Introduced in 1926, Percy Riley's 9hp, 1,087cc twin-camshaft four was an outstanding engine design by any standards, various versions powering Rileys until 1957.

Clothed in stylish bodywork by Stanley Riley, the Coventry marque's pre-war offerings were among the world's finest small-capacity sporting cars.

Percy Riley's proven twin-camshaft layout was retained for the new Hugh Rose-designed 1½-litre four introduced in 1935.

The Falcon saloon made its debut on this new 12hp chassis, which was also available with the familiar Kestrel saloon and Lynx tourer coachwork.

The following year the range was augmented by the Sprite two-seater sports and three more saloons: the Adelphi and six-light Kestrel on the 112.5" long-wheelbase chassis and the shorter-wheelbase (106") all-steel Merlin.

In Standard trim the 1.5-litre 12/4 engine produced 45/46bhp with single Zenith carburettor.

The Special Series came with twin SUs and 52bhp while at the top of the range was the 59/61bhp Sprite specif...