Oil system myths

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mygasser said:
the oil is sucked from the pan as it is a positive displacement pump. here's one of many simple explanations readily available online Oil Pumps
as opposed to how a centrifugal pump works https://www.dultmeier.com/technical-library/how-does-a-centrifugal-pump-work.php
neil.
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So if oil pumps don’t operate off creating a lower pressure on the intake side of the pumps than when a drag car does a wheel stand there is no oil pressure till the front wheels hit the ground in the case of a BB or Hemi or SB Ford? And rock crawlers do without oil pressure as long as the pumps un covered? The spinning gears create negative pressure on the inlet side. Now you believe what you want to believe. As a hydraulic engineer for or 19 years, I’ll go with my beliefs. Done over and out.
 
SGBARRACUDA said:
So if oil pumps don’t operate off creating a lower pressure on the intake side of the pumps than when a drag car does a wheel stand there is no oil pressure till the front wheels hit the ground in the case of a BB or Hemi or SB Ford? And rock crawlers do without oil pressure as long as the pumps un covered? The spinning gears create negative pressure on the inlet side. Now you believe what you want to believe. As a hydraulic engineer for or 19 years, I’ll go with my beliefs. Done over and out.
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It’s going to be a hard sell to convince anyone that these pumps, carbs, vacuum cleaners and a whole host of other tools and such work off of pressure differentials.

It has been taught so wrong for so long it’s damn near impossible to fix it, especially when magazines and YouTube all teach it wrong.
 
A engine oiling system is leaking from the time it leaves the pressure side of the pump. It leaks around main bearings, rod bearings, lifters, rockers. Just cause you have 70 psi at the discharge side of the pump does not mean you have 70 at the rockers. Imagine fighting a structure fire with a 1 3/4” 200’ long line that is figured to flow 200 GPM but along the way hose is full of holes and the couplings are loose. Just because you have the discharge gauge set at 180 PSI Doesn’t mean your getting 200 GPM out of the nozzle! Same with a engine oiling system. Biggest difference is the engine oil system is designed to leak.
 
Hmm. Just to summarize my feelings:

1) Cavitation is cause by the fluid pressure reaching the vapor pressure of the fluid and vapor bubbles forming. Look up the definition of cavitation.
2) I've never seen an automotive oil pump that is not a positive displacement pump.
3) ANY oil pump can "suck the pan dry" if the oil return flow to the pan is less than the oil pump discharge flow.
4) All pumps create a low pressure area at their suction. But the maximum pressure differential is the pressure at the surface of the fluid minus the pump suction pressure. That's why for water the maximum theoretical suction lift is 32 feet from an atmospheric supply.
5) I'm no small block guru but the few engines I've disassembled from 60's era 273's to mid 70's 360's, none of them had oil pump base gaskets.
6) Looking at the SB timing chain oiling variations over the years I have no idea which version is superior. To me the recessed #1 cam bearing on a B/RB/Hemi is a better system.
7) If you have a HV pump, and you have less oil demand than pump capacity, the pump pressure is going to rise until the pump relief opens. So you are recirculating oil from the pan, through the pump, and back into the pan. This does nothing but consume horsepower and increase the load on the intermediate shaft/gear.

There, I'm done spouting.
 
yellow rose said:
It’s going to be a hard sell to convince anyone that these pumps, carbs, vacuum cleaners and a whole host of other tools and such work off of pressure differentials.

It has been taught so wrong for so long it’s damn near impossible to fix it, especially when magazines and YouTube all teach it wrong.
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When you suck on a straw, how do you think the fluid travels up the straw? Magic?
 
And I can NOT post a link to the webinar. You have to be signed in to hear it.

So I will see if I can post a link where all theses webinars can be accessed.
 
How do explain oxygen getting in your lungs? You can’t grab a hand full of it and place it in your mouth? Your diaphragm moves downward, your auxiliary muscle in your chest wall expands your chest and all this creates a negative pressure causing the 14.7 atmospheric at sea level makes the air around us rush into our lungs. And life results.
 
I actually don't understand the whole pressure differential argument going on here. and I'm too lazy to go back and try to dig it out. Is someone arguing that suction doesn't occur or?

On the dry pan issue, I think we can all agree that running a quart or two low will result in a deficit of oil available for the pickup to suck. So it's fairly easy to see how changing to a HV/HP pump can create a similar mismatch. In other words, it turns an adequate sump into an inadequate sump.

In recent engines, when I've used a HV pump I've swapped the spring out to the standard part first. I think the added capacity (volume) is OK....the added pressure, more debatable.
 
gregcon said:
I actually don't understand the whole pressure differential argument going on here. and I'm too lazy to go back and try to dig it out. Is someone arguing that suction doesn't occur or?

On the dry pan issue, I think we can all agree that running a quart or two low will result in a deficit of oil available for the pickup to suck. So it's fairly easy to see how changing to a HV/HP pump can create a similar mismatch. In other words, it turns an adequate sump into an inadequate sump.

In recent engines, when I've used a HV pump I've swapped the spring out to the standard part first. I think the added capacity (volume) is OK....the added pressure, more debatable.
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I can agree with you on this no problem
 
The argument is that pumps don’t produce pressure, which is true. Pumps produce flow. The restriction to that flow is what creates the pressure. Also true. The question is does that mean they don’t create vacuum on the inlet side. The answer is no they don’t “create” vacuum. Remember an oil pump produces flow. The vacuum is a result of that flow. So it’s semantics and an argument not worth having.
 
Since we're talking oil system myths...
Some people say, when the bypass opens oil just gets 'dumped back into the pan'.....FALSE. At least on big-blocks. There's only one way in, and one way out of the pump. Bypassed oil just recirculates within the pump itself.
Is it the same on small-blocks though, or is there a passage back into the pan for bypassed oil?
 
beanhead said:
Since we're talking oil system myths...
Some people say, when the bypass opens oil just gets 'dumped back into the pan'.....FALSE. At least on big-blocks. There's only one way in, and one way out of the pump. Bypassed oil just recirculates within the pump itself.
Is it the same on small-blocks though, or is there a passage back into the pan for bypassed oil?
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Yes. But you can move the bypass out of the pan and make it adjustable but that’s a PITA and only worth it if you are making power above 8000 RPM.
 
SGBARRACUDA said:
When you suck on a straw, how do you think the fluid travels up the straw? Magic?
Click to expand...

It is pushed up the straw by the atmospheric pressure pushing on the surface of the drink in the glass because you are creating a low pressure area by sucking on the straw. Just the same as when an engine creates a low pressure area at the carburetor and atmospheric pressure pushes air and fuel in. Just like an airplane wing creates a low pressure area on top of the wing and allows higher pressure under the wing to push the airplane up.
 
RustyRatRod said:
It is pushed up the straw by the atmospheric pressure pushing on the surface of the drink in the glass because you are creating a low pressure area by sucking on the straw. Just the same as when an engine creates a low pressure area at the carburetor and atmospheric pressure pushes air and fuel in. Just like an airplane wing creates a low pressure area on top of the wing and allows higher pressure under the wing to push the airplane up.
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Yea someone gets it!
 
Correct. But does the wing create the pressure differential? Or does the resulting change in air speed (flow) across the two differently shaped surfaces create the pressure differential? That’s the rediculous argument that is being had.
RustyRatRod said:
It is pushed up the straw by the atmospheric pressure pushing on the surface of the drink in the glass because you are creating a low pressure area by sucking on the straw. Just the same as when an engine creates a low pressure area at the carburetor and atmospheric pressure pushes air and fuel in. Just like an airplane wing creates a low pressure area on top of the wing and allows higher pressure under the wing to push the airplane up.
Click to expand...
 
TT5.9mag said:
Correct. But does the wing create the pressure differential? Or does the resulting change in air speed (flow) across the two differently shaped surfaces create the pressure differential? That’s the rediculous argument that is being had.
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Just accepted science. Rediculous?
 
SGBARRACUDA said:
How do explain oxygen getting in your lungs? You can’t grab a hand full of it and place it in your mouth? Your diaphragm moves downward, your auxiliary muscle in your chest wall expands your chest and all this creates a negative pressure causing the 14.7 atmospheric at sea level makes the air around us rush into our lungs. And life results.
Click to expand...

Most people think they have trouble breathing at high altitudes because there is less oxygen in the air . NOT
 
mbaird said:
Most people think they have trouble breathing at high altitudes because there is less oxygen in the air . NOT
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This is why most of the deaths by climbers of Mt Everest die in the Dead zone. A height of 26,247 ft. Where there is not enough Available oxygen.
 
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