Background
Rolls-Royce's 'single model' policy had proved an outstanding success for the company, but immediately after the end of the Great War the recession in the motor trade prompted the introduction of a smaller, cheaper 20hp car to be built alongside the existing 40/50hp Silver Ghost.
Henry Royce's new design incorporated a number of modern features such as overhead valve-gear for its six-cylinder engine, a centre-change gearbox and 'Hotchkiss drive' rear axle, and the advanced newcomer's arrival only served to emphasise the Silver Ghost's Edwardian origins.
However, the 45/50hp model would soon benefit from developments pioneered on its smaller sibling.
Introduced in 1925, the new Phantom (retrospectively called the Phantom I) boasted an entirely new overhead-valve six-cylinder engine displacing 7,668cc and, like the contemporary 20hp model, adopted a disc-type clutch and adjustable radiator shutters.
Its chassis though, remained essentially the same as that of the later four-wheel-braked Silver Ghost, and would continue fundamentally unchanged until the arrival of the Phantom II brought with it an entirely new frame.
Reputedly the last model that Henry Royce designed himself, the Phantom II was announced in September 1929 with deliveries commencing immediately.
The Phantom II employed an entirely new chassis laid out along the lines of that of the smaller 20hp Rolls-Royce.
Built in two wheelbase lengths - 144" and 150" - this new low-slung frame, with its radiator set well back, enabled coachbuilders to body the car in the then modern idiom, creating sleeker designs than the rather upright ones of the past.
The engine too had come in for extensive revision. The PI's cylinder dimensions and basic layout - two blocks of three cylinders, with an aluminium cylinder head common to both blocks - were retained but the combustion chambers had been redesigned and the cylinder head was now of the cross-flow type, with inlet and exhaust manifolds on opposite sides.
The magneto/coil dual ignition system remained the same as on the PI. The result of these engine changes was greatly enhanced performance and the ability to accommodate weightier coachwork.
Highly favoured by prominent coachbuilders, the Phantom II chassis provided the platform for some of the truly outstanding designs of its day and this example carries limousine-with-division coachwork by H J Mulliner.







