• Generally, it is noted that the changing the opening & closing times and lifts of the valves at various operating speeds could enhance the fuel efficiency & reduced emission.
• Based on prior arts discussion, several means of controlling the timing and lift of valves have been proposed, however the IC engines are very limited due to difficulties in manufacturing, assembly, size constraints & cost.
• Further, said prior art actuation mechanism are limited to a complete replacement of cam shaft and /or other components in the engine including external or active means.
• Hence, there is a need to mitigate above challenges & provide efficient solution.
• This invention has addressed above issues in efficient manner.

Present invention describes a method of operating a variable valve lift and timing in IC engine.

The method comprising a few steps as mentioned in the smart chart hereinbelow:

• mounting a secondary moveable cam along the cam shaft of the conventional cam, such that the outer profile of the primary cam & inner profile of the secondary cam are matching, & the outer profile of the secondary cam is optimized such that the sliding secondary cam surface presents a different cam profile to the follower;
• operating the secondary cam with a rotary mechanical assembly governor to move the secondary cam slidably axially along the cam shaft on the basis of engine speed,
• mounting a movable collar on the governor with a governor driving pin operatively connecting the movable cam to the governor;

The axial location of the sliding secondary cam surface presents a different cam profile to the follower, such that the changing profile of the secondary cam results in a variable timing & lift of the valves at various operating speed of the engine. (Refer Fig.1)