The BMW M328 is an overhead valve straight-six petrol internal combustion engine which was produced from 1936 to 1940. It was a high-performance development of the BMW M78 engine, and was produced alongside the M78.
Unlike with the M78, the M328 has an aluminium cross-flow cylinder head with hemispherical combustion chambers.
The M328 was used in the BMW 328 and BMW 327/28 coupes.
After World War II the engine was also licensed to Bristol Cars in the United Kingdom.
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Design The M328 has an unusual valvetrain design. The single camshaft is mounted low on the side of the engine block, and drives a rocker shaft on the intake side of the cylinder head through a set of vertical pushrods. A second set of horizontal pushrods run in tubes across the cylinder head to another rocker shaft on the exhaust side of the head. This results in a valve layout similar to a DOHC engine.
With a bore of and a stroke of , displacement is ; the same as its M78 predecessor. Fuel is supplied via three Solex 30 JF downdraught carburettors.
The M328 engine has a compression ratio of 7.5:1 and produces at 5000 rpm.
Versions Version Displacement Power Torque YearsM328 at 5000 rpm at 4000 rpm 1936–1940
Applications: 1936–1940 328 1937–1940 327/28 1947–1950 HH
See also BMW List of BMW engines
References Notes
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