Posting for DrDave, he will be along to explain:
Amsoil EA15K51 - 42,938 miles with UOA's and PC's
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So, after 42k+ miles only 0.0617g of debris was in the filter? Am I reading that right? Crazy.
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Love. it. So it looks like the optimal life in this app is around 35k. Love how you can see the PC drop with each successive oil change.
Originally Posted By: Xrs2zz
So, after 42k+ miles only 0.0617g of debris was in the filter? Am I reading that right? Crazy.
I would caution you to not read too much into that. I think we should read that as 0.0617g of material washed out of the filter media. It is unknown the mass of the material that was still in the filter mesh. However, I would think the majority of the particulate was washed from the filter.
Dave
So, after 42k+ miles only 0.0617g of debris was in the filter? Am I reading that right? Crazy.
I would caution you to not read too much into that. I think we should read that as 0.0617g of material washed out of the filter media. It is unknown the mass of the material that was still in the filter mesh. However, I would think the majority of the particulate was washed from the filter.
Dave
Interesting stuff, I'm just not used to seeing this type of report so don't have anything to compare to
So where's the explanation?
I’d like someone to explain something to me. In the 7,453 mile oci UOA, the number of particles greater than 4 microns fell from 113,507 to 4,500. Yet the iron count fell only from 10 to 8, and copper only from 8 ppm to 5; aluminum actually increased from 1 to 3; and lead stayed the same at 5 ppm. A similar phenomenon took place for the next UOA—the one for the 7,507 mile oci. Particles greater than 4 microns fell from 4,500 to 435, yet reported wear metals stayed close to the same.
Aren’t these sets of numbers supposed to be correlated? How could the overall number of particles plummet like this, but the wear metals stay close to the same?
The page I’m looking at is called the Analysis Report (upper right corner), page 1.
Aren’t these sets of numbers supposed to be correlated? How could the overall number of particles plummet like this, but the wear metals stay close to the same?
The page I’m looking at is called the Analysis Report (upper right corner), page 1.
There's a lot of things I don't understand about this data. For one, I don't get how particle counts are useful when you don't know what the rate of particle generation is to begin with. I mean, it'a snapshot in time of the particle count but it's constantly being filtered so what does that count mean really?
And what are the particles? I wouldn't think that all particles are damaging even if they were relatively large. What about fibers from the filter itself? Surely they aren't going to cause engine damage (and result in higher wear metals in the UOA). Without knowing exactly what the particles are how can you interpret the count?
"Largeish" particles will surely be captured relatively quickly by the filter within a short number of passes. So if you see those in the sample count, what does that mean? That the filter has failed or that there is a large number of them being produced? Look at it another way, if you had a count of zero does that mean that the filter is 100% efficient or that no particles are being introduced into the oil?
As to the correlation between wear metals and particles, again I don't know how you make that connection unless you know what the particles are. Is someone saying that particles of carbon or even silica cause iron wear? Even if they do, then you have to look at the engine from where the sample is obtained. For example in my BMW engine other than piston rings there is really very little iron that could wear. In this sample wouldn't iron numbers come from piston ring to liner (or block) contact rather than abrasive wear? Do metals that show up in an ICP or AA analysis only come from particle wear or rather from metal-to-metal contact? A large particle that causes wear may be generating wear metal pieces that are too large to be detected by ICP. Look at their comments saying the large particles are varnish and the minor is "dirt/grit" (whatever that is). Only the Trace is metal. Does the "Trace" show up on the ICP?
So I don't understand it either. I just think that particle count (even with historical data and trends) cannot necessarily be correlated to wear numbers, unless someone knows more than I do - which is likely.
And what are the particles? I wouldn't think that all particles are damaging even if they were relatively large. What about fibers from the filter itself? Surely they aren't going to cause engine damage (and result in higher wear metals in the UOA). Without knowing exactly what the particles are how can you interpret the count?
"Largeish" particles will surely be captured relatively quickly by the filter within a short number of passes. So if you see those in the sample count, what does that mean? That the filter has failed or that there is a large number of them being produced? Look at it another way, if you had a count of zero does that mean that the filter is 100% efficient or that no particles are being introduced into the oil?
As to the correlation between wear metals and particles, again I don't know how you make that connection unless you know what the particles are. Is someone saying that particles of carbon or even silica cause iron wear? Even if they do, then you have to look at the engine from where the sample is obtained. For example in my BMW engine other than piston rings there is really very little iron that could wear. In this sample wouldn't iron numbers come from piston ring to liner (or block) contact rather than abrasive wear? Do metals that show up in an ICP or AA analysis only come from particle wear or rather from metal-to-metal contact? A large particle that causes wear may be generating wear metal pieces that are too large to be detected by ICP. Look at their comments saying the large particles are varnish and the minor is "dirt/grit" (whatever that is). Only the Trace is metal. Does the "Trace" show up on the ICP?
So I don't understand it either. I just think that particle count (even with historical data and trends) cannot necessarily be correlated to wear numbers, unless someone knows more than I do - which is likely.
Firstly, who said that there was a correlation between particles and wear metals. As has been said all along, large "wear" particles don't get tested...it's oil analysis for the servicability of the oil, and checking that the unit is in proper condition rather than a "wear" comparative tool.
Particle counts are a measure of the effectiveness of the filter in ... removing particles.
You don't need to know whether the particle was 4041 steel, and came from the second ring on cylinder number three, nor whether the next one is shed in 10 seconds or next week...you are measuring the effectiveness of the filter at getting them out of circulation...more particles means more potentially damaging things in circulation.
New OTC oil is typically very dirty...it's good to know that the filter is getting rid of ANY particle...they (the filter) don't know or care what the particle is, they get rid of them.
Failing that, and following your logic, you need a "smart" filter that analyses and selectively removes particles, leaving the "safe" ones circulating.
Particle counts are a measure of the effectiveness of the filter in ... removing particles.
You don't need to know whether the particle was 4041 steel, and came from the second ring on cylinder number three, nor whether the next one is shed in 10 seconds or next week...you are measuring the effectiveness of the filter at getting them out of circulation...more particles means more potentially damaging things in circulation.
New OTC oil is typically very dirty...it's good to know that the filter is getting rid of ANY particle...they (the filter) don't know or care what the particle is, they get rid of them.
Failing that, and following your logic, you need a "smart" filter that analyses and selectively removes particles, leaving the "safe" ones circulating.
No, I don't need a smart filter any more than I need a particle count in general. But then the answer to paulri's question is that there is no link between a particle count and wear metals, that's what my post was referring to.
If all you are concerned about is "particles" and removing them then I agree a count will tell you that. But apparently it doesn't tell you anything more.
If all you are concerned about is "particles" and removing them then I agree a count will tell you that. But apparently it doesn't tell you anything more.
Greetings:
I've read your responses a couple of times trying to understand your points. I think you are making a couple of leaps in logic. I believe we have to look at both the filter analysis report and the UOA report. The information I glean from the data is that the filter becomes more efficient with time in service. This was actually my initial question to be answered by the data. I have been cautious to not introduce additional variables into the equation. I have not changed the air filter or even disturbed the housing. I have used the same oil for the last four changes. From lab #556 forward I have used the same oil. Pre #556 was M1 and post #556 is Amsoil 0w-30 Signature. The filter analysis report shows that it is capturing iron, apparently quite efficiently.
I don't believe we have the methodology to comment on wear rate or definitive source. We could identify the type of wear from the filter patch photographs if abnormal wear were occurring.
The purpose of this exercise was to explore the limits of filter efficiency vs. time in service. I believe that has been accomplished based on clear objective data. What I can say about this application, and quite possibly many others, is that changing the filter at each oil change is not necessary and may be counterproductive. During the first run the filter acts more like a screen than a filter. In this application it became a filter around 15k miles. I believe the voluminous talk and consideration people give to finding the most efficient filter is misdirected. I would hypothesize that the most efficient filter is the one already on your engine. If left to do it's job it becomes more efficient every pass. A filter lab tech told me years ago that people throw away their oil filters just when they are starting to get efficient.
The UOA report does not consider particle size in the spectrochemical analysis. I do not have the data to directly show that the wear metals on the report are
As always comments are welcome as well as objective hypothesis and critical thinking.
Happy motoring.
Dave
I've read your responses a couple of times trying to understand your points. I think you are making a couple of leaps in logic. I believe we have to look at both the filter analysis report and the UOA report. The information I glean from the data is that the filter becomes more efficient with time in service. This was actually my initial question to be answered by the data. I have been cautious to not introduce additional variables into the equation. I have not changed the air filter or even disturbed the housing. I have used the same oil for the last four changes. From lab #556 forward I have used the same oil. Pre #556 was M1 and post #556 is Amsoil 0w-30 Signature. The filter analysis report shows that it is capturing iron, apparently quite efficiently.
I don't believe we have the methodology to comment on wear rate or definitive source. We could identify the type of wear from the filter patch photographs if abnormal wear were occurring.
The purpose of this exercise was to explore the limits of filter efficiency vs. time in service. I believe that has been accomplished based on clear objective data. What I can say about this application, and quite possibly many others, is that changing the filter at each oil change is not necessary and may be counterproductive. During the first run the filter acts more like a screen than a filter. In this application it became a filter around 15k miles. I believe the voluminous talk and consideration people give to finding the most efficient filter is misdirected. I would hypothesize that the most efficient filter is the one already on your engine. If left to do it's job it becomes more efficient every pass. A filter lab tech told me years ago that people throw away their oil filters just when they are starting to get efficient.
The UOA report does not consider particle size in the spectrochemical analysis. I do not have the data to directly show that the wear metals on the report are
As always comments are welcome as well as objective hypothesis and critical thinking.
Happy motoring.
Dave
Thanks for your response. I guess I really don't understand how a multi-pass filter can be evaluated except on the basis of the smallest particle it will capture. I mean no filter is 100% inefficient at levels above the lowest threshold, so depending on the number of passes the filter has seen prior to the analysis that will determine the particles that are observed in the particle analysis. Even inefficient filters will capture particles eventually, correct? Assuming the size isn't below the lower threshold (a threshold I assume may move during use).
As to your comment that it stops iron, how would you know that? When I was in college and performed AA analysis on our fluid power department's oil samples, we knew what the largest particle size was that would show up in our analysis. A similar upper bound for ICP exists, and from what I have read it is around the 4 micron range unless an acid digestion is performed on the sample. Here is an article from Machinery Lubrication which mentions the limit:
http://www.machinerylubrication.com/Read/29657/wear-particle-analysis
Based on that I can't see how you would arrive at any correlation between iron and a particle count. Unless you know the particles observed in the particle analysis are indeed iron, and you know they are smaller than 4 microns, then that iron will not show up in the elemental analysis.
Originally Posted By: DrDave
Greetings:
I've read your responses a couple of times trying to understand your points. I think you are making a couple of leaps in logic. I believe we have to look at both the filter analysis report and the UOA report. The information I glean from the data is that the filter becomes more efficient with time in service. This was actually my initial question to be answered by the data. I have been cautious to not introduce additional variables into the equation. I have not changed the air filter or even disturbed the housing. I have used the same oil for the last four changes. From lab #556 forward I have used the same oil. Pre #556 was M1 and post #556 is Amsoil 0w-30 Signature. The filter analysis report shows that it is capturing iron, apparently quite efficiently.
I don't believe we have the methodology to comment on wear rate or definitive source. We could identify the type of wear from the filter patch photographs if abnormal wear were occurring.
The purpose of this exercise was to explore the limits of filter efficiency vs. time in service. I believe that has been accomplished based on clear objective data. What I can say about this application, and quite possibly many others, is that changing the filter at each oil change is not necessary and may be counterproductive. During the first run the filter acts more like a screen than a filter. In this application it became a filter around 15k miles. I believe the voluminous talk and consideration people give to finding the most efficient filter is misdirected. I would hypothesize that the most efficient filter is the one already on your engine. If left to do it's job it becomes more efficient every pass. A filter lab tech told me years ago that people throw away their oil filters just when they are starting to get efficient.
The UOA report does not consider particle size in the spectrochemical analysis. I do not have the data to directly show that the wear metals on the report are
As always comments are welcome as well as objective hypothesis and critical thinking.
Happy motoring.
Dave
As to your comment that it stops iron, how would you know that? When I was in college and performed AA analysis on our fluid power department's oil samples, we knew what the largest particle size was that would show up in our analysis. A similar upper bound for ICP exists, and from what I have read it is around the 4 micron range unless an acid digestion is performed on the sample. Here is an article from Machinery Lubrication which mentions the limit:
http://www.machinerylubrication.com/Read/29657/wear-particle-analysis
Based on that I can't see how you would arrive at any correlation between iron and a particle count. Unless you know the particles observed in the particle analysis are indeed iron, and you know they are smaller than 4 microns, then that iron will not show up in the elemental analysis.
Originally Posted By: DrDave
Greetings:
I've read your responses a couple of times trying to understand your points. I think you are making a couple of leaps in logic. I believe we have to look at both the filter analysis report and the UOA report. The information I glean from the data is that the filter becomes more efficient with time in service. This was actually my initial question to be answered by the data. I have been cautious to not introduce additional variables into the equation. I have not changed the air filter or even disturbed the housing. I have used the same oil for the last four changes. From lab #556 forward I have used the same oil. Pre #556 was M1 and post #556 is Amsoil 0w-30 Signature. The filter analysis report shows that it is capturing iron, apparently quite efficiently.
I don't believe we have the methodology to comment on wear rate or definitive source. We could identify the type of wear from the filter patch photographs if abnormal wear were occurring.
The purpose of this exercise was to explore the limits of filter efficiency vs. time in service. I believe that has been accomplished based on clear objective data. What I can say about this application, and quite possibly many others, is that changing the filter at each oil change is not necessary and may be counterproductive. During the first run the filter acts more like a screen than a filter. In this application it became a filter around 15k miles. I believe the voluminous talk and consideration people give to finding the most efficient filter is misdirected. I would hypothesize that the most efficient filter is the one already on your engine. If left to do it's job it becomes more efficient every pass. A filter lab tech told me years ago that people throw away their oil filters just when they are starting to get efficient.
The UOA report does not consider particle size in the spectrochemical analysis. I do not have the data to directly show that the wear metals on the report are
As always comments are welcome as well as objective hypothesis and critical thinking.
Happy motoring.
Dave
Originally Posted By: DrDave
Greetings:
I've read your responses a couple of times trying to understand your points. I think you are making a couple of leaps in logic. I believe we have to look at both the filter analysis report and the UOA report. The information I glean from the data is that the filter becomes more efficient with time in service. This was actually my initial question to be answered by the data. I have been cautious to not introduce additional variables into the equation. I have not changed the air filter or even disturbed the housing. I have used the same oil for the last four changes. From lab #556 forward I have used the same oil. Pre #556 was M1 and post #556 is Amsoil 0w-30 Signature. The filter analysis report shows that it is capturing iron, apparently quite efficiently.
I don't believe we have the methodology to comment on wear rate or definitive source. We could identify the type of wear from the filter patch photographs if abnormal wear were occurring.
The purpose of this exercise was to explore the limits of filter efficiency vs. time in service. I believe that has been accomplished based on clear objective data. What I can say about this application, and quite possibly many others, is that changing the filter at each oil change is not necessary and may be counterproductive. During the first run the filter acts more like a screen than a filter. In this application it became a filter around 15k miles. I believe the voluminous talk and consideration people give to finding the most efficient filter is misdirected. I would hypothesize that the most efficient filter is the one already on your engine. If left to do it's job it becomes more efficient every pass. A filter lab tech told me years ago that people throw away their oil filters just when they are starting to get efficient.
The UOA report does not consider particle size in the spectrochemical analysis. I do not have the data to directly show that the wear metals on the report are
As always comments are welcome as well as objective hypothesis and critical thinking.
Happy motoring.
Dave
I didn't see you comment in the linked thread below, but what you have seen here and what's discussed in the linked thread pretty much correlate.
http://www.bobistheoilguy.com/forums/ubb...ime#Post4126448
Greetings:
I've read your responses a couple of times trying to understand your points. I think you are making a couple of leaps in logic. I believe we have to look at both the filter analysis report and the UOA report. The information I glean from the data is that the filter becomes more efficient with time in service. This was actually my initial question to be answered by the data. I have been cautious to not introduce additional variables into the equation. I have not changed the air filter or even disturbed the housing. I have used the same oil for the last four changes. From lab #556 forward I have used the same oil. Pre #556 was M1 and post #556 is Amsoil 0w-30 Signature. The filter analysis report shows that it is capturing iron, apparently quite efficiently.
I don't believe we have the methodology to comment on wear rate or definitive source. We could identify the type of wear from the filter patch photographs if abnormal wear were occurring.
The purpose of this exercise was to explore the limits of filter efficiency vs. time in service. I believe that has been accomplished based on clear objective data. What I can say about this application, and quite possibly many others, is that changing the filter at each oil change is not necessary and may be counterproductive. During the first run the filter acts more like a screen than a filter. In this application it became a filter around 15k miles. I believe the voluminous talk and consideration people give to finding the most efficient filter is misdirected. I would hypothesize that the most efficient filter is the one already on your engine. If left to do it's job it becomes more efficient every pass. A filter lab tech told me years ago that people throw away their oil filters just when they are starting to get efficient.
The UOA report does not consider particle size in the spectrochemical analysis. I do not have the data to directly show that the wear metals on the report are
As always comments are welcome as well as objective hypothesis and critical thinking.
Happy motoring.
Dave
I didn't see you comment in the linked thread below, but what you have seen here and what's discussed in the linked thread pretty much correlate.
http://www.bobistheoilguy.com/forums/ubb...ime#Post4126448
Thinking about this a little more, if you are observing decreased iron levels in your ICP analysis and it is due to the filter, then a corresponding decrease in the sub 4-micron particle count should also be observed, correct?
And sorry, although the article I linked was informative and did mention the upper bound size for ICP, this is the article I intended to link:
http://www.machinerylubrication.com/Read/28974/particles-friend-foe
Quote:
Ionization Energy and Spectrometric Analysis
The available ionization energy to energize large particles reaches a plateau, which is one of the reasons different spectrometric methods have limitations concerning particle size (3 microns maximum for ICP and 8 to 10 microns maximum for an RDE spectrometer).
Spectrometers, as they are applied today, are blind to large particles. Traditional methods of determining large particles (larger than 10 microns) are acid digestion (expensive and hazardous), microwave digestion (expensive and time consuming) and direct ferrography (does not include non-ferrous metals).
And sorry, although the article I linked was informative and did mention the upper bound size for ICP, this is the article I intended to link:
http://www.machinerylubrication.com/Read/28974/particles-friend-foe
Quote:
Ionization Energy and Spectrometric Analysis
The available ionization energy to energize large particles reaches a plateau, which is one of the reasons different spectrometric methods have limitations concerning particle size (3 microns maximum for ICP and 8 to 10 microns maximum for an RDE spectrometer).
Spectrometers, as they are applied today, are blind to large particles. Traditional methods of determining large particles (larger than 10 microns) are acid digestion (expensive and hazardous), microwave digestion (expensive and time consuming) and direct ferrography (does not include non-ferrous metals).
The following probably isn't necessary at all, but then again this is BITOG:
Just to illustrate wear metal rates in terms of ppm/thousand miles, I went ahead and looked at three wear metals that had numbers for all the OCIs (instead of
Yes, there are possible changes in conditions that might have helped create better wear results later on in this filter's life. But it is hard to say that leaving that filter in, hurt the engine in any way, and barring any further comment from DrDave about any changes in his driving conditions, it strongly suggests that the filter itself was doing a much better job preventing engine wear, as it was left in.
Just to illustrate wear metal rates in terms of ppm/thousand miles, I went ahead and looked at three wear metals that had numbers for all the OCIs (instead of
Yes, there are possible changes in conditions that might have helped create better wear results later on in this filter's life. But it is hard to say that leaving that filter in, hurt the engine in any way, and barring any further comment from DrDave about any changes in his driving conditions, it strongly suggests that the filter itself was doing a much better job preventing engine wear, as it was left in.
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Originally Posted By: paulri
I’d like someone to explain something to me. In the 7,453 mile oci UOA, the number of particles greater than 4 microns fell from 113,507 to 4,500. Yet the iron count fell only from 10 to 8, and copper only from 8 ppm to 5; aluminum actually increased from 1 to 3; and lead stayed the same at 5 ppm. A similar phenomenon took place for the next UOA—the one for the 7,507 mile oci. Particles greater than 4 microns fell from 4,500 to 435, yet reported wear metals stayed close to the same.
Aren’t these sets of numbers supposed to be correlated? How could the overall number of particles plummet like this, but the wear metals stay close to the same?
The page I’m looking at is called the Analysis Report (upper right corner), page 1.
This may help you understand why particle count and ppm may not correlate and why simple UOA cannot be used for determining wear:
Let's talk about the size of the particles that make it into the plasma. You've probably read many times that ICP can see wear particles at about 5 microns. The labs will tell you this also. They are wrong.
The particle size is based on the aerodynamic diameter, not the actual diameter. An ICP is designed to have a hard cut off of 4.5-5.0 microns due to the fact that droplets larger than that destabilize the plasma. That's where the 5 micron figure comes from. The problem is that is the aerodynamic diameter and is based on a spherical droplet of water. Aerodynamic diameter is affected by density and shape. Metals have a higher density than water, therefore smaller particles are required to achieve the same aerodynamic diameter and be allowed to pass through to the plasma.
This is one of the many reasons why "wear metals" do not serve as a good indicator of wear. The ICP only sees a portion of "normal" wear and miss most if not all of the larger particles generated by abnormal and break-in wear. The other is that due to the different densities of the metals the instrument does not see them equally. Given an equal amount and distribution of particle sizes, the ICP could read 4X as much aluminum as lead due to the density difference between the two. An accurate measure of what is in the oil can only be made if the oil undergoes a digestion to put the metals in solution.
The first 5 pages of this presentation cover what I have talked about. The illustration at the top of page 5 shows the relationship visually. They use a material with a density of 4000 kg/m3 for illustration. Aluminum, depending on alloy has a density of about 2700-2800, copper 8940, iron/steel 7850, and lead 11340. Visualize the 4000 kg/m3 circles at half that size and that is roughly the relative size of an iron particle that an ICP can see vs the 4.5 micron water droplet.
Ed
I’d like someone to explain something to me. In the 7,453 mile oci UOA, the number of particles greater than 4 microns fell from 113,507 to 4,500. Yet the iron count fell only from 10 to 8, and copper only from 8 ppm to 5; aluminum actually increased from 1 to 3; and lead stayed the same at 5 ppm. A similar phenomenon took place for the next UOA—the one for the 7,507 mile oci. Particles greater than 4 microns fell from 4,500 to 435, yet reported wear metals stayed close to the same.
Aren’t these sets of numbers supposed to be correlated? How could the overall number of particles plummet like this, but the wear metals stay close to the same?
The page I’m looking at is called the Analysis Report (upper right corner), page 1.
This may help you understand why particle count and ppm may not correlate and why simple UOA cannot be used for determining wear:
Let's talk about the size of the particles that make it into the plasma. You've probably read many times that ICP can see wear particles at about 5 microns. The labs will tell you this also. They are wrong.
The particle size is based on the aerodynamic diameter, not the actual diameter. An ICP is designed to have a hard cut off of 4.5-5.0 microns due to the fact that droplets larger than that destabilize the plasma. That's where the 5 micron figure comes from. The problem is that is the aerodynamic diameter and is based on a spherical droplet of water. Aerodynamic diameter is affected by density and shape. Metals have a higher density than water, therefore smaller particles are required to achieve the same aerodynamic diameter and be allowed to pass through to the plasma.
This is one of the many reasons why "wear metals" do not serve as a good indicator of wear. The ICP only sees a portion of "normal" wear and miss most if not all of the larger particles generated by abnormal and break-in wear. The other is that due to the different densities of the metals the instrument does not see them equally. Given an equal amount and distribution of particle sizes, the ICP could read 4X as much aluminum as lead due to the density difference between the two. An accurate measure of what is in the oil can only be made if the oil undergoes a digestion to put the metals in solution.
The first 5 pages of this presentation cover what I have talked about. The illustration at the top of page 5 shows the relationship visually. They use a material with a density of 4000 kg/m3 for illustration. Aluminum, depending on alloy has a density of about 2700-2800, copper 8940, iron/steel 7850, and lead 11340. Visualize the 4000 kg/m3 circles at half that size and that is roughly the relative size of an iron particle that an ICP can see vs the 4.5 micron water droplet.
Ed
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