A guide assembly for a valve lifter of an engine. The valve lifter is at least partly received within a bore of a body of the engine and an end portion of the valve lifter is exposed to an outside of the body. The guide assembly includes a pin and a guide. The pin is adapted to be fixedly coupled to the end portion of the valve lifter, while the guide is adapted to be coupled to the body. The guide defines a channel. The pin is received within the channel and cooperates with the channel to facilitate a movement of the valve lifter along an axis of the bore and to restrict a rotation of the valve lifter about the axis of the bore.