Rationale for a patent
Variable valve timing is an innovation in the motorcycle industry. Companies must meet the needs of their customers who are constantly demanding more power and other engine performance. But they must also comply with strict environmental regulations regarding exhaust gases. The VVT system could help here. But Honda is also updating the VTEC system.
VVT – on exit
Patent application published January 3, 2019 by Honda Motor Corp. shows that the company is working on the development of a new VVT system with cam shift technology similar to BMW’s ShiftCam system. Simply put, each cylinder is equipped with four valves, which in turn have two cams per valve. A flatter cam optimizes engine performance at lower rpm, while a steeper cam increases valve opening at peak rpm.
Unlike the current VTEC technology, which until recently was used in the Interceptor VFR800, which activates and deactivates one of the pairs of valves depending on the required power, the new system keeps all four valves active at all times. The system adjusts the valve opening more smoothly, resulting in a much smoother cam transition and power delivery.
VVT is not new. In fact, the concept of adapting the valve opening cycle to vehicle speed and therefore engine rpm dates back to the 1920s. It wasn’t until 60 years later that manufacturers began to take this technology more seriously, and motorcycle companies started playing with various iterations of the VVT. By 1989, Honda had developed its own system: Electronic Valve Timing and Lift Control, or VTEC, featured in the Integra. It took ten years for the system to migrate to a motorcycle, the 1999 CB400 Super Four. A number of manufacturers are currently using variable valve timing technology on high performance models, including Ducati (DVT), BMW (ShiftCam) and Suzuki (SR-VVT).
The new technology must comply with the Euro5 standard and, according to the patent, is being developed for in-line “Fours”… This means that we will most likely see it in a potentially next generation CBR, perhaps 1000RR.
Honda unveils new variable valve timing patent