Scavenge Pump

[ny_racer_xxx]

I'm working on a F500/600 project and was wondering if any of uz guyz had any experience with using and electric scavenge pump? My thought was to possibly drysump tyhe motor using 2 electric pumps tp scavenge, and the stock internal pump for lube.

CR

[formulasuper]

My Hayabusa engine uses a dual scavenge pump mounted where the water pump normally is and is driven by the water pump drive shaft. I use an electric water pump mounted in the sidepod. I don't know of anyone with electric oil pumps.

[RussMcB]

Just guessing: I wonder if the viscosity of oil would require a big heavy electric pump and therefore everyone always uses a mechanical pump for weight savings. Or maybe because the mechanical pumps have variable pressure related to RPM.

[ny_racer_xxx]

Super, I am familiar with how the 2 stage water pump mounted units work, thanks for the input though.
Russ, do a search for electric scavenge pump, there are several out there from mild to wild. They are used mainly for low mounted turbo's to return the oil back to the pan.
I looked at a couple of 2 stage mechanical scavenge pumps like the unit that Super is talking about on his Busa, they need to be 2+ GPM, so I figured that 2 electric units of 1+ gpm should do it.
Not sure if there is an advantage or disadvantage, but I would think that it takes more power to pump oil than water????

CR

[John Mosteller]

Scavenge pumps don't take that much power to run as they do not have to pump pressure.Normally you have close to two times the volume in scavenge side as you have on the pressure side. So they are pumping air about half the time which takes hardly any power.I would guess that the extra load on the charging system to run electric scavenge pumps would take as much or more power than mechanical scavenge pumps.Plus if you had an electric pump fail you probably would not no it until scavenge tank went dry and you lose oil pressure as a result .Then you may have a rod through the block as your first indicater.With mechanical scavenge pumps and electric water pump a water pump failure would not cause motor damage as quickly and you would have some time to realize the water temp was to high and shut the motor off with no damage.

John

[ny_racer_xxx]

John, I was comparing the water pump off the motor to any type of oil pump. I still would think that a oil pump off the motor would take more power to operate than the water pump. At full RPM that scavenge pump is pumping 100%, same as if the water pump was there. The agrument that it would draw more current therefore loading the alternator, holds true with moving the water pump to electric, mute point. If it were a total loss system, then there's no draw from the alt....
What would happen if the mechanical scavenge pump failed? I'm sugesting 2 seperate electric scavenge pumps on seperate circuits, that's redunacy that you don't have with the mechanical, even if it's a 2 stage. The SPOF or single point of failure would be the drive shaft on the mechanical pump. True, a battery would a SPOF on the electric system, but if you lost battery, the motor would shut off.
Again, I don't know if it would be any cheaper, easier, better, to do it this way, just wondering what people think, and maybe I'll try...

Thanks for the input.....

CR