In 1906, Rolls-Royce produced four chassis to be shown at the Olympia car show, two existing models, a four cylinder 20hp and a six cylinder 30hp, and two examples of a new car designated the 40/50 hp. The 40/50 hp was so new that the show cars were not fully finished and examples were not provided to the press for testing until March 1907.
The car at first had a new side-valve, six-cylinder, 7036 cc engine (7428 cc from 1910) with the cylinders cast in two units of three cylinders each as opposed to the triple two cylinder units on the earlier six. A three speed transmission was fitted at first with four speed units used from 1913. The seven-bearing crankshaft had full pressure lubrication and the centre main bearing was made specially large to remove vibration, essentially splitting the engine into two three cylinder units. Two spark plugs were fitted to each cylinder with, from 1921, a choice of magneto or coil ignition. The earliest cars had used a trembler coil to produce the spark with a magneto as an optional extra which soon became standard – the instruction was to start the engine on the trembler/battery and then switch to magneto. Continuous development allowed power output to be increased from 48 bhp (36 kW) at 1,250 rpm to 80 bhp (60 kW) at 2,250 rpm. Electric lighting became an option in 1914 and was standardised in 1919. Electric starting was fitted from 1919 along with electric lights to replace the older ones that used acetylene or oil.
The substantial chassis had rigid front and rear axles and leaf springs all round. Early cars only had brakes on the rear wheels operated by a hand lever with a pedal operated transmission brake acting on the propeller shaft. The footbrake system moved to drums on the rear axle in 1913, but from 1923, four-wheel, servo-assisted brakes became optional.
The success of the model led to the company’s dropping the previous range of cars and following a one-model policy until the launch of the Twenty in 1922. In all, a total of 7874 Silver Ghost cars were produced from 1907 to 1926 including 1701 from the American Springfield factory, many of them still running to this day.
After the introduction of the Phantom I in 1925, older 40/50 models were called Silver Ghosts to avoid confusion, but there was only one car given the name “Silver Ghost” – 60551, registered AX-201. The name referred to the car’s ghost-like quietness. For many years after, Rolls-Royce continued with the paranormal theme of naming cars, and the Ghosts remain one of the most evocative symbols of their time.
AX201 at Cat and Fiddle Hill during the Scottish Reliability Trial 1907
1920 Rolls-Royce Silver Ghost limousine