G Rotor vs Gear oil pump, flow meter and pressure comparison.

Bill Miller did a test comparing the two. The results are consistent with what we found after switching to a System One oil pump.

Here's the video.

https://www.youtube.com/watch?v=PDO5bb9_PeE

 

Pretty interesting. I wonder what the Roots lobe type pumps do in comparison to the G Rotor and the gear pumps?

 

gerotor

It looks like the standard RCD/P&P pump that holds numerous records is the gerotor design.
I'm amazed that you can run 12 qts in a wetsump bae at 10500 rpm in the eighth and it lives but it does...Foamy aerated oil is a big deal in the engine and the converter drive.
The BAE wetsump oil system has so many issues IMO the pump is just the tip of the iceberg.
The legal roots cars run the best oil systems that i'm aware of but they are complex and heavy.

 

Well for what its worth and from just the video I would say the P&P Pumps are G-Rotor and the System 1 pumps are Gear style. I think I recall looking at my P&P dry sump I had that it was a G-Rotor as the pieces moved around in an oblong circle like an Enderle pump, And my System 1 is just a gear that spins.

Trevor Sherwood

 

Interesting Subject Pump rpm or crankshaft rpm?

Typically you run a dry sump pump at 50 % crankshaft rpm. Was Bill Miller referring to pump rpm or crank rpm ?

The Peterson pump guys told me to not run over 50 % crank speed (at 9000+ motor rpm) or you will get cavitation with Gerotor system.

My experience is with nat. asp. small block Chev. , at 9600 rpm..... for dry sump, not Chrysler. Volume would be
a requirement for the bigger motor.


I bet the Titan pump guy (Sanders) knows the answers to all of this.

Ray H.

 

Bill spun the pump to 4,500 rpm, just like you would spin a fuel pump on a flow bench. 4,500 pump RPM equals 9,000 RPM at the crank.

What you saw on Bill's screen shots are similar to what I saw on my computer. Beyond 2.5 seconds into the run the oil pressure would flat line and in some cases drop as it headed for the finish line. Near 2.5 seconds the clutch goes into lockup, the engine RPM would run up from 8,000 to 10,500 instantly and at the gear changes it would remain from 9,400 to 10,500 RPM. At the end of the run the oil was aerated from cavitation.

 

I take it, it was Camp Stanley who posted the video? Very interesting tests, and when talking pump rpms I think he's referring to crankshaft rpms to simplify things.

 

System 1 pump in video

I just got off the phone with Bill at BME talking about a set of new rods for my engine and engine oil gpm requirement during a run. He made it clear that the comparisons were done at 9,000 engine rpm. He seems like a good guy and very helpful and honest. He just found a new customer.

 

Cant help but wonder if the g-rotor pumps would do better with the bigger inlet and a an-20 suction line.

 

IT was interesting. He refers to the small pumps. Is there not a big gerotor pump with similar capacity to the gear pump shown?
Now that would be a test because despite the cavitation evidence that big jump in flow with the Big gear pump does kind of mislead the intention of the test.

Dave Koehler
http://www.koehlerinjection.com

 

What style pump would a KB Billet be?
Anyone?

 

I talked to Bill Miller today (Wednesday). He's not done testing oil pumps.

He spun a brand "T" g-rotor oil pump and offered the following "titanic" observations:

-16 inlet line. It reached 30 GPM at 5,847 engine rpm (yes, engine). Above 5,847 RPM it flat lined. Increasing the RPM from this point did not raise the GPM.

He switched the inlet to a -20 line and fitting. Same result. No change. It flat lined at 30 GPM at 5,847 RPM. Increasing the RPM from this point did not raise the GPM.

Interesting these popular pumps are turning out to be RPM limited before going into cavitation.

Any questions or comments, call Bill.


.

 

I have several questions that I would ask regarding this testing. #1, was the flow meter calibrated for use with 60-70WT oil? #2 If not, could there be an issue with the flow meter stalling/reading impropelry due to the viscosity of the oil? If yes, could the internal bypass (pressure regulator) of the pump be bypassing the oil at that RPM? If the flow stops at 30 GPM and it is not an inlet issue or a flow meter issue, what is it? It has to go somewhere!!

 

pressure

Whats the goal? See who can pump the hemi oil system dry the quickest?
The engine only needs a certain gpm of oil. I guess a killer pump would run all the way down track with the relief valve blown open trying to dump excess flow?
I've seen my pressure dropoff when it gets hot at high rpm but there are so many issues with the hemi oiling its hard to say what causes it. Id be really surprised if a bigger gpm pump cured the problem.

 

I agree , but it seems to be the cheapier old style pumps have finally served there purpose . They're outadated now. Yes companies like Titan and system have got it figured out. Caviation kills any engine at any rpm. And we all know if it creates vaccum it's worth hp. So spend your money wisely. And if you can afford the weight put a real dry sump on it and forget about all those problems. That's what I took out of it.

 

whats he testing?

It would be nice to know what hes testing exactly.
The gold gerotor looks like a standard P&P /RCD
He claims a hemi needs 30gpm at 8000 and that pump was done at 18gpm. That style pump in a wetsump application goes 3.60's in the 1/8th at well over 10000 rpm with 3 gallons of oil.
If the test is accurate these cars should be running zero oil pressure under power.
He also stated that a substantial amout of indicated oil pressure is foamy air. I agree. I dont care what pump you have with the standard hemi wetsump you are moving a lot of air.
I find it hard to believe that these gerotor pumps are so inadequate.Nobody has ever bench tested them before?

 

http://www.dragracingonline.com/technical/2008/x_3-gusher-1.html

 

A gear pump cured the problem for me. And it's not just a pressure/flow issue. It's the quality of the oil once it passes through the pump. A cavitating pump is aerating the oil, which still measures in the flow meter. Drained it myself a few times. Bearings and push rods didn't like it at all, and any time the engine saw high C it was rear main time.

 

Did you have the relief all the way in on your g-rotor pump? In the video Mr. Miller states something to the effect of wide open no relief. In the G-rotor article that someone posted above, the G-rotor pump uses the relief to "super charge" it's suction side. The article also states that if the relief is not setup correctly on the G-rotor deal it will cavitate until it breaks itself. Since we are drag racers, oil pressure is good so more must be better. So if we have OK pressure we tend to jack the relief in until we see what we "want", which is more pressure, but at what cost? Does anyone know if he is free flowing the pump or is there an orfice in the end of the #16 to simulate flow through the engine? We don't free flow fuel pumps. Not trying to criticize, I think it's great anytime tests something and makes it available to the rest of us.