Introduced in 1907, when horses were still the preferred mode of travel and automobiles were loud, smelly and unreliable, Henry Royce and C.S. Johnson of Rolls-Royce, Ltd. unveiled a one-of-a-kind, whisper-quiet 40-50hp legend, the 'Silver Ghost.'
Up to 1906, the most powerful engine Rolls-Royce had ever produced was a 30hp, six-cylinder giant - woefully underpowered considering its seating capacity; there was room to ferry the entire family to the countryside for a Sunday picnic. The company's arsenal of models was powered by two, three, four and six cylinders, and even an abortive V-8 was attempted before Managing Director Claude Johnson's decision to concentrate on the range-topping 40/50 H.P. With a body balanced high over a silky-smooth, transverse leaf spring and a drive-train powered by a huge but silent seven-liter (7248cc), side valve, six-cylinder inline-block, the Silver Ghost broke several world endurance and mileage records. One example was driven on a 15,000-miles test which included driving between London and Glasgow 27 times.
The 40/50 H.P. first appeared at the 1906 Motor Show and became known as the 'Silver Ghost' the following year, when chassis number 60551 was exhibited wearing silver-painted tourer coachwork by Barker. Production would continue through 1926 when it was succeeded by the new Phantom. During its long production lifespan, a total of 7,874 examples were constructed, including 1,701 from the American Springfield factory.
The Rolls-Royce Silver Ghost used a 135.5-inch wheelbase from 1906 through 1913. A 143.5-inch platform was used from 1913 through 1923, and a 144- and 150.5-inch wheelbase were used from 1923 forward. The straight-6 engine displaced 7,036cc from 1906 through 1910 when it was enlarged to 7,428cc. A three-speed manual transmission was used from 1909 through 1913 and a four-speed unit from 1913 forward.
The side-valve, six-cylinder engine had cylinders cast in two units of three-cylinder each. The seven-bearing crankshaft used full pressure lubrication, and the diameter of the center main bearing was larger than the other bearings to reduce vibration. Each cylinder used two spark plugs, and in 1921, customers were given a choice of coil or magneto ignition. Engine output was initially 48 horsepower at 1,250 RPM and later increased to 80 horsepower at 2,250 RPM.
Acetylene or oil lighting was used through the early years, joined in 1914 by optional electrical lighting which became standardized in 1919, the same year electric starting was added.
Early Rolls-Royce Silver Ghost models had rear wheel brakes operated by a hand lever, with a pedal-operated transmission braking action on the propeller shaft. In 1913, the footbrake system moved to drums on the rear axle, and in 1923, four-wheel servo-assisted brakes became optional equipment.