Impeller housing

[TRD]

Hi All,

At the end of the season my impeller went bad. I have ordered a new housing, so my question is could I keep this housing as a spare or is it to far gone? Could I machine the bottom surface? I would need to take out approx: (.010 - .015") to make the bottom surface smooth and flat. The walls are not smooth either, I can make them a little smoother also (not sure if I should do this or not). This would be a very simple process but I was worried about how important the crush on the impeller is. I don't know exactly how the function of the impeller is in and out along the shaft. Is there some clearance in there or is there a crush factor? Would .01 - .015" make a difference.
I really hope I don't have to use this or have this happen again now that I know to change it at the beginning of every season.

TIA
Dale

[mneal]

I am not totally familiar with the impeller housing for your exact type of pump, but all of them are a positive displacement type pump, that means the region occupied by the vanes of the impeller changes as they rotate and cause a pressure drop. A complicated way of saying is if you increase the thrust clearance (machining the bottom surface flat) you will allow that to a be a path for water flow out , thus reducing the efficiency of the pump (will move less water per revolution). Bottom line is housing is toast , unless you could remove an equal amount from the mating surface to leave the depth (thrust clearance) the same as new.

[TeamAllen]

I say, scrap it. You shouldn't need a spare housing. How many years did that one last anyway?

[Jason B]

If you have a new one you shouldn't need that one. If you have to change it on the water you'll likely have a day-ending predicament anyhow.

[TRD]

I am not totally familiar with the impeller housing for your exact type of pump, but all of them are a positive displacement type pump, that means the region occupied by the vanes of the impeller changes as they rotate and cause a pressure drop. A complicated way of saying is if you increase the thrust clearance (machining the bottom surface flat) you will allow that to a be a path for water flow out , thus reducing the efficiency of the pump (will move less water per revolution). Bottom line is housing is toast , unless you could remove an equal amount from the mating surface to leave the depth (thrust clearance) the same as new.

I thought of that but then the oring groove would have to be cut too. That's when I decided against that.

I say, scrap it. You shouldn't need a spare housing. How many years did that one last anyway?

The boat is a 2000. I don't know how long that impeller has been in there. I haven't changed it because I didn't get the boat until the end of the season that I bought it. This is my 2nd year of ownership but really is the 1st year that I have used the boat. I will be replacing the impeller every year from now on anyway.