New Harley-Davidson VVT Engine Under Development
The development is expected to keep big air-cooled motors relevant for at least a decade longer.
Patent images have revealed that Harley-Davidson is working on a new generation air-cooled V-twin VVT (Variable Valve Timing) engine.
This new development model has a twin-cam design, gear-driven from the crankshaft, like other Harley engines, but unlike other motors, it has VVT, with the actuator mounted to the intermediate gear.
It must be noted that the patent has not been filed for the VVT, but rather for a form of crankshaft balancer that’s driven by the camshaft intermediate gear.
In 2019, Indian filed patents for a similar idea with a very similar setup. A coincidence? We’ll let you decide. Also, the VVT actuator is similar to the ones used on Ducati’s DVT system.
There are advantages of having a pushrod engine to which VVT can be added because a single actuator can simultaneously advance or retard valve timing for both intake and exhaust.
However, the patent images of Harley-Davidson VVT engine show that the pushrods are not sited together as usual and rather, a pushrod is present on each side of the engine, there are four in total.
The Harley-Davidson VVT engine patent also shows that the intermediate gear which is driven by the crank is twice the size of the crankshaft gear, thus it turns at half the speed and in the opposite direction.
But, a chain sprocket is also attached to the intermediate gear that runs back to a smaller sprocket (that turns a balancer weight) that is concentric with the crank. This enables the balancer to spin at the same speed as the crank, but in the opposite direction to offset unbalanced forces.
Although the bike in the patent images resembles that of a Fat Bob, it is expected that Harley would plonk the new motor in the Sportster range and not disturb the big V-twins at least in the near future.
Source – Bennetts.co.uk