The Bonnick Cycle Company of Coventry, England was formed in 1890 as a bicycle manufactuer and was soon acquired by William Riley Jr. who, in 1896, incorporated a company to own it named The Riley Cycle Company Limited. Percy, Riley's middle son, left school that year and soon began experimenting with automoibles. His first automboile was built in 1898 and featured a mechanically operated inlet valve. The vehicle's construciton was done in secrecy because his father did not approve, but the world's fascination with the horseless carriage prevailed, and by 1899, Percy had moved from producing mtorocycles to his first prototype four-wheel quadricycle. While most other motorized veicles of the era used vacuum actuated inlet valves, it is believed that Percy continued to use mechnaically operated inlet valves. Benz later developed and patented a mechanically operated inlet valve process of their own and tried unsuccessfully to collect royalties on their system from British companies. British automakers persuaded the courts that their system was based on the design pioneered by Percy and pre-dated those of Benz.
The bicycle business was profitable and William Riley was reluctant to divert resources into motor cars. By 1903, after brothers Victor, Percy, and younger brother Allan Riley had pooled their resources and borrowed additional funds from their mother, formed the Riley Engine Company of Coventry. This enterprise was later joined by the other two Riley brothers, Stanley and Cecil after they left school to join their elder brothers.
The Riley Engine Company initially supplied engines for Riley motorcycles (their father's business) and another local motorcycle manufacturer, Singer. Soon, the Riley Engine Company entered the four-wheeled automobile market, building what is considered the first proper Riley car in 1905. By 1907, the company had ceased motorcycle production and focused solely on motorized vehicles. Bicycle production also ceased in 1911. The following year, the Riley Cycle Company became Riley Limited as William Riley focused on becoming a wire-spoked wheel supplier. William Riley's abandonment of his motor-bicycle and automobile business meant his sons' Riley Engine Company had just lost their principal customer.
In 1913, Percy and his brothers Victor, Stanley, and Allan re-focused their endeavors on building entire automobiles. Their first model, dubbed the 17/30, was introduced at the London Motor Show. During the 1920s and 1930s, the Riley company grew rapidly as they proudly proclaimed 'As Old As The Industry, As Modern As The Hour.' The company's existence would endure for over four decades before they were acquired by the Nuffield Organization. During that time, they built innovative vehicles that were invariably sporting and durable. The Riley 9 engine designed by Percy was a small-capacity, high-revving unit with Hemispherical combustion chambers and inclined overhead valves. Its twin camshafts were positioned high in the cylinder block with valves operated by short pushrods. The product names were equally imaginative and creative, with sedans dubbed Merlin and Falcon, or referencing exotic locations like Biarritz or Monaco. The Kestrel referenced a rakish and aerodynamic design with a swept-back tail, while the Alpine or Gamecock were used for open touring cars.
The MPH was introduced in 1935 and just 16 examples were built. They represented the culmination of the company's experience and the ultimate evolution of the competition Riley. At its heart was an overhead valve engine with roots that date back to the company's twin-cam 9hp models first offered in 1926. It was a compact four-cylinder unit with a displacement of 1,087cc and a huge success for Riley, remaining in production for the next decade with approximately 10,000 examples sold during that time. The 9hp was tunable, attracting legendary racers and engineers such as J.G. Parry-Thomas and Reid Railton. Their racing specials were named after their home turf, the Brooklands model.
The Riley Brooklands rested on a short chassis and wore aerodynamic bodies with a tapered rear. They had a shorter radiator and two bucket seats installed inside the frame and just half a foot from the ground. Modifications to the engine brought about 50 horsepower at 5,000 RPM thanks to high-compression pistons and special cams. The prototype Brooklands Riley was taken to the Brooklands Automobile Racing Club Race in 1927 where it easily outpaced the field with an average speed of over 91 mph.
In 1928, Riley began offering a six-cylinder model called the 14/6, which was essentially the 9hp four with two additional cylinders. Like its predecessors, it was not long before competition versions followed, such as the TT (Tourist Trophy) which had incredible racing careers. Catalog production sports models for the mid-1930s were the MPH, TT Sprite, and the 9hp Imp. It is believed that all sixteen of the MPH cars were acquired by privateer racers.
The Riley MPH wore lightweight aluminum coachwork over a traditional ash frame. The twin-cam 2-liter inline-6 engine drove through a Wilson 'Pre-Selector' four-speed semi-automatic gearbox. The suspension used semi-elliptic leaf springs and braking was handled by four-wheel drums.
by Dan Vaughan