scavenge pump flow rate

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BERT said:
From my brief and hopefully enduring observation of this machine, the oil returning to the tank appears to have the viscosity of anything between a frothy latte and maple syrup, depending on temperature of the engine. The main thing is that the oil reaches the furthest points in the system as it is designed to do. It amazes me that a tiny oil pump like this can deliver like it does under sometimes harsh conditions. Thanks for your research efforts.
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Bert, 20w50 in mine. Before I added a Holland Norton Works breather, it was just as you describe. Afterwards, it is now a smooth oil flow, hardly even pulses.
 
Tom Vachon said:
WZ,
I want to get the same oil for my blend but my local Fleet and Farm has nothing called Resolute. They do have a full syn 5w-20 and a syn blend Premium 5w-20.
Could it be that Resolute was terminated? If so which should i use?
Thks, Tom
Click to expand...
WZ,
OK, now i see the problem. Your blend is with Fleet Farm Resolute oil.
I mistook Fleet Farm for Blains Farm and Fleet. We have a Blains but no Fleet Farm in Illinois. Fleet Farm is only in Wisc, Minn, Iowa, So Dakota according to their website. And they wont ship oil to my house, only to one of their stores.
So guess I’ll just blend WD40 with the Blains Farm and Fleet full syn 5w-20.
Do u have a better suggestion that doesnt require me to travel out of state for a quart of oil? Thks, Tom
 
Tom,
I don’t think it would make much difference which one of these oils you use since they are all meeting defined SAE viscosity grades, and we are simply blending low viscosity with high viscosity to obtain an intermediate viscosity. We’re not heating it or cooling it so we shouldn’t be recruiting any of the viscosity modifiers present in the multi-grade oil that could alter the ambient temp viscosity. I’m excited that you’re excited to embark on this next chapter of testing with your rig. Good luck and keep us posted on your findings.
 
WZ507 said:
Tom,
I don’t think it would make much difference which one of these oils you use since they are all meeting defined SAE viscosity grades, and we are simply blending low viscosity with high viscosity to obtain an intermediate viscosity. We’re not heating it or cooling it so we shouldn’t be recruiting any of the viscosity modifiers present in the multi-grade oil that could alter the ambient temp viscosity. I’m excited that you’re excited to embark on this next chapter of testing with your rig. Good luck and keep us posted on your findings.
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Thks again and i will keep u posted!
 
Tom Vachon said:
Thks again and i will keep u posted!
Click to expand...
Heres a lube pmp flow vs rpm plot using a blend of oil and WD40 to simulate a hot oil running condition on a room temp bench test….
Tried various pressures by varying the outlet restriction. Which pressure applies to u depends on how tight your engine is and what pressure your pressure relief valve is set at. This is data from a new Andover pump.
 
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Tom Vachon said:
Heres a lube pmp flow vs rpm plot using a blend of oil and WD40 to simulate a hot oil running condition on a room temp bench test….
Tried various pressures by varying the outlet restriction. Which pressure applies to u depends on how tight your engine is and what pressure your pressure relief valve is set at. This is data from a new Andover pump.
Click to expand...

So with hot oil at 3150 rpm cruise conditions the lube pump is putting out a good liter per minute. Sounds good but lets compare to the human heart.
Web MD and a second site i read states that the human heart, at rest, pumps 5 liters per minute! And, during strenuous activity,up to 20 liters per minute!
Of course the pressure is low, arterial pressure being about 100 mm hg which is about 2 psi. But 20 l/min is 11 oz per second! Now im wondering what the Commando pump puts out at 2 psi resistance……
 
And the human heart has been known to exceed 100yrs without a re-lap service. That said, my Commando looks a lot better than I did at the same age.
 
Intervals are the best conditioning exercise both for my pumper and the Commando oil pump
 
Tom, can you please ask a VIP member to re-post your pictures? I am curious to peruse them.
Despite being posted only few days ago, the pictures appear grey.

-Knut
 
So i did bother to run the lube pump with the blend simulating hot 20w-50 at just 2 psi like our hearts run against. At equiv engine rpm of 3150 the lube pump puts out 1.2 liters/ min. At 900 engine rpm it puts out 0.35 l/min. A little more than it does at the pressures it sees on the bike but not a huge diffwrence. This just shows that leakage isnt much at lower pressures. With a constant displacement pump leakage or cavitation is about all that keeps output from being completely proportional to rpm.
This test at only 2psi was just to compare to our hearts that put out 5 l/m at 2 psi when we are at rest. Up to 20 l/min under strenuous exertion.
Huge apples to oranges, i know, but kinda interesting….
 
mdt-son said:
Tom, can you please ask a VIP member to re-post your pictures? I am curious to peruse them.
Despite being posted only few days ago, the pictures appear grey.

-Knut
Click to expand...

Which posts as I still see the pictures?
 
WZ507 said:
Thanks for sharing all your oil pump testing data.

You made a comment above regarding higher temp testing and the challenges it presents, so wanted to inform that a very close approximation of the hi temp testing can in fact be performed at room temperature (RT). If you had the 20W-50 wt oil at full operating temp (100C/212F) it would have a viscosity in the range of 16-22 cSt. So, if one had a test fluid having a viscosity in this same range at RT, you could repeat your same tests at RT and simulate very closely how the hot 20W-50 motor oil would pump.

The table below shows SAE viscosity of several motor oil grades, thus provides a bit more info to quantify the differences between a range of SAE motor oil grades. The information source is linked below the table.

View attachment 84033

https://www.machinerylubrication.com/Read/23788/motor-oil-viscosity

I have prepared blends of common motor oil and WD-40 to create the low viscosity test fluids referred to above, as shown in the plot below. A blend containing ~ 40 wt% WD-40 in a 5W-20 motor oil would provide a test fluid having a viscosity very similar to 50 wt motor oil at 100C.

View attachment 84034

I’ve used the above described low viscosity test fluid (blend of motor oil and WD-40) several times to evaluate oil pumps from different marques. It is truly astounding how different the collected test streams may look when comparing a RT 20W-50 to a 20 cSt blend. More specifically, the RT motor oil tends to resemble a highly frothed beaker of yellow foam vs the almost bubble-free low viscosity test fluid. Regardless of the results one gets, this approach provides a realistic means of getting much closer to the actual oil pumping and scavenging rates of an engine at full operating temperature.
Click to expand...
Hey WZ, Did u see i used your blend idea and plot? See post #85 of this thread for a lube pump plot using a 38% blend of WD40. Comments?
 
Tom Vachon said:
Heres a lube pmp flow vs rpm plot using a blend of oil and WD40 to simulate a hot oil running condition on a room temp bench test….
Tried various pressures by varying the outlet restriction. Which pressure applies to u depends on how tight your engine is and what pressure your pressure relief valve is set at. This is data from a new Andover pump.
Click to expand...

Hi Tom, I am impressed by your achievements. Your test yields an output of the lube pump of about 1 L/min @ 3150 rpm, 17 cSt kinematic viscosity and 18-19 deg C (65-66 deg F) ambient temperature.
Did you test the old lapped pump using your oil blend, to get rid of the frothing effect? It would be interesting to compare the two side-by-side. I believe reduced gear to housing tolerance accounts for most of the improved flow.

On another note, for the new pump, how much pump shaft leakage is observed at 48-49 PSI and 66 deg F ?

One parameter is missing in your experiments - the oil pump temperature. Some experiments performed by Jim Comstock years ago indicate a markedly improved oil pump efficiency as the operating temperature is lowered, say from 100 to 80 degrees C.
This may have to do with viscosity as well as mechanical efficiency.
Testing a 17 cSt oil (monograde SAE50) oil at 100 deg C and at 80 deg C (at which temperature it will have a kinematic viscosity of about 30 cSt) shouldn't be very difficult and there may be some surprises in store.

- Knut
 
mdt-son said:
Hi Tom, I am impressed by your achievements. Your test yields an output of the lube pump of about 1 L/min @ 3150 rpm, 17 cSt kinematic viscosity and 18-19 deg C (65-66 deg F) ambient temperature.
Did you test the old lapped pump using your oil blend, to get rid of the frothing effect? It would be interesting to compare the two side-by-side. I believe reduced gear to housing tolerance accounts for most of the improved flow.

On another note, for the new pump, how much pump shaft leakage is observed at 48-49 PSI and 66 deg F ?

One parameter is missing in your experiments - the oil pump temperature. Some experiments performed by Jim Comstock years ago indicate a markedly improved oil pump efficiency as the operating temperature is lowered, say from 100 to 80 degrees C.
This may have to do with viscosity as well as mechanical efficiency.
Testing a 17 cSt oil (monograde SAE50) oil at 100 deg C and at 80 deg C (at which temperature it will have a kinematic viscosity of about 30 cSt) shouldn't be very difficult and there may be some surprises in store.

- Knut
Click to expand...
mdt-son said:
Hi Tom, I am impressed by your achievements. Your test yields an output of the lube pump of about 1 L/min @ 3150 rpm, 17 cSt kinematic viscosity and 18-19 deg C (65-66 deg F) ambient temperature.
Did you test the old lapped pump using your oil blend, to get rid of the frothing effect? It would be interesting to compare the two side-by-side. I believe reduced gear to housing tolerance accounts for most of the improved flow.

On another note, for the new pump, how much pump shaft leakage is observed at 48-49 PSI and 66 deg F ?

One parameter is missing in your experiments - the oil pump temperature. Some experiments performed by Jim Comstock years ago indicate a markedly improved oil pump efficiency as the operating temperature is lowered, say from 100 to 80 degrees C.
This may have to do with viscosity as well as mechanical efficiency.
Testing a 17 cSt oil (monograde SAE50) oil at 100 deg C and at 80 deg C (at which temperature it will have a kinematic viscosity of about 30 cSt) shouldn't be very difficult and there may be some surprises in store.

- Knut
Click to expand...
No, sorry i did not test the old lapped pmp with the blend. The new pmp was significantly better than the lapped old one with 20w-50 so i just moved on.
I did get pump shaft leakage even on new pump but just a slow drip. Even at the higher pressures it was not a flow, just some dripping. I didnt bother to try to quantify it. I was impressed with the output of my new pump, esp compared to numbers i found on various forums, etc. I ran many data points at each rpm and overall it was very repeatable. The flow was directly measured by stopwatch timing flow into a marked container. I had a pair of new pressure gauges that agreed perfectley with each other. Several thermometers that agreed well and a digital tack to meas pump rpm. Also the measured data agreed with what the basic press drop formula predicted as func of geometry, flow rate and viscosity.
I think the pump temp was very close to the oil temp in all my runs that were done at room temp in the 65 to 68deg F range. Everything in the room was the same temp. Only the data where i heated the input oil in a shallow baking pan with a hair dryer up to 85 to 95 deg F range would l expct the pump itself to be somewhat cooler.
I would like to run more variations but i had to breakdown my setup. We are now preparing to leave for Florida for the rest of the winter and i have none of my fun moto stuff there. More later, gotta run, time for dinner!
Tom
 
Below are some (hopefully) better quality images of Tom's plotted results. Click the thumbnails to enlarge.

1.) Old Scavenge Pump, Pre and Post Lapping, Room Temp
IMG_0517.jpg

2.) New Scavenge and Lube Pumps, Flow vs RPM, at Room Temp
IMG_0516.jpg

3.) New Scavenge and Lube Pumps, Flow vs RPM, at 85 to 95 deg F
IMG_0515.jpg

4.) New Lube Pump, Pressure vs RPM, Measured and Calculated
IMG_0514.jpg

5.) New Lube Pump, Flow vs RPM, Simulated 212deg F
IMG_0513.JPG
 
WZ507 said:
Below are some (hopefully) better quality images of Tom's plotted results. Click the thumbnails to enlarge.

1.) Old Scavenge Pump, Pre and Post Lapping, Room Temp
View attachment 84399

2.) New Scavenge and Lube Pumps, Flow vs RPM, at Room Temp
View attachment 84401

3.) New Scavenge and Lube Pumps, Flow vs RPM, at 85 to 95 deg F
View attachment 84402

4.) New Lube Pump, Pressure vs RPM, Measured and Calculated
View attachment 84403

5.) New Lube Pump, Flow vs RPM, Simulated 212deg F
View attachment 84404
Click to expand...
Thanks much WZ, they are now nicely titled, organized and much clearer after you click on them. So now any questions can be more easily asked and responded to too.
Im packing right now and leaving for warmer weather early tomorrow, and on the road for two days. So after this evening, i wont be responding promptly, if at all, for a couple days.
Cheers! Tom
 
Tom Vachon said:
Thanks much WZ, they are now nicely titled, organized and much clearer after you click on them. So now any questions can be more easily asked and responded to too.
Im packing right now and leaving for warmer weather early tomorrow, and on the road for two days. So after this evening, i wont be responding promptly, if at all, for a couple days.
Cheers! Tom
Click to expand...
Travel safely. Thanks for sharing your research data.
 
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