Total Production: 75 1934 - 1935 One of Riley's most successful early model was the Riley Nine. It had an unconventional overhead valve cylinder head engine with hemispherical combustion chambers. The valves were actuated by separate intake and exhaust camshafts located on each side of the block well above the crankshaft centerline. The valves, resting on a 90-degree angle, were operated through short vertical pushrods and shaft-mounted rocker arms. This lightweight valve train and direct valve operation helped earn the Riley Nine around 20 international Class G Records by 1931. This included records that covered distances from 50 kilometers to 3,000 miles, and from one hour to two days with speeds of 64.37 mph to 108.9 mph. Many of these records were earned by legendary driver Captain G. E. T. Eyston.
The Riley Imp was in production for only a short period of time, amassing just 75 examples. Though few in numbers, they did earn a reputation for their performance in road races, rallies, trials, and speed competitions. The Imps featured dual carburetor performance engines and Riley's excellent 'Silent Third' manual transmission, though many were specified with optional Wilson pre-selector gearboxes.
The Riley Imp was given Riley-built steering, cable-operated brakes, and a 1.1-liter four-cylinder engine that offered 50 horsepower. By Daniel Vaughan | Jan 2009