The original Rolls-Royce Silver Ghost. Courtesy of Rolls-Royce Motor Cars.
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The Rolls-Royce Silver Ghost had a produc-tion run of 6173 vehicles from 1906 through 1925. The company originally called this model the 40/50, after the 40/50-hp six-cylinder engine. The 40/50 tag came from the fact that the horsepower figure came out to 40 for motor tax purposes, which was derived from the cylinder bore dimension using a formula known as the RAC rating. Actual output was determined to be 50 hp, thus the 40/50 designation.
The name "Silver Ghost" was born after Claude Johnson, Commercial Managing Director of Rolls-Royce Ltd. in 1907, took the 12th chassis, and silver-plated some metal parts, and painted the body in aluminum paint, which gave it the look of silver. Although there was really only one true Silver Ghost, future versions of the 40/50 quickly adopted this nomenclature. Public appearances at races and other contests of the original Silver Ghost propelled the company and the 40/50 model to its place in history. In 1910 Rolls-Royce also opened a driving school and had service technicians visit owners to perform maintenance at the owner's house.
The inline six-cylinder engine was a square unit that consisted of two blocks with three cylinders each. The cylinder heads were not detachable but did employ two spark plugs per cylinder. The 1910 engine was a 7.4-L unit with a bore of 114.3 mm (4.5 in) and stroke of 120.7 mm (4.75 in). The compression ratio was 3.2:1. The engine was water cooled with a pump and fan. Valves were mounted on the side but not enclosed. Tappets, valve springs, and valve stems were therefore accessible from the side of the engine. Tappet heads used fiber inserts to help quiet the engine. A machined nickel-steel crankshaft was used along with seven bearings. A pressurized system was used to lubricate the crankshaft bearings, camshaft timing wheels, and cylinder walls. The engine used a coil and magneto.
A cone-type clutch was used with the four-speed transmission. Overall ratios for the gears were 7.67:1 for first, 4.51:1 for second, 2.708:1 for third, 2.174:1 for fourth, and 9.93:1 for reverse. Maximum speed was 135 km/h (84 mph).
The chassis was constructed of pressed steel with tubular cross members. The front axle was forged and had ten-leaf springs. The rear axle was floating and used a three-quarter elliptical rear 13-leaf spring. The wheelbase was 3442 mm (135.5 in) with a track of 1422 mm (56 in). The wooden wheels were equipped with 875 x 105 mm tires on the front and 880 x 120 mm tires on the rear. Curb weight was about 1492 kg (3290 lb).
body panels are made of flexible sheet molded compound. Rear quarter panels are bolted to the structure.
The suspension is a fully independent four-wheel short/long arm system. It is height adjustable at the factory according to specific options and vehicle weight. Forged-aluminum front upper control arms are used along with cast aluminum front/rear lower and rear upper control arms. A transverse composite leaf spring design is used and runs from the one side of the car to the other. Steering is by a Magnasteer II variable effort rack and pinion power steering system. Under this system the steering effort is reduced at low speeds and increases at higher speeds. Steering ratio is 16.1:1.
An active handling system (AHS) operates in concert with the antilock braking system (ABS) and traction control to activate any of the four wheel disc brakes selectively to help counteract oversteer or understeer. The AHS has three settings —one for everyday driving, where all three systems function; off, which disables all three functions; and competition, which disables only the traction control system.
