Harley-Davidson has come out with a new, more powerful engine, ninth in the lineage of the company’s Big Twin engines. The Milwaukee-Eight engine should offer quicker throttle response, more passing power, purer sound, and a smoother ride than its predecessors. New Milwaukee-Eight engines will power every 2017 Harley-Davidson Touring and Trike motorcycle model.
“Riders asked us to create a new engine designed to enhance their motorcycle touring experience in every way,” said Scott Miller, Harley-Davidson Vice-President of Styling and Product Development Strategy. “Those same voices also demanded that we stay true to our legacy and respect the defining elements of a Harley-Davidson V-Twin. It was a big challenge, but one we’ve met.”
Stronger and Faster
The Milwaukee-Eight engine produces 10 percent more torque than the engine it replaces in Touring models. In addition to increased displacement, the Milwaukee-Eight engine has a higher compression ratio and four-valve cylinder heads with 50 percent more intake and exhaust flow capacity. The valve train requires no adjustment as the design of the rocker arms enables valve lash to be set at the factory for life. Dual spark plugs for each cylinder and a lighter, quieter single chain-driven camshaft round out the new engine’s features.
While the Milwaukee-Eight engine weighs the same as the engines it replaces, the 107 model accelerates 11 percent faster 0-80 mph, and the 114 model accelerates 8 percent faster 0-60 and 12 percent quicker 60-80 than the Twin Cam 110.
Cooler and Smoother
Due to a redesigned exhaust system, the Milwaukee-Eight engine promises improved rider and passenger thermal comfort. The engine meets all global noise and emissions standards. Idle speed is lowered from 1,000 rpm to 850 rpm. The rubber-mounted engine features a single internal counter balancer that cancels 75 percent of primary vibration at idle.
Style and Fit
“The Milwaukee-Eight engine is styled to project power,” said Brad Richards, Harley-Davidson Director of Styling. “I compare it to the back of a swimmer, lean in the waist but broad and muscular in the shoulders.”
“The rocker covers look like skin stretched taut over muscle, like the rocker arms are about to burst out of the engine,” said Richards. “For the first time since the Knucklehead, the rocker covers reflect the action going on below. And they are massive. When you sit on the bike you can look down and see more of this engine.”
A slimmer primary drive cover and the low-profile shape of the air cleaner cover provide improved rider legroom around the engine and an easier reach to the ground for many riders. All Milwaukee-Eight powered models are fitted with an Assist and Slip Clutch with improved hydraulic actuation that reduces clutch lever effort by 7 percent.
The Milwaukee-Eight engine charging system delivers 50 percent more output to the battery at idle to better support such power demands as accessory lighting, performance audio, and heated gear and other accessories.