What about a oil flow meter??

Lubrication System (oil feed pump and scavenger pump, reservoir, filter, and lines)
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What about a oil flow meter??

#1

Post by Guest »

I have been brainstorming about the oil pressure issues.Since oil flow seems to be more important than oil pressure? What about an in-line flow-meter on the oil return-line?? Just throwing out ideas. Great board!!
FlatHeadSix
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#2

Post by FlatHeadSix »

I've always thought about that myself.

A long time ago the gas pumps used to have a little sight-glass thing with a paddle wheel in it that spun when the gas was flowing. I think it was more of an indicator than an actual meter but it did show that liquid was moving from point A to point B. You could probably find something like that to install in a return line, it wouldn't show how much oil was flowing (like in gallons per hour) but it would show that oil was leaving the scavenger pump and returning to the tank. You would get an idea of relative amount by how fast the little wheel was spinning.

Get busy and find one, let us know where to buy it.

mike
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#3

Post by Cotten »

Pumptesting is something I have studied on Indians, but not H-Ds.
Never needed to...!

But even though they are nearly bullet-proof (excluding aluminum bodies, of course), a study of flow, sump return, and effective pressures could prove of great value.

The first Knucks were proudly announced to deliver a gallon every fifty miles. This was at a time when oil control rings were primitive, over-oiling quickly created carbon, and Indian had already abandoned "total-loss". The 'revolutionary' OHV pump used a 'governor' to minimize flow.
More is not always better!

The best study would be one that eliminates as many variables as possible.
Removing the pump to the bench would make it independent of the motor. Mounting to a vertical plate where it could be driven from the other side by a drill of known RPM is something we could all do, and compare notes.

Attached is a photo of my Indian test bench, where I used plexiglas and drilled it for three different configurations of pumps. It would be a lot simpler for the OHV pump, no doubt.
The feed reservoir is elevated, and the sump draws from tupperware tubs.

If we all use the same oil (50wt seems universal) and aim at 70F (21.1C), and hopefully use the same RPM (a correction graph would be a study in itself), then we would certainly be pioneering some serious forensics. After all, more and more pumps are being used for decades beyond what HD ever drempt they should.

It would be best to know if you had a week pump before you install it!

...Cotten
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#4

Post by Ohio-Rider »

Cotten,
You got way to much time on your hands. LOL
Does your wife know what your doing with her mixer?
Steve
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#5

Post by fourthgear »

You may be able to use a Refrigeration type liquid sight glass . They have them in various sizes , sweat on type ( braze or solder ) and different male and female threaded types. We use them for adj. refrigerant charges and to see if there is moisture in the system . Most are made of solid brass and hold up pretty well to pressure and vibration.
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#6

Post by steve_wood »

Being an electrical engineer, I tend to translate problems into electrical concepts. Sometimes this comes in handy, sometimes (okay most times) it just makes me look like a nerd.

A oil pump can be thought of as a battery in an electrical circuit. It supplies pressure (voltage or "V") to the network of oil passages (resistance - R). The amount of oil flow (current - I) can then be described using electrical formulas.

Remember this from high school?

V = I * R (Voltage = Current * Resistance)

In our oil pump situation, we would have:

Pressure = Flow * Resistance of oil passages

Let's change things around a bit. If V = I*R, then I = V/R. In the oil pump situation:

Oil Flow = Pressure/Resistance

All this to say that the oil flow in a motor is directly proportional to the pressure at the pump. Keep in mind that the resistance of the oil flow circuit will remain more or less constant (the engine doesn't reconfigure itself during operation). The one thing that does change is the viscosity of the oil - effectively lowering the resistance of the circuit - that's why we see less pressure when the engine is hot!

In other words, if you were to install a pressure meter AND a flow meter, the flow meter would rise and fall coincidently with the pressure changes!

So what could go wrong in an oil or electrical circuit? You could have a short circuit which reduces the resistance to zero, making current flow max out. (i.e. an oil leak). You could have an oil blockage, which would make the resistance infinite and oil flow would become zero.

So as long as we trust the physics, then theoretically all we need is an oil pressure guage! We could then diagnose:

- Oil blockages
- Unacceptably low pressure due to low viscosity
- Major oil leaks
- Loss of pressure due to no oil

Note that an idiot light won't tell us if we have oil blockages, but it would tell us the three other problems.

Bench testing is a great idea. But I think we would need some kind of load to simulate the engine. This would allow us to calibrate the system so we could tell if the oil pump is good enough to go on a real engine.

I wonder if there would be a way to simulate the pump operation when the oil is hot? Maybe use a really thin oil to replicate the situation?

Oh well. Time to get back to work.

steve
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#7

Post by 1964 pan »

Wow, that is some cool stuff. Way over my head. Like reinventing the wheel. It is round and it rolls. Good enough for me. Thanks for you brainy guys for keeping me rolling. 8)
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#8

Post by Cotten »

Since I'm a technician and not an engineer, the practical aspects of data collection occur to me first.
We need as much input from as many experimenters as possible. I, for one, cannot spring for rotameters and manometers, nor recording equipment.
But a weight scale and a watch is within reach of all of us, and valves and gauges may be as close as your nearest dumpster.

The volumes and pressures that we are addressing are small, and we want our measurements to be as accurate as possible. Oil has its difficult aspects: Reading volume in a vessel is confused by the nature of it clinging to the sides. Vessels do not empty well. Thus piping the oil into a pre-weighed vessel allows a quick conversion by its density. A stack of paper cups are easily weighed for an average, and a fresh one can be quickly grabbed for the nest sampling.

With the pump bolted to a plate, I hope it will be easy to tap in from the backside to separate the feed entirely from the return.
Let us not forget that the two sides of the pump do not pump under the same conditions. The feed works with cooler oil that has no hydraulic compressibility, but the return deals with a hot bubbly emulsion.
And the return must pump more than the feed by a margin that will prevent over-oiling or highspeed wet-sumping. It must push pressure even on foam!

Although we cannot duplicate the heat conditions (at this time), our collective data at room temps should still give us a valuable guideline.

.....Cotten
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#9

Post by FlatHeadSix »

steve_wood wrote: Pressure = Flow * Resistance of oil passages

Let's change things around a bit. If V = I*R, then I = V/R. In the oil pump situation:

Oil Flow = Pressure/Resistance

All this to say that the oil flow in a motor is directly proportional to the pressure at the pump. Keep in mind that the resistance of the oil flow circuit will remain more or less constant (the engine doesn't reconfigure itself during operation). The one thing that does change is the viscosity of the oil - effectively lowering the resistance of the circuit - that's why we see less pressure when the engine is hot!

steve
Steve,
Your analogy is perfect, I'll expand a little.

As you stated, flow is directly proportional to pressure: more pressure=more flow. According to the formula flow is also INDIRECTLY proportional to resistance: less resistance=more flow. So, theoretically, when higher temps result in lower viscosity you should get more flow.

Mechanical pumps, both gear and vane types, are volumetric. The size of the cavity (space between the gear teeth or size of the chamber created between the pump vanes) is constant. A pump should deliver the same volume of fluid with every revolution. Not considering internal leakage and assuming a constant feed supply, the faster you turn the pump the more it should deliver. The pump is loading and unloading its fixed volume chambers with each revolution. If the chambers don't load or fill completely because of high viscosity (the thick cold oil can't run in there fast enough with its gravity feed) or limited supply (oil tank is empty) this will reduce flow. Same thing if the pump discharge meets resistance, the pump chambers will not unload and the pump will spin with the same oil in its chambers instead of pushing it downstream, the result is the same; reduced flow.

As I mentioned earlier, a paddle wheel spinning in a sight glass in the return line would be a perfect indicator of how much oil was circulating through the engine.

mike
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#10

Post by hjans »

Nice idea, a sight glass. It only takes to change the oil very frequent since the oil turnes black real quick, resulting in a invisable interior of the sightglass.
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#11

Post by FlatHeadSix »

hjans

not just a sight glass, an actual flow indicator. They make them with a brightly colored paddle wheel that wipes the inside of the glass as it spins, it shouldn't matter how dirty the oil gets, you will still see the edges of the colored wheel as they turn inside the glass. most of them are made so that they will not restrict the flow, and pressure drop is not an issue because the oil returns to the tank at amospheric pressure.

It would be neat to actually quantify or measure the volume of flow under various temperature and rpm ranges but I think one of these would give you peace of mind just knowing that there was oil returning to the tank. And, as I said above it would also give you a general idea of how much because increased flow will spin the wheel faster.

something like this

mike
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#12

Post by panhead »

I think it's time to officially found the Panhead Laboratory!
1950Bobber

No shit!

#13

Post by 1950Bobber »

Ohio-Rider wrote:Cotten,
You got way to much time on your hands. LOL
Does your wife know what your doing with her mixer?
Steve
I was thinking the same thing just LOOKING AT HIS CONTRAPTION before I even read your post!!!!!!!!!!!!!!!

You gotta' love these guys....their minds seem so inquisitive...but that's who improve our sport!!!

You're a character Cotten..... (in the good sense, of course!!)
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Re: No shit!

#14

Post by 58Bobber »

1950Bobber wrote:
Ohio-Rider wrote:Cotten,
You got way to much time on your hands. LOL
Does your wife know what your doing with her mixer?
Steve
I was thinking the same thing just LOOKING AT HIS CONTRAPTION before I even read your post!!!!!!!!!!!!!!!

You gotta' love these guys....their minds seem so inquisitive...but that's who improve our sport!!!

You're a character Cotten..... (in the good sense, of course!!)

I think I'l add Flatheadsix AND Steve Wood to my new found genius friends...I love you guys...so inspirational!!!!!!!

I want to play with this too...can I play?
john HD
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#15

Post by john HD »

how about something like this?

http://www.instrumart.com/Product.aspx?ProductID=22928

Image

john
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