Indian seems to be planning production of the Thunderstroke 111 motor with variable valve timing.
Last month, we saw leaked plans for a liquid-cooled big-bore Indian V-twin, probably intended to power touring bikes. Does that mean the Thunderstroke 111 motor is destined for the boneyard? Apparently not, as Motorcycle.com has uncovered patent drawings for a version of the Thunderstroke design with variable valve timing on the intake side.
Variable valve timing is hot in the industry right now, with Ducati including it on recent models, and BMW switching most of its flagship flat twin models over to variable valve timing for 2019, as well as its S1000RR superbike. It has performance advantages, allowing bikes to be fuel-efficient and make power more consistently, but more importantly, it’s great for emissions testing.
Motorcycle.com’s write-up on the patent application (head over there for more photos of the patent) goes extensively into this, and it would indeed make sense if this was the reason for VVT’s inclusion on the Thunderstroke. Air-cooled bikes with big cylinders are notoriously bad in emissions tests, and if Indian wants to continue to make the Thunderstroke, chances are it’ll have to figure out how to lower its tailpipe emissions. What better way than by adding variable valve timing, and maybe picking up some added performance as well?
Overall, the engine seems to basically the same as the current-model Thunderstroke, with the exception of an ECU-controlled cam phaser. That cam phaser can adjust valve timing, which in turn affects the bike’s emissions. As far as serious performance gains, we’d expect those to be found in the new liquid-cooled engine.