Which is my inlet port?

One frequently asked question is which port is the inlet and which is the outlet. Most Sherwood rubber impeller pumps are bidirectional, so the rotation of the engine and the orientation of the pump mount will determine which port is which.
In general there is a cam screw between the ports. That screw holds the cam in place; the function of the cam is to squeeze the impeller as it rotates over it. As the impeller moves away from the cam, the impeller blades open up and water is ingested in the pump (pump INLET). As the impeller approaches the cam and becomes compressed, the water is forced out of the pump (pump OUTLET).

Special Cases: N10360GX - picture shown. The two inlet ports and two outlet ports are next to each other. In this case if the pump were rotated clockwise from this view, the ports would be outlet, outlet, inlet, inlet from left to right.
Special Cases: D55, D60, D65 and all other double pocket (four port pumps). The inlets are on one side of the pump and the outlet on the other side of the cam. Again, locating the cam and knowing which way the engine is rotating is the key. As the impeller moves away from the cam, the impeller blades open up and water is ingested in the pump (pump INLETS). As the impeller approaches the cam and becomes compressed, the water is forced out of the pump (pump OUTLETS).
Special Cases: Integrated Cam Design. Integrated cams are those which do not have a typical removable cam. The cam is part of the housing and the location of that area is necessary to identify the inlet and outlet ports. The smallest span between the ports is where the cam is located. Once located and the rotation of the engine is known, the same identification of the ports descibed above applies to integrated cam, as it would with a cam and cam screw type.