BMW R32 - the original boxer
In 1923, BMW's first in line crank with two horizontally opposed air cooled cylinders boxer engine, the R32, was designed by German mechanical engineer Max Friz. Friz was the key contributor of engine design and innovation that led to the founding of Bayerische Motoren Werke AG (BMW) in 1917.
BMW oriented the boxer engine with the cylinder heads projecting out on each side for cooling as did the earlier British ABC. The R32 also incorporated shaft drive.