Compare resistances to flow of synthetic filters..

[OVERKILL]

To add to the above, how common a bypass event is in an application would directly relate to oil viscosity used, oil volume in the system and the headroom above the pump. Think of the act of starting. If you have an engine like a Modular with a stock pump that is relatively high volume/high pressure and it has a lot of things upstream of the pump that can bleed down, during a start-up event, the lack of pressure upstream of the media may allow for a brief moment of filter bypass until the engine becomes fully engulfed and the differential is reduced. During this time, if Ford's diagram is correct (and what I am describing here appears to be what they are illustrating) there is the potential for what has settled in the bottom of the can to be washed up and through the bypass into the engine. I don't think it is a concern for an engine that is already running and may, under WOT or something, experience a bypass event, as anything in the bottom of the can would probably be stirred up by the flow of the oil in the filter and be stuck to the media at that point. But when the engine has sat and things settle, that's where the particulate that was pressed against the media due to flow settles out and ends up on the bottom of the can. This is the stuff I believe Ford is talking about.

 

[TrevorS]

Another decision to worry about!

 

[dickwells]

On the modular engine the base bypass is critical for the sideways mounted filter. When you have gon nuts trying to solve starved cam on one side only to find a hunk of crud blocking that little oriface you will use motorcraft from then on.

 

[CarbonSteel]

Originally Posted By: dickwells

On the modular engine the base bypass is critical for the sideways mounted filter. When you have gon nuts trying to solve starved cam on one side only to find a hunk of crud blocking that little oriface you will use motorcraft from then on.

How does using a MC filter exclusively prevent this from happening? Are you suggesting the base end bypass is the only way to prevent it? What are the odds of this happening in a properly maintained engine? Just curious...

 

[ZeeOSix]

Originally Posted By: OVERKILL

Think of the act of starting. If you have an engine like a Modular with a stock pump that is relatively high volume/high pressure and it has a lot of things upstream of the pump that can bleed down, during a start-up event, the lack of pressure upstream of the media may allow for a brief moment of filter bypass until the engine becomes fully engulfed and the differential is reduced.

The delta-p across the filter media is only dependent on the flow volume going through it and the viscosity of the oil - doesn't matter what the pressure is on the outlet side of the filter. Doesn't matter if the oil galleries are completely full or completely empty of oil. And also, the oil volume hitting the filter is the same regardless if the galleries are full or empty because it's a positive displacement oil pump.

 

[ARCOgraphite]

Originally Posted By: ZeeOSix

Originally Posted By: ARCOgraphite

I might be more concerned about bypassing at high rpm, varying loads with low viscosity sump at 230C.

Very hard to get a filter to bypass with hot oil ... even at engine redline. Better check you "230C" ... that's 446 deg F. Not too many oils will take that and would be super thin. The hotter/thinner the oil, the harder it will be to make the filter go into bypass. High engine RPM with cold thick oil will put the filter into bypass much easier.

Sorry, Meant 230F.

 

[dnewton3]

As always, I do predicate my concepts on equipment and components operating in the designed manner and not in need of significant service. If we had to look at this from a DFMEA perspective (and I susepct that the major filter makers and OEMs have done so), then we need to acknowledge a few things here. This is about two concepts; frequency and severity. How often does the bypass event happen? Rarely, and even when it does, it's only for a very short period of time, and ONLY enough to relieve that dP, and once balanced the valve closes down again. The ADBV isn't like a poppet valve that delays opening until overwhelmed, and would only close upon full relief. These are spring-seat devices that can eek the smallest dP and flow, and rise in a crescendo only when the situation calls for. Secondly, how severe is the loading and normal wear, relative to a momentary burp of bypass? If the filter does a decent job in "normal" operation, there should be very little at any one given time in circulation. Add in a clean running engine, and the particulate load is just plain low. So, from the DFMEA viewpoint, we consider four operational possiblities: 1) low freq and low loading 2) high freq and low loading 3) low freq and high loading 4) high freq and high loading The only one that is really a big risk is #4; happens often in a dirty running soot monster and a poor air filter. Even the "moderate" concerns (#2 & #3) are not a big deal because one cancels the other. Happens often but little particulate? No big deal. Doesn't happen often, but has some heavying loading? The low fequency negates the heaving loading because the near-constant filtering cleanses the system. And the most desireable is actaully what we typically experience in the real world. Low event frequency and low loading. Rarely does a bypass open and when it does, it's reasonably clean oil passing by. If the BITOG fears were actaully realized often, then I'd think filters would be a lot more expensive, a great deal bigger, and changed OFTEN. And yet what do we see in the real world today? OCIs and FCIs are getting longer and longer, and yet many filter applications are trending smaller.

 

[OVERKILL]

Originally Posted By: ZeeOSix

Originally Posted By: OVERKILL

Think of the act of starting. If you have an engine like a Modular with a stock pump that is relatively high volume/high pressure and it has a lot of things upstream of the pump that can bleed down, during a start-up event, the lack of pressure upstream of the media may allow for a brief moment of filter bypass until the engine becomes fully engulfed and the differential is reduced.

The delta-p across the filter media is only dependent on the flow volume going through it and the viscosity of the oil - doesn't matter what the pressure is on the outlet side of the filter. Doesn't matter if the oil galleries are completely full or completely empty of oil. And also, the oil volume hitting the filter is the same regardless if the galleries are full or empty because it's a positive displacement oil pump.

Picture a filter partially full of oil that suddenly experiences a massive volume of cold oil being forced against the media and the bypass with nothing upstream of it to provide any resistance (the engine is not yet fully engulfed). The operation of the bypass relies on a differential occurring in a fully pressurized system. That is, the pressure on both sides of the media and both sides of the bypass are close to equal as long as the media can flow enough oil. When the media CANNOT flow enough oil, pressure on the OUTLET side is REDUCED enough that the valve opens. If there is NO RESISTANCE upstream of the valve, it is going to open. So that initial surge of volume that sees no resistance upstream of the filter on a cold start, if it creates 15psi of pressure inside the filter (which I'm sure is quite easy for you to imagine with cold oil) then the bypass is going to open because there is NOT 15psi of pressure on the OTHER side of that valve provided by the system UPSTREAM of the filter. It would be a momentary event of course.

 

[harry j]

Try this: Take a synthetic oil filter and a run of the mill paper one. Fill each with oil and see what one fills fastest.

 

[Jim Allen]

People that run an oil heavier than spec'ed have the most to worry about in terms of bypass frequency. Maybe people in cold climates too. The rest of us... it's really a non issue in the long run, regardless of the position of the bypass. I guess I can only speak for myself, but my autopsied filters... even the recently dissected 15K P1 you can find here, do not have as much crud in the can. Many of the others shown here do not either. I think the example shown may be an exhibit for something close to a worst case, or at least a bad case. If that is "normal" and 90 % of the oil filters used do not have a base end bypass, again that points to it being a non-issue for the most part. We are really debating in-theory minutiae here. It would be interesting if all the 4.6L UOAs that Dave studied had accurate info on what oil filters were used and he could compare the wear on the engines that used a base end bypass vs those did not.

 

[ZeeOSix]

Originally Posted By: OVERKILL

Originally Posted By: ZeeOSix

Originally Posted By: OVERKILL

Think of the act of starting. If you have an engine like a Modular with a stock pump that is relatively high volume/high pressure and it has a lot of things upstream of the pump that can bleed down, during a start-up event, the lack of pressure upstream of the media may allow for a brief moment of filter bypass until the engine becomes fully engulfed and the differential is reduced.

The delta-p across the filter media is only dependent on the flow volume going through it and the viscosity of the oil - doesn't matter what the pressure is on the outlet side of the filter. Doesn't matter if the oil galleries are completely full or completely empty of oil. And also, the oil volume hitting the filter is the same regardless if the galleries are full or empty because it's a positive displacement oil pump.

Picture a filter partially full of oil that suddenly experiences a massive volume of cold oil being forced against the media and the bypass with nothing upstream of it to provide any resistance (the engine is not yet fully engulfed).

The filter is experiencing the same oil volume flow it would always see (from the positive displacement oil pump), regardless if it is (and the oil galleries) bone dry, completely full or partially full. How is this filter seeing more some "massive" oil flow event just because it's not full of oil? The positive displacement oil pump is going to ensure the same volume goes through the system as long as the pump doesn't hit pressure relief, and in a start-up and engine idle condition the oil pump should easily remain below pressure relief point.

Originally Posted By: OVERKILL

The operation of the bypass relies on a differential occurring in a fully pressurized system. That is, the pressure on both sides of the media and both sides of the bypass are close to equal as long as the media can flow enough oil.

The filter's bypass valve only operates due to the delta-p across the media. The system doesn't have to be "fully pressurized" for that to occur. If you mounted an oil filter on a bench and had the outlet just puke into a bucket on the floor (like a garden hose), and if you flowed X GPM of oil at viscosity Y through it, you would still see the same delta-p across the media. The delta-p across the media is only dependent on the oil flow volume, oil viscosity and media flow resistance. It doesn't care what the inlet or outlet pressure is ... just the difference between inlet and outlet.

Originally Posted By: OVERKILL

When the media CANNOT flow enough oil, pressure on the OUTLET side is REDUCED enough that the valve opens.

Not sure what you mean by the pressure is reduced on the outlet side to make the bypass valve open (?). What happens is the pressure increases on the inlet side until the delta-p between inlet and the outlet is at or above the bypass valve setting - this is the only thing that opens the bypass valve. The pressure on the outlet side of the filter will always be lower than the inlet side, no matter what's going on in the oiling system - as long as there is some oil flowing.

Originally Posted By: OVERKILL

If there is NO RESISTANCE upstream of the valve, it is going to open.

Not sure of your terminology use. To me when visualizing the flow path of the oil (or a stream of water), "Upstream" means "before" the valve (filter inlet) and "downstream" means "after" the valve (filter outlet). If you mean no pressure after (downstream) the filter/valve, then what you said is not true. If there was zero pressure downstream and 15 psi upstream, then the bypass would start to open if set to 15 psi. It's a 15 psi delta-p ... that's all that matters to the bypass valve. More examples of a 15 psi delta-p would be as follow, and in all situations the bypass valve would start to open: a) 15 psi inlet, 0 psi outlet (atm pressure) b) 16 psi inlet, 1 psi outlet c) 40 psi inlet, 25 psi outlet d) 90 psi inlet, and 75 psi outlet e) 200 psi inlet, 185 psi outlet

Originally Posted By: OVERKILL

So that initial surge of volume that sees no resistance upstream of the filter on a cold start, if it creates 15psi of pressure inside the filter (which I'm sure is quite easy for you to imagine with cold oil) then the bypass is going to open because there is NOT 15psi of pressure on the OTHER side of that valve provided by the system UPSTREAM of the filter. It would be a momentary event of course.

Well of course if there is enough delta-p across the filter (15 psi in your example), it will open the bypass valve - regardless of how the delta-p was created (key). But got to realize that you do not need pressure on the outlet side of the filter to make anything special happen with the bypass valve. All it cares about it the delta-p across it, regardless how it happens. And yes, if there is a "surge" of cold viscous oil at start-up, then the bypass valve is probably going to open momentarily - regardless if the engine is "enveloped" or not. Even if the engine was idling with hot oil at 200 deg F and you instantly smashed the throttle to the floor had hit red line in 1/2 second, that nearly instant surge of oil may cause a short momentary pressure spike that could pop the bypass open for a second or two. But if you slowly increased engine RPM from idle to red line with hot oil the bypass valve will probably not open at all.

 

[OVERKILL]

Originally Posted By: ZeeOSix

Originally Posted By: OVERKILL

So that initial surge of volume that sees no resistance upstream of the filter on a cold start, if it creates 15psi of pressure inside the filter (which I'm sure is quite easy for you to imagine with cold oil) then the bypass is going to open because there is NOT 15psi of pressure on the OTHER side of that valve provided by the system UPSTREAM of the filter. It would be a momentary event of course.

Well of course if there is enough pressure delta-p across the filter (15 psi in your example), it will open the bypass valve - regardless of how the delta-p was created (key). But got to realize that you do not need pressure on the outlet side of the filter to make anything special happen with the bypass valve. All it cares about it the delta-p across it, regardless how it happens.

I think here is our disconnect (I deleted the rest of the post because I think our terminology is just getting messed up here). The differential (delta-p) observed over the bypass valve is what I'm referencing here when I speak as to pressure (or the lack thereof) on the outlet side relative to the inlet side. Cold thick oil that can't go through the media at the volume it is delivered by the positive displacement pump (I think we are in agreement here) will result in a differential occurring. My point was that in a non-engulfed system (which you reference below with the surge comment, which was exactly what I was getting at) with cold oil, that differential is created between what is essentially the pressure in the can (15psi for example) and absolutely nothing, because there's no oil pressure established on the other side of the media creating our delta-p and causing our bypass event. Yes the pressure doesn't have to be 0, it could be ANYTHING as long as we have a differential, but in a non-engulfed engine, it will be zero or close to it. We on the same page now?

Quote:

And yes, if there is "surge" oil cold viscous oil at start-up the bypass valve is probably going to open momentarily - regardless if the engine in "enveloped" or not. Even if the engine was idling with hot oil and you instantly smashed the throttle to the floor had hit red line in 1/2 second, that near instant surge of oil may cause a short momentary pressure spike that could pop the bypass for a second or two. But if you slowly increased engine RPM from idle to red line with hot oil the bypass valve will probably not open at all.

Yes, it MIGHT with hot oil, but it may, depending on engine design and oil pump volume be pretty much guaranteed with cold oil on a cold start. Hence my reference to the high volume/high pressure factory pump in the Modular earlier. And here's where I was going earlier with my comments RE: Ford's design. With hot oil in a running engine, it doesn't matter. Particulate is already pressed against the media, so a bypass event is insignificant. HOWEVER, with an engine that has sat overnight and the sediment has settled to the bottom of the can (see the Ford PDF for their graphic of this) that initial surge/bypass event can, if the bypass is dome-end and the filter is mounted in the manner in which Ford depicts, send that particulate into the engine. On a base-end bypass with the same filter orientation, that isn't going to happen.

 

[Jim Allen]

Originally Posted By: OVERKILL

And here's where I was going earlier with my comments RE: Ford's design. With hot oil in a running engine, it doesn't matter. Particulate is already pressed against the media, so a bypass event is insignificant. HOWEVER, with an engine that has sat overnight and the sediment has settled to the bottom of the can (see the Ford PDF for their graphic of this) that initial surge/bypass event can, if the bypass is dome-end and the filter is mounted in the manner in which Ford depicts, send that particulate into the engine. On a base-end bypass with the same filter orientation, that isn't going to happen.

On my 5.4 the dome and the base are at nearly the same level (filter nearly horizontal). If we are going to play it out in our heads without really knowing exactly what happens, to me that means the contamination has nearly an equal chance of going thru either bypass location. We should keep in mind that illustration from Ford has to be looked at as a bit of a sales pitch. When you are trying to sell something, you accentuate your unique features and present them as, "This is better and you gotta have it." I believe there is sound engineering principle behind it and I don't argue against that. I only argue as to the weight we give it as a "vital feature." Two of the three engineers I spoke with had no horses in this game so I think their opinions were largely based on engineering rationale rather than sales. The third... it's possible there was some sales bias in it but basically his opinion was the same as the unbiased engineers so....

 

[OVERKILL]

Originally Posted By: Jim Allen

Originally Posted By: OVERKILL

And here's where I was going earlier with my comments RE: Ford's design. With hot oil in a running engine, it doesn't matter. Particulate is already pressed against the media, so a bypass event is insignificant. HOWEVER, with an engine that has sat overnight and the sediment has settled to the bottom of the can (see the Ford PDF for their graphic of this) that initial surge/bypass event can, if the bypass is dome-end and the filter is mounted in the manner in which Ford depicts, send that particulate into the engine. On a base-end bypass with the same filter orientation, that isn't going to happen.

On my 5.4 the dome and the base are at nearly the same level (filter nearly horizontal). If we are going to play it out in our heads without really knowing exactly what happens, to me that means the contamination has nearly an equal chance of going thru either bypass location. We should keep in mind that illustration from Ford has to be looked at as a bit of a sales pitch. When you are trying to sell something, you accentuate your unique features and present them as, "This is better and you gotta have it." I believe there is sound engineering principle behind it and I don't argue against that. I only argue as to the weight we give it as a "vital feature." Two of the three engineers I spoke with had no horses in this game so I think their opinions were largely based on engineering rationale rather than sales. The third... it's possible there was some sales bias in it but basically his opinion was the same as the unbiased engineers so....

I'm certain Ford's is a sales pitch to some degree. But even if we are dealing with a filter that is close to horizontal, if the bypass happens right where the oil enters the filter (the media is further down the can) the chance for particulate that has settled off the media to wash into the clean side of the filter is significantly lower than if the oil runs the entire length of the can then heading out the bypass at the bottom of the media stack. Does it have a significant impact on the life of the engine? No idea. But for whatever reason, Ford has chosen to focus on it, so I think that at least lends some merit to giving pause and contemplating their reasoning. Otherwise it seems like an expense that they could easily avoid on their OEM filters And their marketing.... Well who are they marketing to? The minute percentage of the population that changes their own oil? Quick lube places? Hardly. It seems like a lot of expense for something that is going to have VERY poor ROI.

 

[ZeeOSix]

Originally Posted By: OVERKILL

I think here is our disconnect (I deleted the rest of the post because I think our terminology is just getting messed up here). The differential (delta-p) observed over the bypass valve is what I'm referencing here when I speak as to pressure (or the lack thereof) on the outlet side relative to the inlet side. Cold thick oil that can't go through the media at the volume it is delivered by the positive displacement pump (I think we are in agreement here) will result in a differential occurring.

Well of course ... but only if the delta-p is above the bypass valve setting. As said earlier, doesn't matter how the delta-p is created ... the bypass valve only operates from the delta-p across it.

Originally Posted By: OVERKILL

My point was that in a non-engulfed system (which you reference below with the surge comment, which was exactly what I was getting at) with cold oil, that differential is created between what is essentially the pressure in the can (15psi for example) and absolutely nothing, because there's no oil pressure established on the other side of the media creating our delta-p and causing our bypass event. Yes the pressure doesn't have to be 0, it could be ANYTHING as long as we have a differential, but in a non-engulfed engine, it will be zero or close to it. We on the same page now?

Not so sure we are on the same page with the "engulfed" stuff. An oiling system being "engulfed", "enveloped", etc or not shouldn't make any difference whatsoever to how the filter's bypass valve operates - the bypass valve only cares about delta-p across the media & valve itself. I think you're example of an "non-engulfed" engine is the same as my example of starting an engine with no oil in the filter or oil galleries - no? If an engine is started with a dry (non-filled) oiling system, the positive displacement oil pump sends down volume X of viscosity Y oil at idle speed, which flows through the filter first. If that combination of volume X and viscosity Y is enough to cause a delta-p greater than the bypass valve setting then the bypass valve opens. The viscosity of the oil is probably the biggest factor when cold and if the start-up if the engine is at idle speed. Of course, if the engine RPMs are increased much above idle with thick oil, the delta-p across the media is going to build pretty quickly. As a dry oiling system "envelopes", the engine's oil pressure starts to come up because the pump is now trying to force that same volume of oil through the more restrictive engine, but the delta-p across the filter media is not going to change because the PD pump is still pumping the same volume X of viscosity Y oil just as before. The engine oil pressure will of course rise up as a result of the oiling system envelopment as well as the pressure on both sides of the bypass valve within the filter ... but the delta-p across the oil filter will stay the same as long as the volume is still X and the viscosity is still Y.

Originally Posted By: OVERKILL

And here's where I was going earlier with my comments RE: Ford's design. With hot oil in a running engine, it doesn't matter. Particulate is already pressed against the media, so a bypass event is insignificant. HOWEVER, with an engine that has sat overnight and the sediment has settled to the bottom of the can (see the Ford PDF for their graphic of this) that initial surge/bypass event can, if the bypass is dome-end and the filter is mounted in the manner in which Ford depicts, send that particulate into the engine. On a base-end bypass with the same filter orientation, that isn't going to happen.

Good point about more danger/likelihood of ingesting debris through the bypass valve on a cold start scenario where debris might have sloughed off the media and collecting in the low point of the filter. I believe that once some debris has sloughed off the media and collected at the low point, it basically stays there if not disturbed. Depending on how far way the actual bypass valve is from the debris, it may not even get swept through the by-pass valve if it just cracks open now and then.

 

[dickwells]

Originally Posted By: 2010_FX4

Originally Posted By: dickwells

On the modular engine the base bypass is critical for the sideways mounted filter. When you have gon nuts trying to solve starved cam on one side only to find a hunk of crud blocking that little oriface you will use motorcraft from then on.

How does using a MC filter exclusively prevent this from happening? Are you suggesting the base end bypass is the only way to prevent it? What are the odds of this happening in a properly maintained engine? Just curious...

Well, when the bypass opens in a n MC the oil takes a shortcut in and out of the filter whereas in the other filters I am aware of the oil washes over the crud which has settled on the bottom side of the filter. In an upright filter the oil doesn't really wash over the crud which has settled to the bottom so it's not a big deal. I have always properly maintained my engines but on a few occasions I have seen bits of gaskets in the filter, just the thing to be easily moved up to the cams of a modular engine, which by the way has no cam bearings, the cam just running on machined places in the head. The odds I estimate as about 50 to 1, easily high enough for me to use Motorcraft which basically costs no more. Regards

 

[ZeeOSix]

Originally Posted By: dickwells

Originally Posted By: 2010_FX4

Originally Posted By: dickwells

On the modular engine the base bypass is critical for the sideways mounted filter. When you have gon nuts trying to solve starved cam on one side only to find a hunk of crud blocking that little oriface you will use motorcraft from then on.

How does using a MC filter exclusively prevent this from happening? Are you suggesting the base end bypass is the only way to prevent it? What are the odds of this happening in a properly maintained engine? Just curious...

Well, when the bypass opens in an MC the oil takes a shortcut in and out of the filter ...

Is it really a true short cut around any debris that might have collected at the base end if a MC filter was in a vertical base down orientation like shown below?

 

[OVERKILL]

Originally Posted By: ZeeOSix

Not so sure we are on the same page with the "engulfed" stuff. An oiling system being "engulfed", "enveloped", etc or not shouldn't make any difference whatsoever to how the filter's bypass valve operates

No, we are, you are just doing a better job of articulating it

Originally Posted By: OVERKILL

And here's where I was going earlier with my comments RE: Ford's design. With hot oil in a running engine, it doesn't matter. Particulate is already pressed against the media, so a bypass event is insignificant. HOWEVER, with an engine that has sat overnight and the sediment has settled to the bottom of the can (see the Ford PDF for their graphic of this) that initial surge/bypass event can, if the bypass is dome-end and the filter is mounted in the manner in which Ford depicts, send that particulate into the engine. On a base-end bypass with the same filter orientation, that isn't going to happen.

Good point about more danger/likelihood of ingesting debris through the bypass valve on a cold start scenario where debris might have sloughed off the media and collecting in the low point of the filter. I believe that once some debris has sloughed off the media and collected at the low point, it basically stays there if not disturbed. Depending on how far way the actual bypass valve is from the debris, it may not even get swept through the by-pass valve if it just cracks open now and then. [/quote] Thank you. And yes, this is where I think Ford was going/has gone with this whole thing. That debris, stirred up by that surge of oil on a cold start, might get swept through the bypass on a cold start. At least that's the impression I get Is it likely? Perhaps not. But they seem to have devoted a fair bit to it for whatever that's worth.

 

[OVERKILL]

Originally Posted By: ZeeOSix

Is it really a true short cut around any debris that might have collected at the base end if a MC filter was in a vertical base down orientation like shown below?

I think that's why Ford makes it a point to show their orientation in their media about how the bypass operates. Obviously it would be an epic failure on that Toyota and you'd want a dome-end bypass in that application.

 

[ZeeOSix]

Originally Posted By: OVERKILL

Originally Posted By: ZeeOSix

Is it really a true short cut around any debris that might have collected at the base end if a MC filter was in a vertical base down orientation like shown below?

I think that's why Ford makes it a point to show their orientation in their media about how the bypass operates. Obviously it would be an epic failure on that Toyota and you'd want a dome-end bypass in that application.

Yeah, a base end bypass might not be too good for a setup where the filter is mounted vertically and base down like on the Tacoma shown a few posts above. I brought of the question because I was just curious if the Motorcraft bypass valve actually kept the bypassing oil completely out of the dirty side of the media ... ie, does it bypass using some unique path that doesn't allow any debris from being swept into the bypass flow? I've never really cut open a MC filter with a base end bypass to scrutinize the exact design of the bypass valve.