hi there ive been playing with babbingtons for a while, what you need is a car power steering pump, rigged upto a 240/110v motor, they are plenty powerful and can handle some debris in the oil, you only want it turning slow as they will pump quite a bit of oil, i had one off a ford escort and it works a treat, you cant slow the output or it will kill your motor so i did this in the pic below, as you can see the pump runs all day long with the same output, its happiest like this ( i know ive sprayed oil everywhere and cooked motors) and by adjusting the ball valve i can get the oil to either travel straight back to the sump via 15mm copper plumbing pipe or i can close it by a fraction and make the oil run down a length of car brake pipe to the babbington ball, i think a needle valve would be more precise with the flow control, but this works fine and like i said ive run this for 12 hrs straight and no problems at all, hope this helps