Harley-Davidson Revolution Max 975T Engine First Look: 8 Quick Facts
There’s a new powertrain from The Motor Company: the Harley-Davidson Revolution Max 975T. It first appears in the new 2022 Harley-Davidson Nightster and is part of the redesign of the iconic Sportster line. Let’s take a look at the new engine, which is closely related to the Revolution Max 1250 used in the Pan American 1250 and Sportster S.
- The Harley-Davidson Revolution Max 975T is a short-stroke V-twin design. The 97mm bore is matched with a 66mm stroke to create a pair of combustion chambers displacing 487.7cc. Put them together in a 60-degree V-twin configuration and you have a 975cc engine, rounded to the nearest cubic centimeter.
- Each cylinder head had a pair of overhead cams. Not only is the engine a DOHC design, but the intake cams have variable valve timing. The 975T isn’t your grandfather’s pushrod Sportster engine—it’s even liquid-cooled.
- Although it’s a short-stroke setup with dual overhead camshafts, there’s no need to over-rev to produce power. Torque peaks at 70 ft/lbs at just 5,000 rpm, while it hits 90 horsepower at 7,500 rpm. Harley-Davidson claims “a torque curve that stays flat across the wide powerband.”
- While Harley-Davidson is known for the pulse of its engines, the Revolution Max 975T has counterweights. A Harley-Davidson insider tells us that the counterweight smooths things out, although the engine “holds back just enough vibration to make the bike feel lively.” According to Harley-Davidson, the balancer improves engine reliability, while allowing for a more comfortable ride.
- The Revolution Max 975T is a rugged, stressed-element design. In the case of the Nightster, the engine is part of the chassis.
- Service intervals are extended by hydraulic valve clearance adjustment. Put those feelers away for the most part and let the magic of a hydraulic lifter do most of the work for you. If you like the clatter of valves, prepare for some disappointment.
- The new engine supports electronic driving aids. The first iteration includes power modes, traction control and electronically controlled engine braking.
- Expect Harley-Davidson to use the new Revolution Max 975T in several future models. External tuning can be achieved by changing the lengths and shapes of the intake velocity stacks, as well as changing the size of the airbox. Internally, the cams are certainly fair game for optimizing the engine for different applications.
Photography by Daniel N. Johnson and Buddy Wilinski