Abstract: Embodiments of the disclosure provide variable valve timing (VVT) mechanisms. A VVT mechanism according to the disclosure can include: a lever having a first end, a second end, and a fulcrum positioned therebetween; a length-adjustable push rod coupled to the first end of the lever and including an actuator therein; a rod valve coupled to the second end of the lever, the rod valve being configured to open and close an intake valve of an engine system based on a movement of the lever; and an engine control unit (ECU) operatively connected to the actuator of the length-adjustable push rod, wherein the ECU adjusts a length of the length-adjustable push rod based on an operating condition of the engine system. In addition or alternatively, the ECU can control an amount of cushioning fluid for the valves to affect the rate at which the intake valve opens or closes.