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.
Source: Wikipedia — Harley-Davidson engine timeline (CC BY-SA 4.0)