dkw racing engine of the s i remember reading about a dkw racing motorcycle engine with three cylinders but one combustion chamber in essence the two outside cylinders were mounted vertically and formed a twingle or split single unit while the middle cylinder was mounted horizontally facing forward in the frame had a larger bore and a smaller stroke and was essentially a supercharger for the other cylinders does anyone have any documentation for this engine i think the motorcycles it powered were successful racers at the time