- Features circular plate covering the variable valve timing mechanism on the cam cover
- Will allow the air-cooled motor to comply with upcoming emission norms
- Expected to be introduced in the market later this year
Indian Motorcycle has filed for a new patent application that has been published by the U.S Patent and Trademark Office, suggesting that the bike maker is working on upgrading its air-cooled Thunder Stroke 111 (TS111) engine.
The patent images show a nearly identical TS111 motor featuring the same design. The only visible difference is a circular plate covering the variable valve timing system instead of the Indian logo on the cam cover. On the inside, the overall construction of the engine continues to remain the same. There are two valves per cylinder that are operated by hydraulic roller-rockers. The four pushrods operating the mechanism are matched to three camshafts on the bottom side; two single-lobbed ones for the outer exhaust valves and a double-lobed one located in the centre for the two intake valves. The centre cam arrangement is linked to a cam phaser which advances and retards the valve timings and is controlled by the engine’s control unit. The design also has provision for some amount of the exhaust gases to travel back into the intake manifold in the form of exhaust gas recirculation for better emissions and efficiently.
By upgrading the engines to use variable valve timing technology, Indian will be able to comply with the upcoming emission norms and continue using its air-cooled Thunder Stroke 111 motor. Expect the American bike maker to introduce the VVT tech in its TS 111 powered motorcycles later this year.
