Engineering:Harley-Davidson engine timeline

Short description: none

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 Harley Family started making smaller flathead motorcycle engines individually by hand and fitted to bicycles in the 10 ft x 15 ft 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 roughly on the recently 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 engines
S																																												1948–1952
One-cylinder engines
27.4" F-head				1903–1905
26.8" F-head							1906–1908
30" F-head										1909–1912
35" F-head														1913–1918
37" F-head																						1921–1923
21" OHV																											1926–1929
21" flathead																											1926–1934
30.5" flathead																														1929–1934
"Hummers"																																																1948–1966
Topper																																																													1960–1965
Baja 100																																																																	1969–1972
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–
Fluid (water)-cooled engines
Revolution																																																																	2002–2017
Revolution X																																																																	2013–

Big Twin  (Stock) Engine Sizes:

• Flathead 45ci (737cc)
• Knucklehead 60ci (983cc) & 74ci (1212cc)
• Panhead 60ci (983cc) & 74ci (1212cc)
• Shovelhead 74ci (1212cc) & 82ci (1343cc)
• 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

• Hornsby, Andy. "A Potted History of Harley-Davidson: Part 1 1903-1954". Crewe, UK: American-V. Archived from the original on 2011-02-11. https://web.archive.org/web/20110211051550/http://www.american-v.co.uk/ORIGINAL/heritage/timeline/pottedhist1/index.html. Retrieved 2011-04-04. 
• Mitchell, D., ed (1997). Harley-Davidson Chronicle - An American Original. Publications International Limited. ISBN 0-7853-2514-X. https://archive.org/details/harleydavidsonch0000mitc_u3q3. 
• Henshaw, Peter, Kerr, Ian, "The Encyclopedia of the Harley-Davidson", 2001, Chartwell Books, Inc., ISBN:0-7858-1274-1
• Flatheads, Knuckleheads, Panheads, Shovelheads | A Guide to Harley-Davidson Engines, Devitt Insurance, 2021.

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