Backwards sea pump
 

Just wondering if anyone has ever tried mounting a merc sea pump backwards...

When you look on the back of them they say the can pump water in either direction.so it should work fine.

Yeah I know. I'm just wondering if anyone has done it. Im doing it regardless so I can put a decent oil pan on the motor. And gonna mount my oil cooler/ p/s cooler off the front bulkhead so I think it will make rigging a little easier.

I don't believe there is a backward to that style of pump. Kinda like a PD pump.

You have to change the inlet and outlet on the pump if you spin it in the opposit direction. They don't pump if you have them backwards. The KPM pumps will move enough water at idle if you plumb them backwards but will heat up with any kind of throttle the merc pump will suck the water out of the motor and pressurize the drive if they are backwards.

I am lost here as are you asking about the water sea pump impeller and housing or the water circ pump on the front of the motor ?

The water circ pump for whomever fYI - They are bi directional as the water circ pump the brass or bronze impeller can pump in either direction but the reason for that is whatever rotation the engine is itself. Lefthand common or some of the inboards are righthand rotation engines.

If you turned the actually water circ pump 180 almost 100 % sure the bolt holes will not line up and or not fit up and under for the GM apps on the front of the motor. Matter of fact I know for sure that on some GM / Marine apps that you could not mount them turned 180 degrees.

The real reason I am lost about what exactly you are asking if in fact - you are talking about sea water pump / impeller housing turning that around completely backwards, what about the pulley and belt, how are you going to install that ? I guess I am totally missing the question sorry.

Sea pump. I don't run circ pump.

I had to change my wording up so it reads a little different from my 1st post. I know what you are talking after I had to think especially now I see about the oil pan post as if you are installing an oil pan with kick outs.

If you have enough front clearance not to put fold over bends in your water hoses input and output hoses from the impeller housing body and if you can line up the pulley and belt perfectly straight, it can be done, but there is a but.

These stock Mercruiser pumps are one way inlet and one way outlet specific. The complete pump turned backwards now runs in the opposite direction so the outlet becomes the inlet and the inlet becomes outlet water directions, I know that's how it would work for the inlets & outlets but would test it 100 % beforehand and I am 99 % sure about it. its always that 1 % u have to worry about. Just saying

These stock merc waterpumps are inlet and outlet specific as I do know that for a fact. Important never change rotation direction of a used impeller and housings - you will have to start with completely brand new parts here.

IMO I would test it first before any lake runs on the water with the new positioned outlet hose in a bucket to see the volume of water flow or not.

I don't really see an issue on the inlet side guys run 90 degree fittings on them all the time. I was gonna use a 180 degree fitting on the inlet. My only concern was the mounting. I don't have a block in front of me. I was gonna use two head studs with aluminum spacer tubes to mount the pump just wasn't sure if the belt will hit the spacers. I don't think it will. That's why I was asking if anyone has done it.

You can run the pump backwards. Same housing and impeller used on reverse rotation inboards, just switch the hose routing. Never seen it done but can't see why it wouldn't work.