Does the filter really alter performance?

[SuperBusa]

Originally Posted By: Corvette Owner
I did a google and it looks like only 2 psi pressure drop can be attributed to the oil filter. This is relatively insignificant when compared to the 40-60 psi of a running engine. I think this is the point he was making.


So what flow conditions was this 2 psi pressure drop across the filter associated with? If I had to guess, I'd say when the oil was hot and thin. Also, what filter was this for. I'm sure there must be some variance between filter resistance, but maybe it's not enough to be concerned about.

Seems like these discussions keep going round in circles to some degree because there are rarely qualifiers put on general statements made.

The filter's pressure drop is dependent on many factors that dynamically change in the oiling system - namely, the oil viscosity and the oil pump's flow rate (which changes with engine RPM). It's a very dynamic system. Obviously, the highest filter PSID will occur at the highest flow rate with the highest oil viscosity (ie, redline with oil at -20 deg F for example). Of course, the highest PSID any filter could achieve is equal to it's bypass valve setting.

I guess one way of looking at the split of filter vs. engine pressure drop would be by looking at the filter vs. engine PSID ratio. If a filter drops 2 psi while the engine oil pressure is say reading 50 psi, then the ratio PSID ratio is 2:50 (filter:engine).

So if the max relief pressure of the oil pump is set to say 90 psi, then one would expect the PSID across the filter just before the pump goes into relief mode to be (90/50) x 2 = 3.6 psi.

 

[Gary Allan]

Quote:
IMO, and based on fluid dynamics, there will always be some level of PSID across a filter is there is flow across the filter ... regardless if the filter has any back pressure on it or not. A PSID of 10 can be achieved by putting 10 psi on the inlet with 0 psi on the outlet, or by putting 210 psi on the inlet with 200 psi on the outlet ... or any similar combination.


No argument from me. Your scale of perception is wrong. From fractional inches of water column to 1-2 PSID (inverted as visc decays with warmup). It is the only evidence of the velocity change.

Quote:
The driving force that makes the oil flow is the 10 psi in these examples.


No, the driving force is 210lb to atmosphere. The 10 psid is the load, as expressed in increased pressure, created either accelerating or decelerating the fluid through either a rapids or a lower velocity void.

Quote:
In a case where the oil viscosity is constant, the PSID will go from 0 to some max right along with the developed pump pressure going from 0 to it's relief pressure.


No. This is not correct. The filter may be on a scale of .00001-2psid merely expressing the pressure addition created in the decel:accel event while not in a relief condition. When in relief, THEN the filter will appear as you assert. The engine, otoh, will be many times that magnitude ..like 0-40-60-80-100 whatever.

Quote:
When you say "Unless the pump is in relief (or leaking internally), there is no appreciable PSID across the filter.", there needs to be specific qualifiers associated with that statement.


I thought that I've given many ..but apparently not nearly enough

Quote:
There is always some level of pressure drop across the filter if there is flow through it.


Yes.

Quote:
That level depends on the volume and viscosity of the flow.


Yes.
Quote:
If the volume is high and viscosity high (redline with -20 deg F oil - ouch), then the PSID is max ...


Yes, but that is most assuredly a relief event. If the pump had a super strong intermediate shaft ..and titanium parts throughout and a 2500psi pressure limit you may actually see the spec'd readings, indexed for viscosity, that you appear to be seeking at any other time ..but don't exist at those times.

You can't get there from here. You'll never push high visc oil at high volume through an engine without a pump relief event.

Quote:
if the volume is low and viscosity low (hot oil at idle), then the PSID is small and negligible like Gary has indicated.


If the volume is reasonably high and the visc is low the PSID will still be very low. It will be in proportion to total pressure development across the circuit. If the engine is low, the filter will be even lower. Here's where you'll get to the "inches of W.C." PSID. As long as that pump is sending 100% of its sensible flow to the engine, that filter isn't even there for the vast galactic expanse of most instances.

Quote:
Not sure I follow ya here - I think it's word semantics and writing style getting in the way. IMO, any time there is flow through the filter/engine circuit there is a pressure drop happening ... both across the filter and across the engine's circuit. Think of the engine's complex oiling circuit as one fixed resistor, which it really is.


Here's where your view MUST be altered. You appear to view things as a pressure applied through a given resistance. This is opposed to a given flow at visc through a given resistance. One will have decreasing flow based on increased resistance at a fixed pressure. The pressure will be dissipated across the total resistance. For example, If I tap into a hose at midspan, I'll see half the pressure of the supply ..with an eventual zero as the water dumps out of the end. In a flow dictated circuit, I have no fixed pressure applied. The pressure is a product of the fixed volume pushed through the fixed resistance (assume stable viscosity to eliminate confusion = or water). My velocity will be identical from one end to the other (naturally) ..and my velocity will be identical through 1/2 the length of the conduit ..or one longer ..as long as I don't reach the relief level of the pump. Pressure is NOT a result of pressure drops accompanied with velocity drops across the span of the resistance ..but rather pressure ELEVATIONS that are backing up toward the supply.


Put a 10ohm resistor and a 100 ohm resistor in series and read across the 10ohm resistor. Apply as much current as you please. The 10ohm will ALWAYS be in a ratio of 10:1 with the 100ohm resistor. For a filter, I'll call it a 2ohm resistor in series with a 98ohm resistor. It will always be at that ratio of pressure (voltage) development no matter how much current you apply.

The reactive nature of visc makes this a harder example to articulate. Impedance is hard to express here (below)

Now when you're in relief, then you no longer have a series circuit as seen from the pump. You have a parallel circuit with the filter/engine on one branch ..and a variable resistor on the other. Now the supply IS pressure regulated. Now the 98ohm resistor does have a voltage/pressure drop across it that is factored the same way (E=Ixr) ..but the 2ohm isn't a static resistor now. It's seeing the product of the current through the 98ohm on one side (downstream) and the regulated supply pressure above it. It now "drops" the difference between the two.

Quote:
It took 20 psi to move that fluid volume (ie, GPM) through the tube.


No. 20 psi was developed moving a specific volume through the tube. THIS IS NOT SEMANTICS. IT'S A CRITICAL DISTINCTION. YOU MUST GRASP THIS DIFFERENCE TO UNDERSTAND. I think I covered it back a bit in like detail.

Q: How fast does 5gpm move through a 1/2" pipe?
Q: How fast does 5gpm move though a 2" pipe?
A: 5gpm.

Note that there is absolutely NO reference to pressure. The pressure is a product of the dedicated flow. The flow is NOT a product of pressure over a given restriction.

That's how positive displacement pumps work when not in relief. They just pump volume ..the pressure is what is developed at that volume (at that visc).

 

[SuperBusa]

Originally Posted By: Gary Allan
Quote:
It took 20 psi to move that fluid volume (ie, GPM) through the tube.


No. 20 psi was developed moving a specific volume through the tube. THIS IS NOT SEMANTICS. IT'S A CRITICAL DISTINCTION. YOU MUST GRASP THIS DIFFERENCE TO UNDERSTAND. I think I covered it back a bit in like detail.

I don't have the time right now to address every back and forth we have in these discussions, plus it's late, so I'll just respond to this one.

I think it is really semantics, as you've basically just said the same thing I did. Maybe we just don't write and read the same, but more times then not we say the same things in different ways. When I said "It took 20 psi to move that fluid volume (ie, GPM) through the tube." that means it takes 20 psi to move a certain volume of fluid through a certain fixed resistance. Isn't that the same as saying "20 psi was developed moving a specific volume through the tube." ? To me it is.

In reality, a moving fluid does not "develop" a pressure. In contrast, a pressure must be present to move the fluid ... just like there must be a voltage to make current move through an electrical resistor. It really is semantics.


Originally Posted By: Gary Allan

Q: How fast does 5gpm move through a 1/2" pipe?
Q: How fast does 5gpm move though a 2" pipe?
A: 5gpm.

Note that there is absolutely NO reference to pressure. The pressure is a product of the dedicated flow. The flow is NOT a product of pressure over a given restriction.


Again, Gary I think it's a way of thinking and semantics on these issues. You and everyone else with any kind of engineering logic knows that it takes pressure to move a fluid in something. Pressure is NOT developed as a result of flow ... it's the other way around. Flow is a result of pressure, and how much volume of flow that can be moved at a given pressure is dependant on the resistance of the circuit you are trying to flow through. It's a direct analogy in the electrical circuit ... you can't have current (flow) without pressure (voltage), and the amount of flow you get is dependant on the resistance of the circuit.

If you applied the electrical analogy to your questions above, you'd see that it takes more pressure to flow 5 gpm through a 1/2" than a 2" pipe. Just like it takes more voltage to push the same amount of current through a resistor that is 4 times more resistive. But in the fluid flow scenario, it's a fact that the velocity will also have to increase if you are pushing 5 gpm through a smaller tube, along with the pressure increase required.

Originally Posted By: Gary Allan
That's how positive displacement pumps work when not in relief. They just pump volume ..the pressure is what is developed at that volume (at that visc).


The way I see positive displacement pumps (PDP, new acronym for ya) is that the pressure they put out on their output side is directly dictated by how much resistance is on the output side - and of course the viscosity of the fluid it's pumping. It sounds like that what you're saying also. Let me expand in detail.

Ideally, a PDP would try to put out whatever pressure is needed to move the output volume. In an extreme example, lets say the PDP puts out 20 GPM (it's a big one) at some constant speed, and has NO relief valve.

Let's say you hook up a 1 inch tube that's only 5 ft long to it's output. The fluid is at xyz viscosity, and it take only 3 psi to push the 20 GPM output through the tube. Now lets say you hook up a 1/8" tube that is 300 ft long to the output. The fluid is still at xyz viscosity, and this time it takes 275 psi to push that same 20 GPM through the smaller tube.

So, as you can see, the amount of PDP pressure developed is directly dependant on the amount of resistance you put on it's output side. This is exactly why there is a built in relief valve, otherwise the thing could go so sky high that something would eventually fail if there was too much resistance on the output side of the PDP. Sometimes relief valves can stick or fail, and the result is very high engine's oil pressure because the pump is trying to put all of its output volume through the system. Then there are guys who shim the pump's relief valve (to make it open at higher pressure) for that very reason ... to get more oil volume and higher oil pressure.

 

[SuperBusa]

Originally Posted By: Gary Allan

Quote:
Not sure I follow ya here - I think it's word semantics and writing style getting in the way. IMO, any time there is flow through the filter/engine circuit there is a pressure drop happening ... both across the filter and across the engine's circuit. Think of the engine's complex oiling circuit as one fixed resistor, which it really is.


Here's where your view MUST be altered. You appear to view things as a pressure applied through a given resistance. This is opposed to a given flow at visc through a given resistance.


OK ... I had to address this one too. We seem to have a different way of looking at this stuff. But please realize that there will be NO flow without pressure. Flow does NOT create pressure, but pressure creates flow. So yes, in essence it really is the way I view it ... that is "pressure applied through a given resistance". That's exactly what fluid dynamics is.

You see it as "a given flow at visc through a given resistance" ... but think about it. In order to make that given flow at a certain viscosity go throug a given resistance then you will need pressure to do so.

Pressure is the driving force ... period. Pressure is created inside the pump by the mechanical input power to pump. Pressure is not created as a result of the flow through the resistance - and pressure is not a "by product" of the flow. Pressure is the only thing that causes the flow to go through the resistive circuit that’s connected to the pump’s output.

 

[Gary Allan]

I'm well versed on differentials and flows. All you've stated is correct in the limitations of those perceptions.

What you're NOT gleaning is the difference with a static applied pressure across a conduit and a given flow transmitted through a conduit.

You're anchoring the WRONG PARAMETERS every time you state it.

FLOW dictates everything in this situation.

You can't exchange the parameters when you're reasoning this.


Your examples (as you express them): I have 100 psi/volts applied to a 100ohm resistor = I get 1 amp.

YOU MUST SAY: I'm pushing 1 amp through a 100ohm resistive circuit and I develop 100 volts from supply to ground.

It's a current regulated circuit. The resistance is variable (by either flow rate or visc). The pressure is a result those two elements. NOT the other way around.


Yes, a pressure differential is required for flow to occur. The difference between what I see you saying and what is occurring is that the flow in our scenario has no choice but to occur. The differential is developed in just the right amount to move that mass through that resistance at that flow rate.

NOW when you switch to the relief event ..THEN you've got an applied pressure through a given resistance ..and a resulting flow through the engine.

This is why that distinction is ABSOLUTELY CRITICAL. The way you're stating it only occurs in the relief event. An applied pressure through a given resistance ..resulting in a given flow rate through the engine. The difference (of total pump output vs flow to the engine) is going to the relief port.

 

[Zaedock]

Holy poop. I need another coffee.

 

[RD400]

So, in summary, the answer is no?

 

[Gary Allan]

As far as the OP's question (what was it

)???


Not in any instance I can think of. Now punch a few holes in the media ..and not change the thing for 60k ...then I'd say that it might alter a few things that may evidence themselves in terms of performance degradation.

 

[SuperBusa]

Originally Posted By: Gary Allan
I'm well versed on differentials and flows. All you've stated is correct in the limitations of those perceptions.

What you're NOT gleaning is the difference with a static applied pressure across a conduit and a given flow transmitted through a conduit.

You're anchoring the WRONG PARAMETERS every time you state it.

FLOW dictates everything in this situation.

You can't exchange the parameters when you're reasoning this.

Your examples (as you express them): I have 100 psi/volts applied to a 100ohm resistor = I get 1 amp.

YOU MUST SAY: I'm pushing 1 amp through a 100ohm resistive circuit and I develop 100 volts from supply to ground.

It's a current regulated circuit. The resistance is variable (by either flow rate or visc). The pressure is a result those two elements. NOT the other way around.


Gary – obviously there are two ways to look at this stuff (your way and the right way ... j/k

), but in a classical engineering point of view (which I use), the driving force that causes a fluid to flow is always pressure. When you say the statement ...

“YOU MUST SAY: I'm pushing 1 amp through a 100ohm resistive circuit and I develop 100 volts from supply to ground.”

... it doesn’t really make sense. This is because you say you are “pushing” ... well, what’s the source of the “pushing”? (hint – pressure). Flow just doesn’t happen without the driving force of pressure. You can not “develop” pressure by flow - at least not in the sense we are talking about in engine oil systems. You can’t make a fluid flow without applying a pressure to it. It’s just impossible. Flow and pressure are obviously tied together, but it’s always pressure that makes flow happen – not the other way around.

Your semantic are basically backwards, yet you think mine are ... it’s kind of ironic. This is why we always seem to go round and round in these discussions ... because you are visualizing these physics in your own physical world instead of the real physical world. In the end, we basically say the same thing, but the way it’s communicated is "bass ackwards" at times. I guess everyone has their own “style” of describing something, but from an engineer’s view point there is only one true way of how flow happens.

Originally Posted By: Gary Allan
Yes, a pressure differential is required for flow to occur. The difference between what I see you saying and what is occurring is that the flow in our scenario has no choice but to occur. The differential is developed in just the right amount to move that mass through that resistance at that flow rate.


Of course a fluid has no choice than to flow when a pressure is forcing it to move. That’s true for all fluid flow scenarios. You have 3 main parameters: Pressure, resistance and flow. When you apply the pressure it makes the fluid flow through the resistance, and the flow is determined by how much pressure vs. resistance you have. If pressure isn’t making the fluid move, then what is?

When you apply a pressure against the fluid to make it move through a resistance, you achieve flow. That’s what’s going on. It’s not “you make flow happen (some how magically) which then produces pressure” ... how can that be when it’s pressure the makes the flow? See the difference? The ONLY case where you could produce a pressure from a fluid flowing is in stagnation pressure scenarios – ie, a pitot tube or water falling over a dam and deaccelerating. But obviously, the oil flow in an engine’s oiling system is not being driven by gravity or velocity (ie, airplane ramming in to air as it flies – see links below).

http://en.wikipedia.org/wiki/Stagnation_pressure
http://en.wikipedia.org/wiki/Pitot_tube

Here is a short article that has it right ... they realize that it’s the pump’s output pressure that moves the oil ... what else could?

http://www.le-international.com/uploads/documents/113_Oil Pressure Changes.pdf

Originally Posted By: Gary Allan
NOW when you switch to the relief event ..THEN you've got an applied pressure through a given resistance ..and a resulting flow through the engine.

This is why that distinction is ABSOLUTELY CRITICAL. The way you're stating it only occurs in the relief event. An applied pressure through a given resistance ..resulting in a given flow rate through the engine. The difference (of total pump output vs flow to the engine) is going to the relief port.


When the oil pump is in relief mode there is really no change in the physics that actually causes the oil to flow through the engine’s oiling system ... it's still pressure from the pump.

The only things that have changed when the pump is in relief are:
1) The oil pump has reached its maximum allowable operating output pressure because the relief valve is operating – this maximum pump pressure is on the pump’s output side and is supplying the max possible pressure to the filter/engine oiling circuit.
2) The flow volume going through the engine’s oiling circuit has decreased because some of the pump’s output volume has been diverted back to the sump.

Even though some of the flow volume has been diverted from the oil pump and doesn’t go through the engine, there is still pressure feeding the engine’s oiling circuit, which in turn still forces the reduced volume of oil to flow through the system – pressure is always needed to move the oil, regardless if the pump is in relief or not. The only difference is that the flow volume has reduced to match the max pressure output level of the pump.

In ALL cases within the oiling system (your quote follows) ...“you've got an applied pressure through a given resistance ..and a resulting flow through the engine”. Yes, this is true in ALL cases, even when the pump is in relief mode, based on the reasons I gave above.

Anyway, that’s my viewpoint and I’m stickin’ to it. Not to say your viewpoint isn’t right, but it’s very confusing and misleading at times, and not always in line with classical fluid dynamics. I’d suggest doing some research, as almost all fluid dynamics formulas pertaining to fluid flow contain the pressure parameter for a good reason.

I say tomato ... you say tomauto.

 

[SuperBusa]

Originally Posted By: HARTZSKY
Can you guys see/hear a difference from 1 oil filter to the next? Can the right/wrong filter cause better/worse engine performance?


To give you one perspective, I visit a busy chat board for Nissan Altimas, and there have supposedly been cases where using one filter over another has caused (or quieted) cold startup noises on the Nissan engines. They use oil pressure for the internal cam-chain mechanisms and also for the mechanical valve timing mechanisms.

I'd probably say the reason was because some filters may not have a very effective anti-drain back valve (ADBV), and if the car sits for overnight or longer enough oil has drained out of the system and it takes a second or two to get enough pressure after startup to activate those mechanisms.

IMO, having a well sealed ADBV could be a very important performance aspect of an oil filter, depending on the engine application.

 

[Gary Allan]

OMG ..has this been some peezing contest for you all this time?

Okay ..pal

Bravo!

I'll try this one more time

With fluid flow in a positive displacement situation (ignoring any losses and whatnot) ..you're always solving for P (pressure). At any one moment in time, that's the ONLY variable.

I can't state it any more simply than that. How hard is that for you to concede

You really went to a lot of typing just to avoid that one small concession.


All this time I've been trying to give you a way to view it where it may make sense to you ..and all this while you've been trying to come up with ways to avoid that.

Amazing. But you've remained civil ..to that I give you a tip of the hat.

..and no matter how much you wish it to be true, you filter, in many more instances that not ..will be a marginally minor player in the fluid circuit.

 

[SuperBusa]

Originally Posted By: Gary Allan
OMG ..has this been some peezing contest for you all this time?

... I don't think you even read what I type anyway.

If it's a pizzing contest for me (as you claim), then you're also a participant and a fellow "pizzer" as you always try to "correct" my thinking. Sorry, but there is nothing to correct. I call it a friendly debate on technical issues that are not agreed upon.

Originally Posted By: Gary Allan
Okay ..pal

Bravo!

I'll try this one more time

With fluid flow in a positive displacement situation (ignoring any losses and whatnot) ..you're always solving for P (pressure). At any one moment in time, that's the ONLY variable.

I can't state it any more simply than that. How hard is that for you to concede

You really went to a lot of typing just to avoid that one small concession.


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.

Originally Posted By: Gary Allan
..and no matter how much you wish it to be true, you filter, in many more instances that not ..will be a marginally minor player in the fluid circuit.


Yes, we've hashed that one and I agree the filter is only a small part of the flow resistance - except maybe in some cold start situations. But the focus has boiled down to simple fluid dynamics and the view of how pressure, flow and resistance tie together. I know it's not rocket science, so I can't see how this different viewpoint is even possible.

 

[Gary Allan]

Quote:
... it doesn’t really make sense. This is because you say you are “pushing” ... well, what’s the source of the “pushing”? (hint – pressure). Flow just doesn’t happen without the driving force of pressure. You can not “develop” pressure by flow - at least not in the sense we are talking about in engine oil systems. You can’t make a fluid flow without applying a pressure to it. It’s just impossible. Flow and pressure are obviously tied together, but it’s always pressure that makes flow happen – not the other way around.


Granted .. So?

Now tell me what pressure you need when pushing xx fluid through xx conduit at yyy rate?

Don't know? Well ..I'd say that I'll turn the engine on ..and a given flow will pass through the conduit ..and produce a pressure reading. Now I know how much pressure is exerted to push that flow through that conduit. The pressure will vary with viscosity. The flow and the conduit will not.

Solved for P

Quote:
Of course a fluid has no choice than to flow when a pressure is forcing it to move. That’s true for all fluid flow scenarios. You have 3 main parameters: Pressure, resistance and flow. When you apply the pressure it makes the fluid flow through the resistance, and the flow is determined by how much pressure vs. resistance you have. If pressure isn’t making the fluid move, then what is?

When you apply a pressure against the fluid to make it move through a resistance, you achieve flow. That’s what’s going on. It’s not “you make flow happen (some how magically) which then produces pressure” ... how can that be when it’s pressure the makes the flow? See the difference? The ONLY case where you could produce a pressure from a fluid flowing is in stagnation pressure scenarios – ie, a pitot tube or water falling over a dam and deaccelerating. But obviously, the oil flow in an engine’s oiling system is not being driven by gravity or velocity (ie, airplane ramming in to air as it flies – see links below).

http://en.wikipedia.org/wiki/Stagnation_pressure
http://en.wikipedia.org/wiki/Pitot_tube

Here is a short article that has it right ... they realize that it’s the pump’s output pressure that moves the oil ... what else could?


Granted and conceded to ...and how is this germane in the discussion at hand?

We're dealing in a flow dictated environment (non-relief). If you can't see that pressure is dependent on the mandated flow/visc/resist aspects of the equation ..then we're at an impasse.

Flow is immutable in this discussion.




I have to figure that you're fighting tooth and nail to avoid viewing it from that angle. If you refuse to do so ..just to determine if you agree or disagree with me ..we can go nowhere.


I can have internal pump head that pumps into a 12' conduit with a 12' outlet and develop NO PRESSURE IN THE CONDUIT.

KEEP IN MIND THAT WE'RE VIEWING THE EFFECTS OF FLOW, AS EVIDENCED IN TERMS OF PRESSURE AS SEEN BY THE FILTER.

The internal pump head as nothing to do with that discussion. The pump, without a relief mechanism has NO LIMIT to its pressure potential and therefore no limit to its flow potential.

In short ..all of your quotes aren't moving us to being able to view the filter, as it is effected, in the way necessary to demonstrate the physical events that occur.

Is that better?

 

[HARTZSKY]

Hey, what about my original question? LOL

 

[Gary Allan]

Originally Posted By: HARTZSKY
Hey, what about my original question? LOL


Quote:
Can you guys see/hear a difference from 1 oil filter to the next? Can the right/wrong filter cause better/worse engine performance?


Not in any way I can figure. Even detecting filter performance differences (start up rattle)..beyond whether the ADBV is working well, is something I doubt too many can manage without a whole lot of work.

Now if your oil pump has issues, then you may be able to hear lingering HLA noise with a (cue dramatic music

) a "more restrictive" filter over one that is not so ..but there we're viewing an engine condition. Millions of units won't experience this.

 

[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.

You have a pump it has a reservoir at level with the impeller ..so it has zero suction head to pull ..and, at the rate that it's running, produces 1 gpm of flow. It has a 6" intake ..and a 6" outlet ..and discharges in to a 100' high pipe with a flat bottom that's 10,000' long and no other restrictions until it dumps into a storm drain. The pump is level with the pipe.

What will be the static pressure in the pipe after 10,000 years of operation?

ZERO.

You can have INFINITE internal pump pressure (well, nearly) as far as elevations inut ..and with no appreciable flow ..you will develop no "back pressure" into a given conduit.

In my above example, the volume required to pressurize the 100' open ended pipe would have to be so high that it would effectively turn it into a fire hose 10,000' long ..where the length of the conduit, fully enveloped, became part of the equation.

Are we getting somewhere?

 

[Al]

Originally Posted By: Cyprs
my father swears his Nissan Sentra is running much quieter, smoother and more responsive with a filter nearly 3X bigger filter than the suggested OEM thimble sized filter

Not sure where you are getting a filter 3X bigger. The upgraded size difference is maybe40% bigger at best.

 

[LuciferCaitiff]

YEESH! There's a lot of complicated scientific information and big words that don't even really answer the question.

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. I commute on my motorcycle, so my car often goes 5 days without starting up, so I need oil in that filter. K&N seems to have a great ADBV, Mobil-1 is just as good from what I remember.

Now there IS also the question of larger filter giving better filtration. The arguments I've read here mostly relate to oil pressure, which I'm pretty confident my car will be fine in that department. I recently managed to fit a Porche 944 (K&N HP-4001) filter on my car, it's the same fit, just a larger filter. It's a few inches longer than the HP-1004, and even larger than the nippon filter that the Honda dealer puts on their cars.

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.

This is the first oil change I've used the larger filter on, so I'll have to wait. I'm curious on the condition of my oil, and I'll probably cut my filter open to take a gander when it's time for a change.

what is the rocket scientist's dumb guy analysis on this idea? I'm really curious, and I don't want to start a new thread when it fits in this thread just as well.

 

[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.

 

[LuciferCaitiff]

aah ok, thank you for the clarification.

edit: I just realized how many times I used the word 'therefore'...I'm an idiot, heh