horizontal radiator shutters on all but last few produced. It had a 6 cylinder 3 litre engine with a monobloc cast iron cylinder block and crankcase, and detachable cylinder head. It was better suited to lighter coachwork than the Silver Ghost and later Phantoms.
- Production numbers
- 2940
- Year
- 1922 - 1929
- Engine
- 6 cylinder monobloc with detachable cast iron head. Capacity 3127cc. Overhead pushrod operated valves. 2-part aluminium crankcase. 7-bearing crankshaft with vibration damper. Pressure fed lubrication with relief valve feeding rocker shaft and timing gears. Oil capacity 10 pints.
- Ignition
- Coil with standby magneto standard from 1924. Semi-automatic timing advance.
- Cooling system
- Engine driven pump and fan. Horizontal thermostatic radiator shutters.
- Carburation
- 2-jet type with starting carburettor and automatic air valve.
- Fuel system
- Rear mounted 14 gallon tank with Autovac. Direct-acting gauge on tank. 2 gallons reserve from 1928.
- Transmission
- Gearbox in unit with engine. 3-speed with centre gearchange. 4-speed with right hand gearchange from 1925. Singe dry plate clutch. Open drive propeller shaft.
- Suspension
- Semi-elliptic leaf springs front and rear. Friction shock dampers, hydraulic from 1926 front, 1928 rear.
- Brakes
- Initially rear wheel only, internal expanding drum, separate independent shoes for foot and hand brakes. Front wheel brakes from 1925 with mechanical servo motor driven from the gearbox.
- Steering
- Worm and nut.
- Chassis lubrication
- Oil gun. Part centralised lubrication system from 1929.
The 20hp chassis series A – E are not clearly defined in the Technical Data published by Rolls-Royce. If you need to find out the chassis series of an early 20hp chassis please let us know.