Turbo Electric Oil Feed and Scavenge Pumps

Turbochargers should be positively scavenged. If you can do it mechanically like we have done in many installations over the years, then the expense, packaging and complexity of an electric pump is not necessary. If you have a poorly designed scavenge system or none at all then an electric gear pump is your best alternative.  We've been dealing with these issues for way over 30 years.


Turbocharger oil scavenging has always been an issue. You might have 50 psi feeding the turbo but the slightest restriction in the "drain" will immediately send oil past the exhaust seals. In the case of remote mounted turbo systems, or in systems mounted below the engine oil level, some form of positive scavenging has to be engineered. Typically this involved belt driven scavenge pumps from companies like ARE (Avaid), Moroso, Stock Car Products, Peterson , Barnes and others.

Some people like STS (Squires) Turbo, Callaway, Lingenfelter and others use auxillary scavenge systems either mechanical or electric. If you have any sort of drain issue you are going to have oil going past compressor and exhaust seals. The slightest restriction will cause immediate "oiling".

A brief look at how this has been handled by RB Racing and others can be helpful in solving turbocharger issues.

History...Dry Sump Wet Sump

RB Racing has, for more that 28 years, engineered out solutions for turbo oil feed and scavenge systems. Early SOHC Hondas had the pen-ultimate dry sump systems that were bullet-proof. Later on, all the motorcycle engines went wet sump which mixed up clutches, transmissions and everything in the same oil bath. Harleys remained dry-sump systems but, with roller bearing crankshafts, were low pressure designs with lousy dry sump capability and leaking check balls that routinely filled the lower end with oil.

Hondas, with their plain bearings, had excellent oil pressure and you could not kill the turbos due to the superb design of their dry sump oil systems. Oil pressure bypass and back-flow valves were incorporated in the design. We still see 30 year old CB750 SOHC Hondas running around. Early Kawasaki and Suzukis had roller bearing cranks and had problematic turbo feed and drain problems due to low oil pressures and a propensity to send debris to the turbocharger bearings. This lead us to separate electric oil feed systems.

In any of these systems the rider had to avoid stupid mistakes like having the turbo spinning 180,000 rpm and then suddenly killing the engine and pulling in the clutch to do a "plug check". Bye bye turbo bearings.

In the early 1980s we used to put close tolerance Weldon 8000 series 12v electric vane aircraft transfer pumps on our race bikes to feed or scavenge the Rajay and IHI turbochargers. The pumps were extremely sensitive to debris and, if manually activated, were subject to rider brain fade which resulted in destroyed turbocharger bearings when the rider forgot to turn on the pump before a burn-out began. Then came the phone call..."Your turbo went bad". They all lie.

Above is a Weldon Tool 8000 series pump that we used to use. Customers were fond of tearing them up. Our competitors bought a few from us and then we told them to just buy them from Weldon. Model 9200 vane pump pictured below.We moved on. Last we checked these pumps were $892.00...

Clean oil. We tell people the turbo has to be free of debris and they routinely pipe unfiltered oil to the turbocharger. Filters clog or bypass oil when things are cold and all the crap goes to the turbocharger. Don't pump any debris through these.

Oil Scavenge....Mystery Era 1985 Up

Lay on the floor for four to six months taking oil pans on and off. Plumb sensitive Magnehelic gauges into various cavities. Take oil pans on and off hundreds of times on different bikes. Drench yourself in oil. Machine parts. Remachine parts. Make complicated custom internals, mill fixtutres, cad programs. Test and retest. Bring the parts to market. Then for the next 20 years have people call you on the phone saying they have copied your designs and they want to "buy the oil system". Sell a turbo kit to a customer. He creates a website to tell of his speed conquests and implies that he designed the parts and will tell everyone how he designed the oil system. He never does. He has no knowledge.

Watch the Result (Movie)


Mechanical system that is really difficult to make. We won't go into the details even if waterboarding is authorized. However if you have certified proof that you have waterboarded Dick Cheney we might talk to you.

For People Who Couldn't Figure it Out

Tilton has a differential oil pump that people have resorted to who gave up trying to buy "Just the Oil System" from us. Usually it was the Suzuki crowd. Flojet makes pumps like these. These are diaphragm pumps not spur gear nor gerotor pumps. They were never designed to hot pump oil. They work, but there is always a question. 2135 series.

Shurflo makes a similar diaphragm pump that has been used for scavenging of oil on turbochargers. These also were never designed to pump hot oil. 8000 series. One of the people we dealt with in the past has attempted to make a mail order business out of selling these for three times the cost after he gave up trying to figure out our mechanical scavenge system on the Suzuki GSXR series. He tried to pry the information out of us for more than a year. We told him to go sling hamburgers as this would be closer to his engineering expertise. These are not spur gear nor gerotor designs.

German VDO Pump

VDO has a pump (part # 4050400010001) that was used primarily to send engine oil to an oil cooler. Expensive. Don't ask us where to get them. They are prone to failure in scavenge situations as they were really designed to pump non-aerated oil to coolers.

Real Oil Pumps Use Gears

Jim Feuling has passed on but his oil pumps are still keeping Twin Cam Harleys running better than the oem part. This is gerotor design as opposed to the normal spur gear. Take apart any new Japanese bike and you will find gerotor pumps submerged in their wet-sump systems. They offer smooth oil delivery which is directly related to the number of teeth. They work best submerged, not lifting oil.

Virtually most oil pumps use some form of spur gear design. It's cheap. It works, and it's really good at scavenging oil where it is not submerged in the sump. Tolerant of much abuse, it is a time tested design. Some Harley aftermarket pumps use spur gears to scavenge the crankcase and gerotors to pump the oil. There is a reason for this. VW pump pictured. Straight cut gears are more "noisy" than helical cut so we use helical cut gears.

RB Racing Electric Spur Gear Oil Feed and Scavenge Pumps

Bronze helical (quiet) gears. Bronze pump body. No diaphragms to fail. Gear design for maximum scavenge. 12Vdc with splash resistant wiring. Silicone seal Weatherpack connector. Proven in years of use. Metric thread O-ring boss seal (3/8" BSPP) on pump body. 3/8" NPT male entry and exit. Pumps 03-1034 left and 03-1035 Super right pictured above.

These pumps are suitable for remote turbo systems as oil scavenge pumps. In this case the engine supplies the oil pressure and the pump simply returns the turbo oil to a point above the sump level. They are also suitable as turbo oil feed pumps where gravity drain is possible and are often used where a separate turbo oil supply is used which keeps engine oil and turbo oil separate.

The pump should be mounted vertically as shown above as there is a shaft seal between the pump section drive shaft and the electric motor. Other orientations can be used but are not suggested. Mounting the pump vertically with the pump section facing "up" is a definite no no.

Two pumps are available, Standard and Super. The Standard and Super have the same pump gears, the only difference being the Super pump has a stronger electric motor. Larger just means it's longer and larger in diameter and more powerful. The Super pump is rated at 3 gallons per minute whereas the Standard is rated at 2.6 gpm.

If Used For Oil Feed

If used for pressure feed,both pumps will pump up to 40 psi or greater but the Super pump is rated at 40 psi constant whereas the Standard pump is rated at 25 psi constant. Trying to runs higher pressures will overload the pumps and burn up the motors. It's a question of the torque required.  Keep in mind that turbos do not need 3 gallons per minute feed, so to prevent overworking the pump motor the oil must be by-passed back to the feed side of the pump or to the oil reservoir. Typically this is done in a "Tee" fitting after the pump discharge with an AN4 feed to the turbo and an AN6 bypass line with an orifice restrictor to the oil reservoir. All pumps must be fused @ 10 Amps.

Garrett GT series ball bearing turbos only need about 9 to 30 psi of oil pressure so their flow rates are less than plain bearing units.

03-1036 Check Valve on Pump Exit

Pumps are available with a viton seal backflow 1 psi check valve (03-1036) with 3/8" NPT female fittings for oil scavenge applications. This is installed on the pump discharge port and prevents oil from backflowing into the pump section.

Turbo Oil Feed Check Valve

A 1/8 NPT, 1 psi viton seal check valve (03-1039) is available for the turbo oil feed port. This prevents capillary bleed-down of oil in the engine from entering the turbo after engine shutdown. We also can supply a 1/4" female NPT, 25 psi viton seal check valve (03-1047) for high pressure oil feed lines on Garrett GT series ball bearing turbos to drop oil line pressure 25 psi. This also serves as a capillary bleed-down prevention.

03-1047 25 PSI Oil Pressure Reduction Valve

Reduces line pressure by 25 psi. Used where line pressure is too high for both plain bearing and ball bearing turbochargers. On very high pressure systems with ball bearing turbochargers these can be used in conjunction with an oil restrictor fitting on the turbo inlet. If idle oil pressure is 45 psi then 20 psi will be the turbo feed pressure.  If peak oil pressure is 70 psi the turbo pressure will be 45 psi. On plain bearing turbochargers pressures above 65-70 psi oil tends to get by the compressor and exhaust seals. Ball Bearing Garrett GT series turbochargers only require 9 to 30 psi. Above 30 psi and flow rates can go by both compressor and exhaust seals.

Fittings: AN6/8/10 and 3/8" Hose Barb Options

All pumps can be ordered with special O-Ring sealed 1/2" and 3/8" hose barb fittings. The cost is an additional $15.00 per fitting or $30.00 for two. Keep in mind with barb fitting you have bend radius considerations with hoses.  03-1034 pump shown with 1/2"Barb Fittings.

We recommend that pumps be fed with 1/2" ID lines (AN8).

37 Degree Flare AN6, AN8, abd AN10 fittings are available.

Turbo Timer

Timed delay of oil pump turn off insures that the pump action occurs up to 90 seconds after engine shut down. Incorporates internal 30 amp relay. Simple screwdriver adjustment of the time of the delay from zero to 90 seconds. Instructions are available in a PDF format. This is typically used in an oil feed situation where the oil supply continues for a timed period after the engine is shut off. It is not necessary for scavenge unless you also have some sort of timer that keeps the engine running to "cool-down" after you key "off" the ignition.

03-1046 Oil Filter, 03-1034 Pump: Differential Cooler; Oil Feed

Here we have our 03-1034 pump (2.6 GPM) with AN8 exit fitting that would be connected via an AN8 (1/2" i.d.) feed line to a dedicated, separate oil cooler. The 03-1046 sub micron filter on pump inlet keeps the oil clean flowing to the pump and oil cooler. The inlet filter screws directly onto the pump and has 3/8" female NPT ports.

The oil scavenge pump has precise bronze gears. If you send any debris through the pump, it can either jam, or damage the pump gears. Filtering the oil before the pump, if the oil is coming from a differential, is a good idea.

Two Stroke Turbo

There are no end to "projects". Here is a turbocharged, intercooled, two stroke Johnson 56.6 CID engine with water injection. 03-1034 pump and filter supply the turbo with oil. Excess oil is bypassed back to the oil reservoir. Put this on a 13 foot long boat and....Well, we'll stick to two wheels, gears, rubber tires, asphalt, and the Bonneville Salt Flats...although, sometimes, it does flood at Bonneville.

Garrett Oil Pressures

This is the system we use on our Bonneville bike as it keeps the turbo oil and the engine oil separate. As you can see from the chart above the ball bearing turbo we use is well supported by the 03-1034 pump. If you are using engine oil to feed a Garrett GT Series turbo you may need our 03-1047 25 psi check valve to drop line pressure 25 psi.

Fuses...Sealed Weatherpack 03-1042 Option

All pumps should be on a 10 Amp fused circuit. We offer an inline Weatherpack sealed 10 Amp fuse option for $25.00. Failure to run the pump on a fused circuit will cause pump failure if the pump is jammed by debris.

Is In Out? Is Out In? Which Direction?

Since these are DC motors you can simply reverse the leads from the sealed Weatherpack connector, i.e. the red and black wires, to change direction of the pump. This simplifies mounting the pump and running the lines to the "inlet" and "outlet".

“When you come to a fork in the road, take it.” ~Yogi Berra

Typical Use

Everyone wants to go fast and do it themselves. It's often the journey that's the important part.

Customer writes: " I would like to thank you for setting me up with your super scavenge pump 03-1035 for my remote turbo project! I took my 1997 mustang gt and built a twin turbo set-up for it in my back yard. I used your pump for the return oiling. I just wanted you to know how impressed everyone is when they see how well this thing works. I used stainless tubing to help with quality and looks. The set-up completed my project and if it wasn't for the pump set-up my dream would have not become reality.

I drive this car as my daily driver and the pump has worked flawlessly for 12,000 miles now. The car makes 412rwhp and 427ftlbs. to the rear wheels on 8psi. I have enclosed a few pics of my build for you. Thanks for the great product! This winter my goal is to swap out my motor to a built 4v cobra motor and turn up the boost for a goal of 750-1000rwhp. I eventually want to take my daily driver to the salt flats with a goal of 200+ mph. Thanks again I look forward to supporting your business, even my tuner was shocked at the quality of the pump system and loved the idea. Thanks, James M."

Part Numbers and Prices

Item / Descriptiion
Oil Scavenge Pump Standard, 3/8" NPT Male exit/entry, 5 lbs, 2.5" x 5.5", 2.6 GPM (center)
Oil Scavenge Pump Super, 3/8" NPT Male exit/entry, 7.5 lbs, 3.0" x 6.5", 3GPM (left)
Viton Check Valve, Pump Exit, 3/8" NPT, 1 psi scavenge backflow
Viton Check Valve, 1/8" or 1/4" NPT (specify), 1 psi, turbo oil feed line. Bleed-down prevention
Viton Pressure Reduction Valve, 1/4" NPT, 25 psi Garrett GT Ball Bearing Turbos
Turbo Timer 30 Amp, Timer Delay 0-90 seconds
10 Amp Weatherpack (silicone sealed) Inline Fuse Option
Stainless Steel Mounting Bolts, washers, and locknuts (set of 4)
Oil Filter for Inlet of Scavenge Pump, Sub Micron: 3/8"NPT Female
Oil Filter for Turbo Oil Feed Line, Sub Micron: 1/4" NPT Female
1/2" Hose Barb Fitting Option. Per (1) fitting
3/8" Hose Barb Fitting Option. Per (1) fitting
5/16" Hose Barb Fitting Option. Per (1) fitting
Straight AN10 Fitting Option. Per (1) fitting
Straight AN8 Fitting Option. Per (1) fitting
90 Degree AN10 Fitting Option. Per (1) fitting
03-1050 90 Degree AN8 Fitting Option. Per (1) fitting $25.00
03-1044 Straight AN6 Fitting Option. Per (1) fitting $15.00
03-1053 Straight AN4 Fitting x 1/4" NPT 

Note: Some people want to use these pumps on very old motorcycles that have minimal charging systems that will not even support an electric fuel pump. If you do not have enough charging capacity you should not use electric pumps for feed or scavenge.

Note: All pump bodies are 3/8" BSPP straight thread (3/8" x 19) with an O-Ring seal. This prevents cracking the pump housing with an over-tight tapered pipe thread. The O-Ring seal prevents leaks. If the fitting is removed it should have Blue Loctite placed on the threads in addition to the O-Ring seal. As supplied the pumps have 3/8" NPT Male fittings facing outward.

Secondly: You must use #AN8 (1/2" i.d.) or AN10 (5/8" i.d.) on scavenge lines. Using lines below 1/2" i.d. will result in a dramatic reduction in scavenging.


Mike Geokan's Bonneville Bullet. 139" Watercooled ORCA engine. Dry sump engine (Harley) and Dry Sump Oiling system for the larger Garrett turbocharger. Check out Mike's progress as he goes for Bonneville speed records. Viet Nam Vet. Uses 03-1034 electric turbocharger feed pump. Mike has used electric oil pump systems from RB Racing for 15 years.

In this feed situation we use 1/2" inlet hose and a 1/2" exit hose to a "Tee" fitting with AN4 to the turbo and 3/8" return line with a calibrated restrictor to the dry sump tank. Oil pressure is maintained at a maximum of 30 psi to the Garrett Ball Bearing turbocharger. It works well at Bonneville. We run 25 to 28 psi feed.

ORCA Turbo Dash

Read more about these dual egt and boost dashes that we manufacture. We use these on our turbo systems and on our race projects.