Harley-Davidson engine timeline

Harley-Davidson engines are a line of engines manufactured since 1903 in Milwaukee, Wisconsin by the Harley-Davidson company for use in its motorcycles. Harley-Davidson engines are now made at Harley-Davidson Motor Company's Pilgrim Road Powertrain Operations facility in Menomonee Falls, Wisconsin.
The company's founders started making smaller flathead motorcycle engines individually by hand and fitted to bicycles in the wooden barn in Milwaukee that was the Harley-Davidson workshop of the time, prior to that in 1901.
That first engine was a single cylinder model, based on the French developed De Dion-Bouton internal combustion engine.
The company was soon fully committed to producing its own proprietary engine designs, and by 1909 the first Harley-Davidson V-Twin engine had been designed and made, setting a template for engine design that continues today.

Engine timeline

Big Twin Engine Sizes:

; References:

Henshaw, Peter, Kerr, Ian, "The Encyclopedia of the Harley-Davidson", 2001, Chartwell Books, Inc.,
, Devitt Insurance, 2021.