10 Key Differences Between Harley’s Milwaukee-8 & Twin Cam
We’ve only had the Harley-Davidson Milwaukee-Eight news posted here for a few hours and y’all are already picking our brains for more info on the thing. Good! It means you want to know what the hell’s going on. Here’s more information on the new motor and how it’s different than that Twin Cam powering your current Harley.
- Baggers Only: At least, for now. New Milwaukee-Eight engines will power every 2017 Harley-Davidson Touring and Trike motorcycle model. The Milwaukee-Eight will be offered in two displacements and three variations: Milwaukee-Eight 107 (107 CID, 1750cc) featuring precision oil-cooled cylinder heads for the Street Glide/Street Glide Special, Road Glide/Road Glide Special, Electra Glide Ultra Classic, Road King/Road King Classic and Freewheeler models. There’s a Twin-Cooled Milwaukee-Eight 107 (107 CID, 1750cc) featuring liquid-cooled cylinder heads for the Ultra Limited/Ultra Limited Low, Road Glide Ultra and Tri Glide models. A Twin-Cooled Milwaukee-Eight 114 (114 CID,1870cc) featuring liquid-cooled cylinder heads powers the CVO Limited and CVO Street Glide models. Dyna and Softail models will keep the Twin Cam motor.
- More Power: Each Milwaukee-Eight engine produces 10 percent more torque than the engine it replaces in Touring models. In addition to increased displacement, the Milwaukee-Eight features 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 contribute to more-efficient combustion. A single chain-driven camshaft is lighter, mechanically less complex and creates less friction and noise. (The Milwaukee-Eight offers similar power in all global markets) “The Milwaukee-Eight retains the classic Harley-Davidson 45-degree V-Twin design,” said Alex Bozmoski, Harley-Davidson Chief Powertrain Engineer, who led the Milwaukee-Eight development team. “It also retains the power characteristic that is the real legacy of the Harley-Davidson Big Twin: strong low-end torque with a broad, flat power curve through the mid-range that’s ideal for the Touring motorcycle rider.”
- Quicker Acceleration: The Milwaukee-Eight weighs the same as the engines it replaces, so all of its extra power contributes directly to improved acceleration performance. The Milwaukee-Eight 107 accelerates 11 percent quicker 0-60 mph and 11 percent quicker 60-80 mph in top gear than the Twin Cam High Output 103. The Milwaukee-Eight 114 accelerates 8 percent quicker 0-60 and 12 percent quicker 60-80 than the Twin Cam 110.
- Improved Economy: Efficiency gained in Milwaukee-Eight air flow and combustion, including the use of dual spark plugs per cylinder, delivers to up to 11 percent better fuel economy, depending on displacement and model, and a corresponding increase in range.
- Heat Management: The Milwaukee-Eight offers improved rider and passenger thermal comfort due to reduced heat absorption, increased heat rejection and a redesigned exhaust system. Each Milwaukee-Eight engine features a precision cooling strategy based on the specific demands of the motorcycle model, using a targeted flow of either oil or liquid coolant around the hottest areas of the cylinder heads. A new knock sensor for each cylinder enables more-precise timing control. The rear exhaust pipe is re-positioned and the exhaust catalyst is relocated to move heat away from the passenger. Idle speed is lowered from 1000 rpm to 850 rpm.
- Improved Fit: A new, 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 models are fitted with an Assist and Slip Clutch with increased capacity and new hydraulic actuation that reduces clutch lever effort by 7 percent.
- Reduced Vibration: The rubber-mounted Milwaukee-Eight engine features a single internal counter balancer that cancels 75 percent of primary vibration at idle for a more-refined feel and more-comfortable experience for rider and passengers while retaining the classic character of Harley V-Twin engines.
- Richer Exhaust Note: Lighter valves, a single camshaft, optimized cover designs and improved driveline components eliminate mechanical powertrain noise. The engine intake and air cleaner are designed to limit intake sound while ensuring maximum air flow. As a result, the new Milwaukee-Eight is mechanically quieter, enabling a richer exhaust tone, and meets global noise and emissions standards while allowing the unmistakable rumble of its exhaust note to resonate.
- Improved Charging: The Milwaukee-Eight charging system delivers 50 percent more output to the battery at idle to better support the power demands of Touring riders, including accessory lighting, performance audio, and heated gear and other accessories.
- New Engine Styling: The Milwaukee-Eight exhibits sleek, modern styling that respects the heritage of previous Harley-Davidson Big Twin engines. “The Milwaukee-Eight is styled to project power,” said Brad Richards, Harley-Davidson Director of Styling. “I compare it to the back of an Olympic swimmer, lean in the waist but broad and muscular in the shoulders.”
To experience the transformation of the 2017 Harley-Davidson Touring models for yourself, visit h-d.com/testride to schedule a test ride.
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