The Internet’s keenest patent spies have uncovered pieces of a design for a new Harley-Davidson engine, just as you’d expect.
For just over a year, we’ve known about a new V-twin platform coming from Harley-Davidson (that’s supposed to be a DOHC system, and not what we’re seeing in this patent). That’s not even taking into account the current Milwaukee Eight engine, which will surely have an expiry date forced on it by emissions regulations. Progress marches on, and even the Sportster’s EVO engine will see its day come sooner or later. Even the Street platform has been out a few years now, and although it’s young by Harley-Davidson standards, it will no doubt see a refresh in the near future. Geopolitics and changing pollution standards will require it.
So what exactly is Harley-Davidson covering with this patent? According to Motorcycle.com, who spotted the patent, it’s an arrangement for a valve bridge system, on a V-twin with four-valve heads. Two valves are operated by a single pushrod; Harley-Davidson has a pushrod on each side of the cylinder, unlike the current configuration, which has pushrods on only one side of the cylinder.
The purpose behind the new valvetrain design is to enable a higher-revving valve bridge configuration. This is interesting, as other manufacturers are moving towards supercharging for the opposite reason: they want to lower revs, to avoid creating more blow-by. Is this a case of Harley-Davidson adopting odd design principles, in order to stick to the V-twin configuration? We’ll know more when the new engine debuts.
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