DON’S DAY ONA SUNIIEAM
RATED at 4,000 h.p., weighing four and a half tons and measuring 31ft. lin. from stern to stern, the Sunbeam “Silver Bullet,” with which Kaye Don (at the moment of writing) is attempting an attack on the world’s land speed record, is the most ” special ” of all the monsters that, so far, have been built. The earlier giants were, in a measure, hybrids ; with the “Silver Bullet,” the engines, like everything else in the car, are designed and built specially for their job and the whole vehicle is undoubtedly one of the most interesting things on wheels that has ever been evolved. The engines have twelve cylinders, arranged in banks of six at an angle of 500
. The bore and stroke dimensions are 140 m.m. x 130 m.m. and the capacity is 24,000 c.c. The cylinders are cast in blocks of three and are of aluminium with Nitralloy steel liners. There are four valves per cylinder, and two camshafts for each bank of six cylinders ; one sparking per cylinder is used. At the front of each engine, trains of spur wheels driving the camshafts are housed, and at the back of each there is a multiplication gear to the countershaft beneath the crankcase. The engines are installed in the frame tandemwise. Behind the rear engine is a spur-wheel drive which works a blower. The mixture is supplied by two special Amal carburettors. Lubrication is of the dry sump type and each engine has two pumps. The cooling system is unique ; because an ordinary honeycomb radiator would present too much head resistance, an ice chest and cistern is used in conjunction with water pumps. Ignition is by coil and a battery. Transmission is through a three-speed gear box and two propeller shafts (one on each side of the driver’s seat) and then by straight-tooth bevels to the axle shafts and road wheels. From engine to wheels Brakes are operated on the Lockheed they are almost as large in diameter as the zing fins in the tail of the car. This Springing is by means of straight Steering gear is a duplicated Marks and turning circle of 130 feet. There is no tie-rod
7 he body is very highly stream-lined and the Splintex wind-screen.
the top-gear ratio is 0.965 to 1.
principle, and the drums are situated within the wheel discs ; themselves. There is also an air-brake fitted between the stabilia 21 foot square plate which pivots on a cross shaft.
and Hartford shock-absorbers are fitted.
a lock of only 15 degrees in each direction, giving the car a the front wheels. projects from the main structure save the four wheels and