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 Harley-Davidson engines Engine 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s 2010s Light enginesS1948–1952 One-cylinder engines27.4" F-head1903–190526.8" F-head1906–190830" F-head1909–191235" F-head1913–191837" F-head1921–1923 21" OHV1926–192921" flathead1926–1934 30.5" flathead1929–1934 "Hummers"1948–1966 Topper1960–1965 Baja 1001969–1972 Big twin engines F-head (IOE) 1914–1929 Flathead 1930–1948 (until 1973 in the servicar models) Knucklehead 1936–1947 Panhead 1948–1965 Shovelhead 1966–1984 Evolution 1984–1999 Twin Cam 1999–2017 Milwaukee-Eight 2017– Sport engines W (opposed) 1919–1923 XA 1942 D 1929–1931 R 1932–1936 W (V twin) 1937–1952 G (W engine) 1937–1973 WR 1941–1952 K 1952–1953 KH 1954–1956 KR 1952–1969 Ironhead 1957–1985 XR 1970– Evolution 1986–2022 Fluid (water)-cooled engines Revolution 2002–2017 Revolution X 2013– Revolution Max 2021–
Big Twin (Stock) Engine Sizes: Flathead 45ci (737cc) Knucklehead 60ci (983cc) & 74ci (1212cc) Panhead 60ci (983cc) & 74ci (1212cc) Shovelhead 74ci (1212cc) & 80ci (1310cc) Evolution 82ci (1343cc) Twincam 88ci (1442cc) & 95ci (1556cc) (88/96ci bore 3.75in (95.25mm) & 4.00in stroke on 88ci (101.6 mm) Twincam 96ci (1584cc) & 103ci (1690cc)(96/103ci bore 3.875in (98.40mm) & 4.38in stroke on 96ci (111.25 mm) 2017-Milwaukee-Eight 107ci (1746cc) & 114ci (1868cc) & 117ci (1923cc) 2016-Milwaukee-Eight 114ci (1868cc)
References
Henshaw, Peter, Kerr, Ian, "The Encyclopedia of the Harley-Davidson", 2001, Chartwell Books, Inc., Flatheads, Knuckleheads, Panheads, Shovelheads | A Guide to Harley-Davidson Engines, Devitt Insurance, 2021. Milwaukee 107 Vs 114 [Differences, Reasons & Facts]