Production began again in earnest after World War One with copies of the US engine being manufactured by Hotchkiss of Coventry. One major difference between the two engines was that the Coventry built model had a cork clutch that ran in oil, one of the few contributions Morris made to detailed engine design!
The early 1930s were poor years for Morris, and 1933 witnessed the appearance of the 1.3 litre 10/4. Morris hit the production jackpot again with his 918cc Series 1 Eight of 1935, a season in which, incidentally, he offered no less than 32 different models! The Eight continued in production until 1938, by which time 250,000 had been built, making it the best-selling car of the decade. It was replaced for the 1939 season by the Series E Eight with completely new bodywork and faired-in headlamps. Although the Eight was Cowley's best-seller, the Morris range at this time boasted four other models, ranging from the 10/4 to the 3.5 litre 25. All, with the exception of the Eight, were fitted with ohv engines. 1939 was also a significant year for Morris in that the Series M 1,140cc Ten marked the company's first foray into integral construction.
The immediate post-war years saw the reappearance of the pre-war Eight and Ten, though a major landmark came in 1948, with the announcement of the Issigonis designed Minor. Initially powered by the 916cc Series E engine, and featuring torsion bar ifs, rack-and-pinion steering and 14-inch road wheels. It remained in production until 1971 and was the first British car to sell over a million examples. The ohv Austin 803cc engine from the A30 was fitted from 1953 and the capacity progressively increased to 1,098cc.
The sv 1,476cc Oxford and series MS Six, powered by an ohc 2.2-litre engine, also appeared at the same time as the Minor, and shared similarly styled bodywork. The creation of the British Motor Corporation in 1952 by the merging of the Austin and Morris companies inevitably resulted in rationalization, with the Cowley and more powerful Oxford receiving ohv Longbridge engines in 1954, the former 1,200cc model appearing the same year. By 1959, the appearance of the Farina bodied 1.5 litre saloon meant that the differences between the Cowley and Longbridge products were less marked.