Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/1505216
RIDE REVIEW I 2023 HARLEY-DAVIDSON CVO STREET GLIDE & ROAD GLIDE P104 Road Glide CVO and Street Glide CVO Engine Having high displacement V- twins out of Milwaukee is noth- ing new, but the little VVT badge at the bottom of the push rods is. Variable Valve Timing has been featured on Japanese and European bikes for years, but the technology has been con - spicuously absent from Ameri- can V-twins. "When we set out to create this new evolution of the Milwau- kee-Eight powertrain, we had three main focus points—weight, efficiency and performance," says Christina Exner, Principal Engineer, Harley-Davidson Motor Company. "We're 39 pound-feet up to 139 from the previous 117 c.i motor. The horsepower now 115, which is up almost 10 per- cent from the 117." Operating on a single cam- shaft, the Variable Valve Timing system moves through 40°of crankshaft rotation, equaling 20° of cam rotation. There's a phaser located between the cam drive sprocket and the camshaft that uses a solenoid plunger to control the hydrau - lics to change the cam timing, with the VVT system helping to improve the fuel economy a claimed three-to-five percent. "We use a very unique phaser that takes advantage of the small number of cylinders were have," continues Exner. "With the two cylinders, we have one event, so to speak, per revo - lution. We get a pretty torquey characteristic. We use the cam torque itself to actuate the phas - er, so we don't need the oil pres- sure from the oil pump. We use that and we have a valve that sits in the center of the phaser that allows us to pump oil be- tween the two chambers of the phaser to advance or retard the phaser. It's very clever system. The single biggest contributor to the performance increase is very likely the camshaft. We're using a very aggressive cam to reach the performance num - bers we're achieving." Liquid-cooling focusing on the exhaust valve area for each cylinder head helps dissipate heat and keep the rider cool (Left) A preload knob on a $42,000-plus motorcycle instead of dedicated electronic suspension is disappointing. The VVT-equipped 121 cubic inch motor is a thing of beauty. (Right) The CVO Street Glide has its fairing mounted to the fork, which means you're steering it as well as the motorcycle itself.