Does the filter really alter performance?

[SuperBusa]

Originally Posted By: Gary Allan
Quote:
It doesn't matter if the flow is in a "positive displacement situation" or not. In the simplest terms, if you put pressure on a volume of fluid it flows ... and the more resistance there is to flow the more pressure you need to make it flow ... it's basically that simple.

Show me the equation(s) that only solves for P related to your flow scenario claim.


Okay ..I've determined that you really need this concession after me repeatedly taking all that you've said for granted.

Yes, fluid can not flow without potential/differential. Why you're hung up on this minor player here ..well, it's hard to figure.


No worries ... it's basically semantics as I've said earlier. Everything I've said is true, but it seems to always go against your way of thinking, so you're always trying to "correct" my thoughts in these discussions. Not saying you're thoughts are always right either ... we just both need to realize there are different ways of expressing thoughts on this stuff.

If you look at Bernoulli’s equation, you will see that there are 3 types of pressure head terms: static, dynamic and elevation.

H = (P/p)+(V^2/2Gc)+Z

H = total head
P = pressure
p = fluid density
V = fluid velocity
Gc = gravitational constant
Z = fluid elevation

The total head (H) is the sum of all 3 terms.

The total pressure (Pt) is: Pt = pH

Anyway, if you just look at the dynamic fluid term (V^2/2Gc), you can see that the actual pressure associated with this head term is: P = p(V^2/2Gc).

P, p and V are the only variables, and are all dependant on each other. Knowing 2 of the 3 variables (P, p or V) you can calculate the other unknown. The fluid density (p) and velocity (V) can give you a flow rate knowing the cross sectional area and velocity at that particular point in the flow system.

So, this dynamic flow term essentially boils down to saying that "flow is proportional to pressure". Or in your world of thought, one could also say "pressure is proportional to flow". The ONLY time you can have zero pressure in a dynamic flow situation is when the velocity is zero – then it becomes a static pressure situation. You can obviously have static pressure without flow (defined by the P and Z terms of Bernoulli's equation).

Semantics (and other minor misunderstandings) ... kills a good debate every time.

 

[SuperBusa]

Originally Posted By: LuciferCaitiff

The ADBV is something I've found to be very beneficial in my car (89 Honda Prelude), as I've run a Napa filter and it ALWAYS drained back, causing my oil light to stay on and even blink a couple times every time I start up.


Wow, that's kind of surprising. Was that the NAPA Gold filter, or one of lower priced NAPA filters?

Originally Posted By: LuciferCaitiff
The dumb-guy's explanation I got (because I'm a dumb guy) was that a larger filter gives more surface area for oil to pass through, therefore it passes through at a lower pressure (not much lower I assume), and therefore gives the filter more chance to do its job.


A larger (longer) filter also can hold more contaminates and will therefore not start to restrict flow as much as time goes on. If an engine is producing a lot of contaminates that the filter needs to catch, the larger filter will not load up as fast (in terms of total contaminates per filter area) as if you were using a smaller filter.

My feeling is - use a larger filter is you can. Many applications have a short and long filter that will work, and the cost between them is basically nothing, so why not go long?

 

[LuciferCaitiff]

I dont remember if it was a napa gold filter or a regular one, It's still in my garage. I'll take a look tonight and post if I remember.

I change my filter when the oil gets dirty. Sometimes that's at 3,500 miles, sometimes its at 2,000. Depends on how I drive, really. If I keep the RPMs low I can go farther with cleaner oil, but I have a short 5th gear, 80mph is 4,000rpm. I usually change it around 2,000 miles just cause I want the car to last forever. (255k original build)

I thought about putting the longer filter on my girlfriends prelude, cause she lives 650 miles away from me and does the drive more often. I just didn't feel like doing the modifications this time around. Next time though. I had to cut off that silly 1" bolt head thing off the top and put a spacer in the motor mount to lower it so it would clear the subframe.

 

[Gary Allan]

Originally Posted By: SuperBusa
Originally Posted By: Gary Allan
Quote:
It doesn't matter if the flow is in a "positive displacement situation" or not. In the simplest terms, if you put pressure on a volume of fluid it flows ... and the more resistance there is to flow the more pressure you need to make it flow ... it's basically that simple.

Show me the equation(s) that only solves for P related to your flow scenario claim.


Okay ..I've determined that you really need this concession after me repeatedly taking all that you've said for granted.

Yes, fluid can not flow without potential/differential. Why you're hung up on this minor player here ..well, it's hard to figure.


No worries ... it's basically semantics as I've said earlier. Everything I've said is true, but it seems to always go against your way of thinking, so you're always trying to "correct" my thoughts in these discussions. Not saying you're thoughts are always right either ... we just both need to realize there are different ways of expressing thoughts on this stuff.

If you look at Bernoulli’s equation, you will see that there are 3 types of pressure head terms: static, dynamic and elevation.

H = (P/p)+(V^2/2Gc)+Z

H = total head
P = pressure
p = fluid density
V = fluid velocity
Gc = gravitational constant
Z = fluid elevation

The total head (H) is the sum of all 3 terms.

The total pressure (Pt) is: Pt = pH

Anyway, if you just look at the dynamic fluid term (V^2/2Gc), you can see that the actual pressure associated with this head term is: P = p(V^2/2Gc).

P, p and V are the only variables, and are all dependant on each other. Knowing 2 of the 3 variables (P, p or V) you can calculate the other unknown. The fluid density (p) and velocity (V) can give you a flow rate knowing the cross sectional area and velocity at that particular point in the flow system.

So, this dynamic flow term essentially boils down to saying that "flow is proportional to pressure". Or in your world of thought, one could also say "pressure is proportional to flow". The ONLY time you can have zero pressure in a dynamic flow situation is when the velocity is zero – then it becomes a static pressure situation. You can obviously have static pressure without flow (defined by the P and Z terms of Bernoulli's equation).

Semantics (and other minor misunderstandings) ... kills a good debate every time.

DOOD!!!!!! ... all of this isn't pertinent to the discussion at hand.

NOT ONE BIT. None of that allows you to further the viewing of the flow's impact on the filter in terms of pressure!!

Please, you're wasting your time reciting any of that. It's worthless in "seeing" what occurs.

AGAIN, all you've posted ..CONCEDED TO AND TAKEN AS GIVEN ..even if I can't even read it.

You're never gonna see this using this approach. Now if you REALLY CAN see what I'm saying, then I cannot see how what you're presenting relates to it.


Again, take your formula there ..plug any values that you want for a any of the parameters ..and dump the output into a 12' diameter conduit with a 12' outlet to atmosphere 100' long.

What's the pressure reading just off the pump? 50' out? 90' out.. when the pump output is 1gpm??

I ASSURE YOU ..IT's ZERO!!! there can NEVER be a pressure reading in THE CONDUIT (which is what WE'RE talking about in this WHOLE DISCUSSION).

You're STUCK somewhere else.

 

[SuperBusa]

Originally Posted By: Gary Allan

DOOD!!!!!! ... all of this isn't pertinent to the discussion at hand.

NOT ONE BIT. None of that allows you to further the viewing of the flow's impact on the filter in terms of pressure!!

Please, you're wasting your time reciting any of that. It's worthless in "seeing" what occurs.

AGAIN, all you've posted ..CONCEDED TO AND TAKEN AS GIVEN ..even if I can't even read it.

You're never gonna see this using this approach. Now if you REALLY CAN see what I'm saying, then I cannot see how what you're presenting relates to it.

... Gary, I think Mr. Bernoulli would turn in his grave if he heard you say that his equation doesn't pertain to any of these flow discussions. I assure you, it does apply to oil flow in an engine’s oiling circuit in the simplest terms.

BTW - to be clear, I'm NOT talking about filter flow specifically, but flow in general, but I’m sure it still applies also to filter flow - ya can’t have flow without pressure is what the dynamic pressure term of the equation says).

Originally Posted By: Gary Allan
Again, take your formula there ..plug any values that you want for a any of the parameters ..and dump the output into a 12' diameter conduit with a 12' outlet to atmosphere 100' long.

What's the pressure reading just off the pump? 50' out? 90' out.. when the pump output is 1gpm??

I ASSURE YOU ..IT's ZERO!!! there can NEVER be a pressure reading in THE CONDUIT (which is what WE'RE talking about in this WHOLE DISCUSSION).

You're STUCK somewhere else.


Your statement above is completely wrong. I assure you, any time there is fluid flow there is a pressure gradient – even if it’s only 1 GPM in a 12’ conduit. The pressure would be so small that you could assume it’s ZERO – But it’s NOT zero (that’s were you’re hung up). You can NOT have flow without some kind of pressure head forcing it to move. I think you're stuck or flip-flopping someplace, because someplace in these discussions you agreed that you have to have a pressure gradient when flow is involved – see below.

Originally Posted By: Gary Allan
Yes, fluid can not flow without potential/differential. Why you're hung up on this minor player here ..well, it's hard to figure.



Are we in the Twilight Zone?

I’m done at this point, as this will just go round and round and spin itself into oblivion, if it hasn’t already.

 

[Gary Allan]

Okay ..now we're really into the game playing.

Quote:
You can NOT have flow without some kind of pressure head forcing it to move.


You're really making me do this. Thanks. You're really stifling the discussion for worth ..but I'll play along.

Sure. Now have your sump at pump level ..and have it discharge into an infinite size conduit ..the Holland Tunnel ..but it discharges at mid point in the diameter. The sump is a reservoir at pump level.

What pressure can be read? Even micro readings will be balanced with the reduction of the sump level and the increase in the static atmosphere. Self balancing outside the pump. Run any pump into nothing.

Are we done playing?

 

[SuperBusa]

Originally Posted By: Gary Allan
Okay ..now we're really into the game playing.

Originally Posted By: Me
You can NOT have flow without some kind of pressure head forcing it to move.


It's a true statement ... can't weasel out of it, as physics don't "play games".

Originally Posted By: Gary Allan
You're really making me do this. Thanks. You're really stifling the discussion for worth ..but I'll play along.

Sure. Now have your sump at pump level ..and have it discharge into an infinite size conduit ..the Holland Tunnel ..but it discharges at mid point in the diameter. The sump is a reservoir at pump level.

What pressure can be read? Even micro readings will be balanced with the reduction of the sump level and the increase in the static atmosphere. Self balancing outside the pump. Run any pump into nothing.

Are we done playing?


Your example as stated above is not really a true flow scenario in a closed system ... it's a "reservoir" flow scenario as you said. Open conduit and reservoir flow scenarios don't quite have the same laws as closed system flow.

BUT, if you capped the ends of the Holland Tunnel and keep filling it up with fluid until the "reservoir tank" was full, and also had a small long (restrictive) tube coming out one of the end caps, then you would have flow through a closed system. Sure, you probably couldn't actually measure the flow in the tunnel section, but you certainly could in the small outlet tube after the tunnel filled up and started squirting fluid out. You would also see the pressure rise inside the tunnel after it was full and started forcing flow out the small outlet tube. The pressure would rise to whatever level was required to flow the pump's output through the small restrictive tube (plus any head pressure needed for reservoir fluid elevation of course). Now doesn't this sound a lot like a gigantic oil filter the size of the Holland Tunnel feeding an engine's oil circuit? Are we on the same page yet?

When you run a pump in to closed system with any significant resistance, like an engine's oiling system, then you will have to develop pressure that will be proportional to the amount of flow and the amount of resistance associate with the circuit. Bernoulli says so.

 

[SuperBusa]

Originally Posted By: Pete C.
Originally Posted By: LuciferCaitiff
YEESH!....
The dumb-guy's explanation I got (because I'm a dumb guy) was that a larger filter gives more surface area for oil to pass through, therefore it passes through at a lower pressure (not much lower I assume), and therefore gives the filter more chance to do its job.


You are correct in your assumption EXCEPT it is at a reduced velocity not pressure.


Actually, even as you make a filter's element larger and larger, you are still putting the same amount of flow through it as long as the PDP isn't in relief mode. Therefore, if you spread the same flow volume over a larger surface area, then both the flow velocity and the associated pressure drop across the element must go down.

Think of forcing say 5 a gpm flow through a little filter element the size of a thimble vs. one the size of a coffee can. Which one has high flow velocity across the element? Which one has the higher PSID?

Another good reason to use the largest oil filter you can find for you vehicle’s application.

 

[Gary Allan]

Quote:
Your example as stated above is not really a true flow scenario in a closed system ... it's a "reservoir" flow scenario as you said. Open conduit and reservoir flow scenarios don't quite have the same laws as closed system flow.


No? You don't say. So we can throw out all of the physics you just mentioned? No pump head ..the internal pressures merely evaporated with a few key strokes?

I see

Now let's run the same pump in a loop. Assuming it's not too long ..(make it REAL short) ..and the friction of the conduit is a hypothetical zero ..what's the line pressure in the conduit? Where did the pressure go

If it was long enough, and/or the friction was high enough, you would read a pressure right off the pump head ..ZERO somewhere around mid-span ..and a progressive suction/vacuum as you reached the pump.


Quote:
BUT, if you capped the ends of the Holland Tunnel and keep filling it up with fluid until the "reservoir tank" was full, and also had a small long (restrictive) tube coming out one of the end caps, then you would have flow through a closed system.


Ah ...NOW we can isolate the conduit from the pump. I see your sound reasoning here. I think I'll take your approach.

So, as the pump, that has its own internal pressure elevating properties ..now fills a cavity ..that will, due to the flow introduced ...produce a "back pressure" that is totally independent of the pump head ..and is dictated by the ultimate resistance that the conduit presents to the supply ..since we know that it's going to be a fixed volume passing through it ..and if we add an intermediate choke ..that it (the choke) will be altered in appearance by the ultimate terminal outlet size of the capped off end of the tunnel ..and if that terminal outlet is 1/20th of the size of the intermediate choke ..that the fluid will only make minor velocity changes at that choke ..and show next to nothing in pressure exerted in accelerating the flow from a crawl ..to just above a crawl. The stuff, as you lead me to believe with this genius view, may be screaming out the end of the conduit.

Thanks for reasoning that out for me. You've been a big help.

 

[SuperBusa]

Originally Posted By: Gary Allan
Now let's run the same pump in a loop. Assuming it's not too long ..(make it REAL short) ..and the friction of the conduit is a hypothetical zero ..what's the line pressure in the conduit?


It all depends on the flow rate and resistance of the loop. You said it wasn't too long, but you didn't say it wasn't very small in diameter or very resistive to flow. You said it had hypothetically zero friction, but frictional losses are separate from choked flow loss.

Originally Posted By: Gary Allan
Where did the pressure go

If it was long enough, and/or the friction was high enough, you would read a pressure right off the pump head ..ZERO somewhere around mid-span ..and a progressive suction/vacuum as you reached the pump.


Ya got that one right! But yeah know what, the oil pump on a typical car oiling system doesn't suck off the return line, so that example is deviating from the discussion ... we are jumping all over the place with different flow scenarios - possible diversion tactic? What do you know about open culvert flow, or what about back EMF as it pertains to permanent magnet DC motors?

Originally Posted By: Gary Allan
Thanks for reasoning that out for me. You've been a big help.

No problem ... I knew you'd get it sooner or later.

And don't let Bernoulli scare ya.

 

[Gary Allan]

Quote:
Ya got that one right! But yeah know what, the oil pump on a typical car oiling system doesn't suck off the return line, so that example is deviating from the discussion


..and I took us here? Where did I go wrong?

Quote:
we are jumping all over the place with different flow scenarios


What's this "we" [censored], pale face??

Quote:
possible diversion tactic?


That was my take on it. You came to that conclusion too? Better get that clown to stay on topic next time. I'll leave that to you to keep the "other guy" in line.

Quote:
What do you know about open culvert flow


It's been a while ..and I'd need a refresher ..but I've calculated flow loss over xx feet based on the material of the aqueduct and other factors. The problems were relatively simple.

Quote:
or what about back EMF as it pertains to permanent magnet DC motors?


Never paid much attention to the micro fractional stuff.



If you're doing some brain pan comparison for your ego's sake ..I'm not all that disciplined an individual. Most all that I've learned is self taught. You can smoke me on most topics that you've sat and read a book on. Most of my knowledge is from integration of observation. You can relabel it as you please if it makes you feel better

 

[Gary Allan]

I tried to make it easier for you to understand the physical events that take place within an oil filter. This proved to be an impossible task. You insisted on clinging to models that didn't depict the events in clarity.

An astrophysicist commented on relativity. He said that people focus too much on the alterations on the clock ..since they're mostly called to do that exercise in proving it. He said that they tend to be unable to view it from the aspect of the events that occur.

(no, I can't think in that realm either).

 

[SuperBusa]

Originally Posted By: Gary Allan
If you're doing some brain pan comparison for your ego's sake ..I'm not all that disciplined an individual. Most all that I've learned is self taught. You can smoke me on most topics that you've sat and read a book on. Most of my knowledge is from integration of observation. You can relabel it as you please if it makes you feel better

I’m not trying to “smoke you” with my inputs to these discussions. My background has nicely melted book knowledge to practical everyday experience, which I have lots of also. I have a 20+ year of testing background. When integrating the two together it pulls all the pieces together for a better understanding. For instance, everything we’ve discussed can be applied to Bernoulli’s flow equation – just like much of electrical flow can be applied to Ohm’s law. These equations and principles are tried and true.

Originally Posted By: Gary Allan
I tried to make it easier for you to understand the physical events that take place within an oil filter. This proved to be an impossible task. You insisted on clinging to models that didn't depict the events in clarity.


Actually, I fully understand the flow and physical events that take place within an oil filter. You may not think so, and the reason why is because we have different ways of looking and describing things. I’m sure if we were face-to-face over a beer we would agree more than not.

 

[Gary Allan]

Then ..in all that you've posted ..all of your objections ...your insertions of all the references ...

..was to state that you agree with me and only took us on the trip due to us being unable to communicate in a like manner?

You're right. I don't see that as being so. I found it a basic lack of abstract thinking (which is just about my only tool).

Yes, face to face I could manage to get through to you

 

[SuperBusa]

Originally Posted By: Gary Allan
Then ..in all that you've posted ..all of your our objections ...your our insertions of all the references ...

..was to state that you we agree with me each other and only took us on the trip due to us being unable to communicate in a like manner?


What's this "your" [censored]?

... see corrections to your quote above.

Originally Posted By: Gary Allan
Yes, face to face I could manage to get through to you we could manage to teach each other something.

More corrections above ... I'll bring by Fluids books.