The X-Type Rolls-Royce Vulture Aero Engine is not at present in production, but official details now released by the Air Ministry are of interest because this engine seemed to have a great future when it was first produced and might have been developed further had not war conditions made concentration on other types imperative.
The X-type engine owes its name to the arrangement of the 24 cylinders in four blocks of six each on a common crankcase with an angle of 90° between the blocks. It is liquid-cooled and with a capacity of 42.5 liters the largest motor yet made by Rolls-Royce. The cylinders have 5" bore with a piston stroke of 5½". Cylinder blocks, head and coolant jacket are of aluminum, with wet cylinder liners of steel. The crankshaft is carried in seven bearings. Each cylinder has four valves, operated by overhead camshafts, following normal Rolls-Royce practice, and two sparking plugs, two independent screened magnetos being used in conjunction with two separate HT distributors. The centrifugal supercharger has a two-speed gear and delivers mixture through two main trunk pipes, each feeding two blocks of cylinders. The engine gives 1,845 bhp at 3,000 rpm at 5,000 ft with the supercharger in low gear. With the supercharger in high gear, it develops 1,710 bhp at 15,000 ft.
This news clip is excerpted from the "Aviation Abroad" column in the August, 1942, issue of Aviation magazine, vol 41, no 8, p 240.