Riley 12/4 History

The Riley 12/4 used a 1½-litre (1,496 cc) four-cylinder engine — a twin-high-camshaft design in the Riley idiom — in a range of saloon and tourer bodies through the mid-to-late 1930s.

Its engine and engineering were the direct ancestor of the post-war 1½-litre Riley RMA, providing continuity from the independent 1930s company into the Nuffield era. Sources vary on the exact span (the 12/4 engine dates to 1934, the model line is usually given as 1935–1938, and it was rebadged the Riley 1½-litre from 1936); it is treated here as the mid-1930s 1½-litre four.