BMW M337

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.

Design
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. As per the M78, the M337 has an iron engine block, an iron cylinder head and overhead valves with two valves per cylinder.

M337/1
The first version of the M337 engine has a displacement of 1971 cc. It produces 48 kW at 4,400 rpm and 129 Nm at 2,000 rpm.

Applications:
 * 1952-1954 501

M337/2
In 1954, a revised engine was released which produced 54 kW at 4,400 rpm and 130 Nm at 2,500 rpm. The compression ratio for this engine is 6.8:1.

Applications:
 * 1954-1955 501A
 * 1954-1955 501B

M337/3
The final version of the M337 had an increase in bore of 2 mm, which increased displacement to 2077 cc. The compression ratio was also increased to 7.0:1. Despite these changes the M337/3 produced no more power than the previous version. However torque increased to 135 Nm at 2,500 rpm.

Applications:
 * 1955-1958 501/3