Middletown, NY 10940, USA



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Harley Engines Then and Now

April 8, 2018

So I was curious to learn about the history of the HD engines and their years in use. When I fell in love with Harleys, they were introducing the then new "Evolution Engine". Then the EVO was featured on Mickey Rourke's bike in "Harley Davidson and The Marlboro Man". Yep! I was hooked. The sound that engine made to me defined Harley with the classic sound of "Potato, Potato, Potato" and there was no other bike that could come close to the sound. So Lets take a look at Harleys engines.



1909 The Atmospheric V-Twin 


811cc 45 degree v twin that produced 7HP









1911-1929 F-Head


The first 1000cc motor and had a waterproof ignition. 







 1929-1936 Flat Head


No valves in the cylinder head. They were off to the side to easily remove the heads during service.





 1936-1947 Knucklehead


61ci The rocker covers were re-assembled. The first HD twin to have over head valves.







1948-1965 Pan Head


Aluminum cylinder heads and hydraulic valve lifters. The engine now had improved oil circulation.






1966-1984 Shovelhead


Shoveled out rocker cover designed for original Electra Glide with now 12V electronics.






 1984-1999 Evolution


HD's first engine created using a computer aided design. The engine ran better, used less fuel and made more power and torque.





1999-2017 Twin Cam


The 2nd of the Twin Cam motors available in 88ci, 96ci and 103ci Bigger displacement, more power, better cooling and a more ridged engine and transmission connection.





2017-Present Milwaukee Eight (M8)


New single cam/eight valve air/oil cooled 107ci 1745cc. There are air /water cooled options for touring models. Keeps heads cooler and hides the radiator and fans concealed in the fairing lowers.


If you ask me, I wish I had one of each so I can display them in their own cases in my dinning room! They are definitely cool to look and have their place through out history.


Till next time, keep that rubber side down.

Thank you for reading.

Ivan Rodriguez/ The Cycleshack


Source: John Milbank/MSL








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