Harley-Davidson’s Big Twin is the heart and soul of America’s most famous touring bikes. This fall, the icon gets an upgrade.

Last week, H-D unveiled the ninth iteration of the Big Twin, named the Milwaukee-Eight for Harley’s hometown and the eight valves on the new engine (four for each cylinder). With a 50 percent increase in intake and exhaust flow and a revamped cooling system that allows the engine to work harder without overheating, the Milwaukee-Eight produces 10 percent more torque than its predecessor, the Twin Cam, according to Harley-Davidson.
The 107-cubic-inch (1750 cc) Milwaukee-Eight is replacing the Twin Cam on Harley’s 2017 touring bikes, including the Street Glide, Road Glide, Road King, and Electra Glide models. They will start arriving at dealerships around the country this week. The CVO Limited and CVO Street Glide will get the massive 114-cubic-inch (1870 cc) version of the Milwaukee-Eight, and there is speculation that the 107-cubic-inch engine eventually will become the standard on other bikes such as the Heritage Softail. That would be the first rubber-mounted engine on that classic design.
“We want all riders to save the date of September 23,” said Dino Bernacchi, director of U.S. marketing at Harley-Davidson, in a press release. “That weekend, Harley-Davidson dealers across the country will host open house events so riders can throw a leg over our model-year 2017 touring motorcycles and feel the dif...