Do you need an electric oil pump?
Engine Oil? Gearbox Oil Cooler? Diff Cooler?
What flow rate do you need?
0.25GPM? 2 GPM? 3 GPM?
Before you buy one, read this...
We have tested most pump brands and most are complete GARBAGE - be warned....
After years of trying all sorts of oil pumps to provide lubrication and cooling for our Differentials and Transfer Cases (with terrible results), we decided to try a new pump on the market, the TurboWerx Mini EXA Pump. The pump looks a bit nicer than most of the others on the market and is fitted with an awesome heat sink.
There are hundreds of 12V oil pumps on the market, sold and promoted by various brands. Many are the exactly the same pump, sold with a different sticker, or the same pump head driven by a slightly different motor, but in principle most are the same concept, flow rate and design.
Some examples are shown below:
Most of the 12V oil pumps are using most basic of pump principles, two gears in mesh.
Look closely and you may see many similarities between all the different brands, but be aware, many have the same components, concepts, and flow rates.
We unpacked our brand new TurboWerx Mini Exa pump and connected it to a test circuit, with a tub of 60 weight motor oil and some short Dash 6 lines and the supplied 140 uM fine mesh filter fitted to the pump inlet.
When we powered up the Exa Mini Oil Pump we noticed immediately the pump was running backwards - Hmmm.... Upon closer inspection the pump was wired by the manufacturer (turboWerx) in REVERSE (Black to Red, Red to Black) - not a good start. :(
After reversing the wires, with the correct polarity power applied the pump, the pump simply created a HUGE FOAMY mess and failed to pump any oil at all. The pump gears were screaming and it was obvious that the pump gears were cavitating (Air in the gears)
With an oil tub full of FOAM now, we started looking for a problem with the pump. We thought that the pump was not actually a self priming pump after all or perhaps it had been damaged running backwards for a few minutes?
We tried funnels filled with oil held up aboge the inlet, we tried filling the suction lines, priming the pump, priming the lines, positively feeding the pump, but NOTHING worked, the pump SIMPLY did not pump any oil - it just made a big foamy mess and pumped a foamy micture of brown oil and bubbles into our oil pan.
After removing the Turbowerx "supplied" 140uM filter, we pulled the filter apart and found the filter mesh media to be so fine that 60 weight motor oil simply CANNOT pass through the mesh, even under pressure, let alone when fitted to the pump suction side.
We then removed the supplied filter from the inlet side of the pump and connected the inlet line directly in to the oil pan and for the first time in 2 hours, the Mini Exa pump started to finally "move" some oil. (the pan looked like a childs bath full of bubbles, but the pump was now starting to dribble a few drops of oil into the pan and starting to circulate oil.)
When we finally got the pump working in the correct direction and no longer blowing bubbles, we noticed once the oil thickened up (All the foam had settled after 30 minutes), the Mini Exa Oil Pump stopped cavitating and was now pulling much much more current than TurboWerx representative and website had stated. We were seeing currents between 8 and 12 amps when pumping at 5 PSI though 12 inch long lines. The motor was getting very very hot, just sitting on the bench, pumping oil around some short lines. The motor quickly reached 75 Deg C (176 F) in a matter of minutes - wow. The test was not looking good.
The TurboWerx EXA and Mini Exa Oil Pumps use a "direct drive" gear, which means the gears are driven at the speed of the motor. Turbowerx state that the EXA pump provides between 2-3 Gallons per minute and the Mini Exa provides 2 GPM - This all sounds ok until we actually tested the pump.
During our bench test the pump got really hot and used a LOT of current and when we connected the pump into our vehicle with the oil flowing through our cooling circuit, things just got worse - really quickly.
When we then connected the Exa Mini pump to our Diff Cooler via our 4 Foot (1.5 metre) oil lines the TurboWerx Mini Exa the pump started to pull more than 18 amps and sounded like it was going to stall completely. The pump started to slow down second by second and sounded like it as running at 10-20 normal speed and we quickly disconnected the power when the motor started to get so hot that we could not touch the motor casing.
We assumed the high pressure was being caused by the oil cooler so we disconnected the oil cooler feed line. Running the Turbowerx Mini Exa Oil Pump through an open Dash 6, 4 foot (1.5 metre) oil line simply created a few drips out of the end of the oil line and the pump still pulled more than 12-13 amps and sounded like it was running at 50% speed, It kept getting slower and slower and HOTTER AND HOTTER.
Whilst the Turbowerx Oil Pumps are indeed designed and promoted to provide a MASSIVE 2-3 GPM flow, we began to wonder - is it even possible to suck 2-3 GPM of oil through a sensibly sized oil liine and then push it through an oil cooler and back to your gearbox, motor or turbo?
Well lets find out:
Using the calculator below (basic Hydraulic Engineering Data Sheet) draw a line from the "flowrate" (LHS) to the flow "flow velocity" (RHS) for each of your oil line types (Suction, or Pressure).
Looking at the chart above, it is CLEAR that any pump needing to suck (pull) 3 GPM will need a Dash 12 or Dash 16 Suction Line and Dash 8 or Dash 10 return lines - FACT
Now remember, this chart is based on "Thin" Hydraulic Oil, so you try to imagine how big your suction line diameter must be to suck/pull 3GPM of Engine Oil, or even thicker gearbox or diff oils through a line at 3 GPM.
We have seen many sites selling pumps for Turbos, Gearboxes and Diffs that have flow rates of 2-3 GPM, but what the hell would a turbo need 3GPM of oil for? We did some investigations and if you read the "fine print", you will see that it is recommended that the user BYPASS most of the pumps 3GPM flow back to the sump (using a Tee Piece/Bypass) and only let perhaps 10% of the flow up to the turbo.
I think most racers would agree that if you ACTUALLY managed to pump 3GPM into your turbo, then your vehicle would have lot of white smoke pouring out of the exhaust because the turbo would simply be overfilled and flooded with oil.
In fact, most power steering pumps only provide 1-3 GPM, and they are driven by your HUGE petrol or diesel engine, using a large rubber belt. Asking a 3GPM pump to be driven by a small direct drive 12V DC motor is a very big demand.
Back to our pump testing:
With the chart above showing flow velocities and recommended line diameters, we then added a pressure gauge to the pump outlet to confirm what was going on and if the recommendations in the chart are correct and or we were experiencing high pressures and low flows due to back pressure.
The TurboWerx Mini Exa Pump created around 40 PSI back pressure, in our free flowing 4 Foot Oil line, BEFORE we even connected the line to our oil cooler. When we connected the oil cooler and a return line into the hydraulic circuit , "BOOM" we saw 55 PSI of pressure at the pump outlet and the pump pretty much stalls out and gets red hot really fast.
In our opinion, the "only" way the Turbowerx EXA or MINI EXA oil pump could suck and then pump 2-3 GPM would be using massive Dash 12-16 suction lines and perhaps Dash 10 pressure and return lines. This is just plain silly, Our NASCAR 6 Stage Dry Sump uses Dash 12 suction lines and a Dash 10 Pressure line.
Most gear pumps advertised to pump "Oil" look very similar to the pump below, keeping in mind the pump below was designed to pump Water, Diesel and Low Viscosity Fuels/Oils. The gear in the Turbowerx Pumps are very large in comparison to the motor size and the maths simply do not add up.
Asking any electric pump to push 3GPM of engine oil is insanity and should be avoided - SIMPLE
Circlips In Your Turbo?
In addition to the high flows, we noticed that when the pump is running the circlip flies around at high speed on the shaft. Have a look at the circlip holding the gear in place in this video we tool. Notice the circlip spinning against the shaft - not ideal at all. The circlip could wear through the shaft, come loose, damage the pump gears and push parts of the gear and/or circlip into your turbo bearings - ouch.
In summary, trying to push 2 or 3 Gallons Per minute of oil through dash 6 or 8 lines, up to a cooler, back to your diff, gearbox or Turbo using a 12V 2-3 GPM Gear Type Pumps (Like the TurboWerx Min Exa or EXA) Oil pump is madness - do not try it. Sure they will push 2-3 GPM through short lines on a bench test, but in reality, when you have long lines, oil coolers and a filters in your circuit, be warned.
You are wasting your time AND MONEY if you want a TurboWerx EXA or Turbowerx Exa Mini pump or any other gear type pump on the market today to push any oil thicker than 5-10 weight viscosity oil reliably anywhere around your vehicle.
Are all the pumps the same?
Looking at the gear design, dimensions and components, it seems that many of the Oil Pumps on the market today, including the TurboWerx Units are pumps that have been maunfactured using components that are commonly found in pumps that were originally designed to pump Kerosine, Diesel, and other low viscosity fuels and oils. Most pumps for sale have similarly high flow rates (Excessive for turbos and diffs) perhaps because they were oringially intended to move Diesel from one tank to another and were NEVER designed from day one for motorsport applications pumping oils around your engine bay or driveline.
The Good News:
We recently have found a hiqh quality positive displacement oil pump that provides around 0.5 GPM and is suitable for our heavy weight Diff Oils and Dash 6-8 lines. We are very happy with the results of our testing of this unit to date and are looking forward to many seasons of racing without stupid oil pump failires.
If you would like to know more about the pump we are now using to pump our gearbox and diff oils into our diff coolers, please contact us.
Again - Follow the Flock, or make an Informed Decision and fix the problem.
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