Patman
Staff member
I'm very interested to see this next round of testing! Looks like that Fram filter is restrictive after all. The first one you tested must've been in complete bypass mode.
BOBISTHEOILGUY FILTER TESTS
- Thread starter BOBISTHEOILGUY
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I know this is a work in progress and I've been happy to send one of the Bypass systems but....The PSID is SHOCKING. Bob you say both are showing the same difference. No wonder our oil analysis results with the Dual Remote were so poor. I have to wonder if there is something in the shuttle valve causing problems ? Any Amsoil tech people want to chime in to help figure this out? We tested an 4.3 chevy V6 for 33,000 miles before ceasing the test with what we thought was oil issues maybe the oil was eaten by reduced flow issues ?
Interesting enough as I really don't know how to explain the drop across the bypass system. It'd be interesting to test some other bypass designs in comparision.
As for the variac, it is nothing more than a 120vac variac which in relative to vdc output, so the meter is showing that I had to either increase or decrease the VAC input to achive the 40lb input pressure.
I'd have to agree patman with what you're saying about the flow of the fram. It appears that at the 70deg oil it was in bypass where as the others may not have been. now at the 80deg temps, fram is now in regular flow, thus reading the drop across the media instead of the bypass?
[ May 21, 2003, 06:54 PM: Message edited by: BOBISTHEOILGUY ]
As for the variac, it is nothing more than a 120vac variac which in relative to vdc output, so the meter is showing that I had to either increase or decrease the VAC input to achive the 40lb input pressure.
I'd have to agree patman with what you're saying about the flow of the fram. It appears that at the 70deg oil it was in bypass where as the others may not have been. now at the 80deg temps, fram is now in regular flow, thus reading the drop across the media instead of the bypass?
[ May 21, 2003, 06:54 PM: Message edited by: BOBISTHEOILGUY ]
MolaKule
Staff member
I may still have a dual bypass at home. If I do, will check it and see if we can determine what gives?
Patman
Staff member
It'll be very interesting to see how the flow changes with hot oil, will the ones that shined in the cold oil testing previously now end up being the opposite? Stay tuned!
WHOAAAAAAAAAAAAAAAAAAAAAAAAAAAA slow down people...
Again read my post (lately - why have people been skipping what I write and what I ask???)
Does no ONE find it odd that the pressure delta across both dual set-ups is almost the same?
Does no one have the answer as how the bypass filter was adapted?
BOB- keep ALL the plumbing the same. Remove the dual unit BUT just connect the two lines (inlet and outlet) together. Understand? No filter, but you can measure the plumbing pressure drop.
My dual mount IS different than the cast one you show, but I have VERY little pressure drop across it and my OP is higher with that set-up than with just a filter......................!
EDIT => IS that second one a Bypass set-up or is it just a dual remote?? Maybe that's what I'm baffled on.....
[ May 21, 2003, 08:23 PM: Message edited by: Pablo ]
Again read my post (lately - why have people been skipping what I write and what I ask???)
Does no ONE find it odd that the pressure delta across both dual set-ups is almost the same?
Does no one have the answer as how the bypass filter was adapted?
BOB- keep ALL the plumbing the same. Remove the dual unit BUT just connect the two lines (inlet and outlet) together. Understand? No filter, but you can measure the plumbing pressure drop.
My dual mount IS different than the cast one you show, but I have VERY little pressure drop across it and my OP is higher with that set-up than with just a filter......................!
EDIT => IS that second one a Bypass set-up or is it just a dual remote?? Maybe that's what I'm baffled on.....
[ May 21, 2003, 08:23 PM: Message edited by: Pablo ]
We did keep it exactly the same. Just for everyones info, when we first hooked them up, we confused ourselves and had the in and out crossed. After not getting any pressure out, we swapped them and then was able to get the 13lb output you see.
I honestly don't see why would we need to check the hoses for flow as both sets of hoses are just that, straight through. As pictured on our first picture with our gutted out fram, that shows the basic plumbing of our system without any restrictions and the only thing by running a hose from in to out would not accomplish any more than the first picture with the gutted filter.
I honestly don't see why would we need to check the hoses for flow as both sets of hoses are just that, straight through. As pictured on our first picture with our gutted out fram, that shows the basic plumbing of our system without any restrictions and the only thing by running a hose from in to out would not accomplish any more than the first picture with the gutted filter.
There is now more plumbing.
The screw on adapter, those fittings, the hose and the fittings to dual filter.
Is that second one a mount for a by-pass? Never seen that kind. If not how did the bypass filter screw on? Is that an older Amsoil design before they came out with the machined dual block?
Are you going to try a "regular" dual mount? - because frankly I'm not the only one that doesn't know what the second unit is.
The screw on adapter, those fittings, the hose and the fittings to dual filter.
Is that second one a mount for a by-pass? Never seen that kind. If not how did the bypass filter screw on? Is that an older Amsoil design before they came out with the machined dual block?
Are you going to try a "regular" dual mount? - because frankly I'm not the only one that doesn't know what the second unit is.
Let me see if I can help you see what I see.
I went out and tore things apart so we can see how this thing works.
First, the main connection to the oil filter attachment, has no plumbing except in and out and through a hose, so there's no way there'd be any pressure drop across that.
Here's where the problem is IMO.....
Notice, that the input side goes straight through to the back filter where there is a ball and spring check valve. Looking at this picture, the bypass filter fits on the left(has the big thread) the full flow mounts on the left. This valve is in the back where the full flow filter fits. The bypass filter seems to have full flow from the input but the restriction is at the full flow input.
Here is a straight through view, left one is the input side of the oil and right is output.
Here is a picture of the newer machined unit, again, see where the pressure valve is....
Is it possible that the bigger filter suppose to be a full flow? It would make more sense to me that the filter after the check valve would be the bypass filter. Seems you have to over come the pressure of that spring in order to get full flow, other wise it is going through the bypass filter.
Does that help explain what is happening?
I went out and tore things apart so we can see how this thing works.
First, the main connection to the oil filter attachment, has no plumbing except in and out and through a hose, so there's no way there'd be any pressure drop across that.
Here's where the problem is IMO.....
Notice, that the input side goes straight through to the back filter where there is a ball and spring check valve. Looking at this picture, the bypass filter fits on the left(has the big thread) the full flow mounts on the left. This valve is in the back where the full flow filter fits. The bypass filter seems to have full flow from the input but the restriction is at the full flow input.
Here is a straight through view, left one is the input side of the oil and right is output.
Here is a picture of the newer machined unit, again, see where the pressure valve is....
Is it possible that the bigger filter suppose to be a full flow? It would make more sense to me that the filter after the check valve would be the bypass filter. Seems you have to over come the pressure of that spring in order to get full flow, other wise it is going through the bypass filter.
Does that help explain what is happening?
First I REALLY want to thank you!! No need to hurry on my account. I want folks to know you really go the extra mile.
I think there still would be a minor pressure drop - and mainly I was questioning why both are the same huge pressure delta. However you more than answered my question - or explained rather well what is happening. I partially agree with you - and I seem to remember someone writing last year or so on the topic.
Let me see if I can explain. On the surface what you say makes total sense to me. Why meter the oil to the full flow filter and have unrestricted flow to the by-pass? I think (and I'm speculating here) the original engineers set out to keep a constant pressure at the by-pass and when the pressure goes higher than the spring pressure it lets oil go through. Makes some sense if the spring pressure is real low......but I'm real glad I just have a simple dual filter (NOT a by-pass)
Thanks again for being the Oilguy!
I think there still would be a minor pressure drop - and mainly I was questioning why both are the same huge pressure delta. However you more than answered my question - or explained rather well what is happening. I partially agree with you - and I seem to remember someone writing last year or so on the topic.
Let me see if I can explain. On the surface what you say makes total sense to me. Why meter the oil to the full flow filter and have unrestricted flow to the by-pass? I think (and I'm speculating here) the original engineers set out to keep a constant pressure at the by-pass and when the pressure goes higher than the spring pressure it lets oil go through. Makes some sense if the spring pressure is real low......but I'm real glad I just have a simple dual filter (NOT a by-pass)
Thanks again for being the Oilguy!
MolaKule
Staff member
The wrong filter on the wrong side could the reason for the pressure anamolies.
My old dual remote had an adapter on the full flow filter which fed oil via two hoses to the dual remote system which had one by-pass filter and one full flow. The by-pass side was a simple brass orifice drilled to limit flow through the by-pass. No pressure springs in the dual-remote head.
My old dual remote had an adapter on the full flow filter which fed oil via two hoses to the dual remote system which had one by-pass filter and one full flow. The by-pass side was a simple brass orifice drilled to limit flow through the by-pass. No pressure springs in the dual-remote head.
Well, Having thought about it, that can't be the case here as first, the full and bypass have different size center threads, so no way to install incorrect filter on the other. In the once situation, we had left the bypass filter that was alread on it on, so no way we missed that as well, so given these factors, I do believe that this pressure valve they have is what is causing the increase of backpressure and lack of flow on the other side.
Please understand, I am not picking on amsoil, but am just showing the results I got on this unit, and being two seperate models, both with the same results, really made me wonder.
If I get my hands on another style of bypass filtration then maybe we can see how it reacts, although I suspect the plumbing will be different than this case.
I heard from a long time ago, when filters were not even on engines, that fram? came out with a filter system, but when installed they started to lose lower bearings mainly due to the fact it parralled they oil system which reduced oil flow.
Some interesting history.
Isn’t it normal for the pressure to drop in the dual bypass arrangement? In particular, if the fluid is moving horizontally, the pressure ‘p’ will be lower where the fluid is moving faster (Bernoulli equation).
With the single filter setup, the filter is restricting the flow volume. When the bypass filter setup is used with dual filters, the flow volume will increase. If the flow volume increases and the orifices haven’t changed, then the velocity of the flow has to increase, which means the pressure will drop where ever velocity increases. I believe this is what you’re seeing.
If you installed a flow meter at the output that measured the flow of oil in gallons per minute, you should see a larger ‘volume’ of oil flowing the from dual filter setup as opposed to the single filter setup.
[ May 22, 2003, 01:25 PM: Message edited by: qadsan ]
With the single filter setup, the filter is restricting the flow volume. When the bypass filter setup is used with dual filters, the flow volume will increase. If the flow volume increases and the orifices haven’t changed, then the velocity of the flow has to increase, which means the pressure will drop where ever velocity increases. I believe this is what you’re seeing.
If you installed a flow meter at the output that measured the flow of oil in gallons per minute, you should see a larger ‘volume’ of oil flowing the from dual filter setup as opposed to the single filter setup.
[ May 22, 2003, 01:25 PM: Message edited by: qadsan ]
1st great forum and great post (wow 5 pages)... my problem...why do you feel that presure differential is an indicator of filter effectiveness? We see that the empty FRAm filter has low pressure drop compared to the Fram with the filter element in it...so far so good...but what would the results be if you doubled the area of the filter element,ie the filter element is twice as long. This would yield a greater area for the oil to flow through at the same pressure, which at a constant flow rate would half the presure differential! If you connected 2 filters in parallel...the same presure acting on each...it would be intersting to see...what the pressure diferential would be. I think the hydralic equation elsewhere inthis post bears this out. ps a link to a site that has the visual comparisons between cut appart filters. http://www.scuderiaciriani.com/rx7/oil_filter_study/ Regardless, great discusion!
MolaKule
Staff member
What about the thread adapter. Is it srewed too far up into the housing and restricting flow???
MolaKule
Staff member
Are the hoses on the wrong side of the dual filter head or does it matter.
To have that much pressure differential "across" the head, require a massive restriction of flow.
I think Pablo may have had it right the first time.
To have that much pressure differential "across" the head, require a massive restriction of flow.
I think Pablo may have had it right the first time.
I think that there is a total misunderstanding of the operation of the bypass vavle in any oil filter. A bypass valve opens when the pressure differential reaches the set point and stays open as long as the pressure differential is maintained.
If the pressure differential is below the bypass point, the valve will always be closed. That's because they are spring loaded. The pressure of the oil must exceed the pressure exerted by the spring to open the valve and keep the valve open. There must be differential oil pressure to have an open bypass valve.
Therefore, it is impossible to say that a filter had low differential pressure because it was in the bypass mode.
Tom
If the pressure differential is below the bypass point, the valve will always be closed. That's because they are spring loaded. The pressure of the oil must exceed the pressure exerted by the spring to open the valve and keep the valve open. There must be differential oil pressure to have an open bypass valve.
Therefore, it is impossible to say that a filter had low differential pressure because it was in the bypass mode.
Tom
Let me see if I can explain this in another way...
First the picture..
ok, as you look at it, there are only two channels. First, I blew air through the input side and when blocking off the first hole, it stop allowing air to flow until I removed the ball and check valve. Ok, now, once the restriction was removed, it was free flowing.
I then applied air through the output and covered each of the center threaded holes and both were unrestricted. Once both were covered there was no flow.
Now that I had established air flow through this part, I also took pictures so you could see where on the left side(input) there was a clear shot directly through the line.
Ok, hoses, let's see how to explain the hoses,.... What is a function of a hose?. it is a way for a fluid(in this case) to travel through. Are there hoses (rubber not metal)that are design to cause a restriction of flow?. Well, in this case, both hoses are completely clear of all obstacles, and neither had any restriction. So, even if the hoses were reversed, how would that affect the flow?... ok, went out and took pics on the head and hoses. First, notice the hose numbers here.. Both the same...
Here is the head assembly where this matches up to the oil filter plumbing on the engine.
Notice, nothing but straight through, no restrictions.
Ok, now let's think about how this works...
Bypass filter is the filter on this block, unrestricted from flow direct from the oil pump. The pressure valve is between the bypass filter and the full flow filter. Now, something I failed to mention earlier, we also ran this setup with our gutted out fram and the psi was the same. So, conclusion, the full flow was not getting flow and that the 13psi is coming from the bypass filter only.
Here is the problem with this setup, the oil pump has a pressure relief valve similar to the pressure valve in the bypass system shown. Now, what is the pressure that it takes to over come the pressure to go into the full flow filter? Is it higher or lower than the pressure over flow valve located in the oil pump?. Why couldn't we overcome the valve with 40lbs of oil pressure against either one of them?
I also verified that the bypass filter is the filter closest to the input/output lines.
First the picture..
ok, as you look at it, there are only two channels. First, I blew air through the input side and when blocking off the first hole, it stop allowing air to flow until I removed the ball and check valve. Ok, now, once the restriction was removed, it was free flowing.
I then applied air through the output and covered each of the center threaded holes and both were unrestricted. Once both were covered there was no flow.
Now that I had established air flow through this part, I also took pictures so you could see where on the left side(input) there was a clear shot directly through the line.
Ok, hoses, let's see how to explain the hoses,.... What is a function of a hose?. it is a way for a fluid(in this case) to travel through. Are there hoses (rubber not metal)that are design to cause a restriction of flow?. Well, in this case, both hoses are completely clear of all obstacles, and neither had any restriction. So, even if the hoses were reversed, how would that affect the flow?... ok, went out and took pics on the head and hoses. First, notice the hose numbers here.. Both the same...
Here is the head assembly where this matches up to the oil filter plumbing on the engine.
Notice, nothing but straight through, no restrictions.
Ok, now let's think about how this works...
Bypass filter is the filter on this block, unrestricted from flow direct from the oil pump. The pressure valve is between the bypass filter and the full flow filter. Now, something I failed to mention earlier, we also ran this setup with our gutted out fram and the psi was the same. So, conclusion, the full flow was not getting flow and that the 13psi is coming from the bypass filter only.
Here is the problem with this setup, the oil pump has a pressure relief valve similar to the pressure valve in the bypass system shown. Now, what is the pressure that it takes to over come the pressure to go into the full flow filter? Is it higher or lower than the pressure over flow valve located in the oil pump?. Why couldn't we overcome the valve with 40lbs of oil pressure against either one of them?
I also verified that the bypass filter is the filter closest to the input/output lines.
KCTOM,
We are not talking about bypass valves in full flow filters, which is what you appear to be. This is a bypass filter and a full flow filter attached to the engine via the full flow filter location on the engine.
We are not talking about bypass valves in full flow filters, which is what you appear to be. This is a bypass filter and a full flow filter attached to the engine via the full flow filter location on the engine.
Several suggestions:
1. Start a new thread. Begin by testing individual, branded filters for pressure drops. We have a baseline now, for an empty filter can, of about 1 psi. Build on this.
2. Measure oil output for each filter in units of volume/time, and correlate these data with pressure drop.
3. Do the same thing again, but with oil heated to a typical operating temperature.
4. Save testing of the bypass device for later.
1. Start a new thread. Begin by testing individual, branded filters for pressure drops. We have a baseline now, for an empty filter can, of about 1 psi. Build on this.
2. Measure oil output for each filter in units of volume/time, and correlate these data with pressure drop.
3. Do the same thing again, but with oil heated to a typical operating temperature.
4. Save testing of the bypass device for later.
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