The BMW M337 is a straight-6 OHV petrol engine installed at a slanted angle which was produced in three variants (M337/1, M337/2 and M337/3) from 1952-1958.

Built to power BMW's first new car after World War II, the M337 engine was a replacement for the BMW M78.

Compared with its M78 predecessor, the M337 features a revised cylinder head, a new inlet manifold and a reinforced crankshaft with bigger, more modern bearings.

[1]: 88 [2] As per the M78, the M337 has an iron engine block, an iron cylinder head and overhead valves with two valves per cylinder.

[3]: 46 The first version of the M337 engine has a displacement of 120.3 cu in (1,971 cc).