Harley-Davidson just took the wraps off of its first all-new motorcycle engine in roughly 15 years. The single-cam Milwaukee-Eight 107 and 114 engines will replace the motorcycle company's twin-cam engine that debuted in 1999. The engine desperately needed to be updated, but the Milwaukee-Eight engine, which is the ninth motor in the company's Big Twin lineage, is a promising alternative.
The benefits of Harley's new Milwaukee-Eight engine reads like an exaggerated résumé: more power, better cooling, reduced vibration, better fuel economy, a better exhaust note, and a slimmer overall design. In other words, the new engine is better in every single way than the previous motor, says H-D. For those wondering, the new Milwaukee-Eight is not backwards compatible with older Harley motorcycles.
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The engine comes in two sizes and three different variations – the Milwaukee-Eight 107 (107 cubic inches, or 1,750cc) and Milwaukee-Eight 114 (114 cubic inches, or 1,870cc). The new engines will be used in Harley-Davidson's touring and trike models. The smaller 107-cubic-inch engine will be utilized in the Harley-Davidson Street Glide, Road Glide, Electra Glide, Road King, and Freewheeler models. The larger 114-cubic-inch engine will power the Ultra Limited, Road Glide Ultra, and Tri Glide Ultra models.
The new engine retains the iconic 45-degree V-twin design, but ditches one cam for twice as many valves – each cylinder now has two intake valves and two exhaust valves – which is where the new moniker comes from. Thanks to a higher compression ratio, larger displacement, and the extra set of valves, Harley claims each engine produces 10-percent more torque than the motor it replaces. Despite the power increase, the new engines weigh the same as the old units, giving the motorcycles better acceleration figures and improved fuel economy, as well.
In traditional Harley fashion, the engines are mostly air-cooled, but have liquid-cooled heads, something the company introduced on its touring bikes in 2014. The twin-cooled 107 cubic-inch-engine has liquid-cooled cylinder heads for the Road Glide Ultra, Tri Glide Ultra, and Ultra Limited models. The larger, 114 cubic-inch-engine features liquid-cooled cylinder heads for the CVO Street Glide and CVO Limited models.
Harley-Davidson will launch the new engines that will be featured in the 2017 model year touring motorcycle lineup through a virtual tour of the motorcycle factory on Facebook Live, which will be a first for the company.