BMW M78

The BMW M78 is an inline-6 cylinder gasoline engine produced by BMW from 1933 to 1950. It was a significant engine for BMW, marking their entry into the world of smooth, powerful six-cylinder engines, a characteristic that would become synonymous with the brand.

The M78 was developed from BMW's earlier inline-4 engine designs, expanding upon that foundation to create a longer, more powerful engine. It featured an overhead valve (OHV) design, with a single camshaft located in the engine block operating the valves via pushrods and rocker arms.

The engine was initially introduced in a 1.2-liter displacement, but it was subsequently produced in larger displacements, up to 2.0 liters. It powered various BMW models, including the BMW 303, 315, 319, 320, 326, 327, and 328.

The M78 is particularly notable for its use in the BMW 328 sports car, where its performance contributed significantly to the car's racing success and cemented BMW's reputation for building high-performance engines. While relatively simple in design compared to later BMW engines, the M78 was robust and reliable, contributing to its longevity and the vehicles it powered. It was eventually superseded by more advanced engine designs as BMW continued to innovate and develop new technologies.