What you are looking at above is Harley-Davidson’s ninth iteration of its “Big Twin” engines. It’s called the Milwaukee-Eight, named after Harley-Davidson’s home town and the fact that the engine head design employs a very modern eight valves in total (four per cylinder head).
Time will tell if the Milwaukee-Eight becomes as iconic as Harley-Davidson’s other designs, like the Flathead, Knucklehead, Panhead, etc. But, we do know that the Milwaukee-Eight marks a more modern approach to engine design from the Bar & Shield brand.
To this end, Harley-Davidson says that the new power plant offers a quicker throttle response, more passing power, purer sound (whatever that means), and a smoother ride (read: less vibrations).
The Milwaukee-Eight will first be used on Harley-Davidson’s touring and trike lines, though we can expect the engine design to permeate through Harley-Davidson’s lineup.