BMW M328
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.
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.