Abstract: A water pump for an internal combustion engine includes a body, a driving shaft held rotatably in the body, an impeller fixed on the driving shaft, a volute chamber formed in the body and including a deflecting portion adapted for introducing a coolant to an outlet port, a chamber formed in the body on a back side of the impeller and including an inner circumferential portion and an outer circumferential portion, and at least two ribs disposed so as to connect the inner circumferential portion and the outer circumferential portion of the chamber, one of the ribs disposed adjacent to the deflecting portion of the volute chamber, whereby inibiting foreign matters contained in the coolant from being left in a space formed between the inner circumferential portion and the outer cicumferential portion of the chamber. When foreign matters are contained in the coolant and when the foreign matters intrude into the chamber, the foreign matters collide with the ribs.

Abstract: An air cleaner for intake air of an internal combustion engine wherein one end of a pressure balancing tube connected to a space confined within a crank case of the engine communicates with to an air cleaner outlet chamber space from which the intake air for the engine is taken out through a main port, characterized in that a port communicating with said one end of the pressure balancing tube is positioned to border on said main port.