Bypass Filtration Article

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slalom44

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Here's an interesting article in "Machinery Lubrication", a publication of the Noria Corporation. It is titled, "Understanding Engine Oil Bypass Filtration".
http://www.machinerylubrication.com/Read/29026/engine-bypass-filtration

One particular sentence worth noting in the attached article is the following:

In a case study performed by General Motors and published by the Society of Automotive Engineers (SAE), it was determined that engine service life could be extended eight times when 5-micron filtration is implemented vs. the standard 40-micron filtration.

Granted, standard automotive filters are considered better than "40-micron filtration", but this study implies that there is a significant benefit to having bypass filtration over the life of an engine using bypass filtration.

There is a common feeling by many BITOGers (that have posted on this forum) that the primary benefit of bypass filtration is extended OCIs. Most people don't keep their vehicle long enough to realize the extended engine life that bypass filtration offers. But I disagree: In my opinion, the primary benefit is engine longevity, and extended OCIs is an added benefit.
 
Originally Posted By: FXjohn
when was the last time you heard of an engine having an oil related failure?

I've had several: One car started to burn lots of oil. It wasn't cost effective to rebuild the engine, so I just got rid of it. Another car became very hard to start, which I found to be caused by very low oil compression. It also burned oil. Again, it was the reason I got rid of it.

I can find many threads on other forums that discuss low oil pressure due to worn bearings and excessive oil consumption due to worn rings. When someone gets these symptoms, they either have to drop a wad of money to rebuild/replace the engine, or (depending on the car's value) scrap the car.

Oil related failures aren't catastrophic. They are gradual, and require a great deal of money to fix. I have 274,000 miles on my Honda S2000 with a bypass system, and the engine shows no signs of wear. There are only a handful of S2000 engines with as many miles. And just because the others are still running doesn't mean they don't have bearing and ring wear.
 
First, we don't know which paper was being quoted.

The usual suspect is Staley's "Correlating Lube Oil Filtration Efficiencies With Engine Wear" SAE paper # 881825 published in 1988. If so, the quote is somewhat misleading because the test consisted of injecting 50 grams of AC Fine Dust into the lube system every hour for 8 hours while the engine was loaded and running on a dyno. That would be a total of 400 grams of dust. Four different levels of 98% filtration were tested, 40, 15, 8.5 and 7 um and the filters were changed when differential pressure indicated the filters were getting near their max DP. In the end, with the filters being near absolute at those micron ratings, you got to see how much wear was generated with the oil loaded with however many grams of material in the sizes smaller than the filtration level used.

The problem with drawing too many general or broad conclusions about this is that 400 grams of material into the oil is probably a lifetime double accumulation for the average engine. I am using a generic figure of an engine generating and ingesting .0013 grams of contaminants per 1000 miles, for a total of 260 grams in 200K miles. The oil in the test engines (6V53 Detroit and Pontiac Iron Duke 4) contained a MUCH higher concentration of contaminants than the vast, vast (did I say VAST) majority of engines would ever deal with or be allowed to deal with. No real world engine would ever be ingesting 50 grams of contamination per hour. Most car & light truck oil filters have a capacity of under 20 grams. Few are loaded to over 50% at the OCI/FCI and most don't even get there.

The study is accurate in measuring the wear effects of a high rate and level of contamination but it is incorrect to assume much of that applies to a real world engine that has next to no contamination at the end of a 5, 7.5 or 10K OCI.

If the contamination inputs are controlled, i.e. a tight and well filtered intake system, relatively clean fuel and a reasonable operational cycle, the engine itself generates next to no contamination via it's own wear... once broken in of course. While it's true that wear is less the cleaner the oil, at the very low levels of contamination seen by well maintained, non-commercial engines like most of us here operate, the benefits bypass systems that don't usually return the investment in terms of lower wear... at all or in any reasonable time period. The more tangible benefit is the OCI extension and that's how you pay for the bypass system. That is the assertion of many of us on BITOG, who think it, not feel it.
 
At startup will there be a lag in flow as the pump strains to push oil a longer distance through smaller than standard filter media holes? Or is there a priming mechanism?
 
Originally Posted By: slalom44
Originally Posted By: FXjohn
when was the last time you heard of an engine having an oil related failure?

I've had several: One car started to burn lots of oil. It wasn't cost effective to rebuild the engine, so I just got rid of it. Another car became very hard to start, which I found to be caused by very low oil compression. It also burned oil. Again, it was the reason I got rid of it.

I can find many threads on other forums that discuss low oil pressure due to worn bearings and excessive oil consumption due to worn rings. When someone gets these symptoms, they either have to drop a wad of money to rebuild/replace the engine, or (depending on the car's value) scrap the car.

Oil related failures aren't catastrophic. They are gradual, and require a great deal of money to fix. I have 274,000 miles on my Honda S2000 with a bypass system, and the engine shows no signs of wear. There are only a handful of S2000 engines with as many miles. And just because the others are still running doesn't mean they don't have bearing and ring wear.


I haven't heard f oil related problems since the 70's. I have a truck with 340,000 and "no signs of wear". just oil changes with mobil one twice a year.
 
I would theorize that Slalom being so far ahead of the curve in terms of wear vs his S2000 compadres is due as much to his obvious attention to detail and choice of good products as it is to the fact that he has a bypass filter installed. It's certainly a contributing factor, along with the preluber and, most likely, a top quality oil and, again, attention to detail.

In case someone is playing "Hun From the Sun" and planning to attack, realize I am running bypass systems on two of my vehicles. I am nearing the end of a 15K test on dino oil on the gasser. I had the oil analyzed at 5K, 10K and despite having 5 um absolute bypass filtration from 5K to 10K combined with a 99% @ 20 um primary filter, there was nothing particularly remarkable about the oil at 10K vs a similar truck without bypass. If you look at 2010FX4's recent 10K UOA, for example, I could not say my 10K dino oil was remarkably better than his 10K dino oil.

I did a PC and he did not, so we can not compare contamination levels. Overall, the 10K PC was some better than the 5K PC done before the system was installed, though better in the upper size particulates. At 10K, I switched the element to a 3um unit and we'll see if there are any noteworthy changes.

I think the reason my tests are unremarkable in comparison to 2010FX4, and others (same Ford F150 5.4L application) is that the contamination inputs have been controlled in all cases. Neither are any of these engines being operated in what might be considered severe conditions... i.e. heavy loads, high engine loads, dirty, dusty conditions or problems like poor air filtration that would increase contamination rates or levels. Add these factors to any engine and bypass filtration makes more sense.

As an aside, I will also say I think bypass filtration makes much more economic sense with a diesel. Especially the soot monsters the modern EGR equipped diesels have become. Anything you can do to reduce the soot load is a good thing. The oil additives go a long way towards preventing soot agglomeration but in some cases, I am hearing about sudden flips where the oil is fine but reaches a tipping point quite rapidly to where it becomes a problem. I think this is why the OCI dropped a bit with the newer engines, along with regen and fuel dilution. Operational issues are paramount here but a bypass offers a bit of an equalizer. FYI, I have a diesel with a bypass and will be doing an 8K OCI right after an overhaul (no break-in oil change). A 2K UOA and PC was very encouraging and I decided to just leave the oil in for a full 8K run, though I did change from 10 10 um to a 3 up bypass element (the 10 um was recommended for the break-in because it was predicted that could rapidly clog the filter... that was not the case and now I wish I had installed the 3um from the start).
 
I've always found By-pass filtration fascinating.

However, being that I don't drive that much anymore and the initial cost of a bypass setup, I can't see a break even point for myself.
Either for decrease in wear, or longevity of the vehicle.

If I was doing cross country trips for business, where time was money, and pulling a oil sample to send off to a lab is cheaper than a Oil Change at the local lube joint in some unknown location.
Then I would absolutely go with a Bypass setup.

I have every reason to believe that tracking highway miles one could go 25,000-30,000 miles on a OCI with a large enough capacity system and a fine enough filter on today's premium synthetics.

However, for the average user of the American automobile the break-even point is so far out in the future I'm not sure it is worth it.

Hmm... makes me think about equiping a Mini Van with one. All that Soccer Mom style driving the extra capacity and cooling could really pay off.

Then again, it isn't the Engine that has an issue on a van, it's the transmission.
You would probably be better off adding the extra capacity, cooling, and filtration to the Transmission.
 
I did a search of SAE papers on the subject (I'm a long time SAE member) and I believe Jim Allen is right: the article was referencing a 1988 paper, and they didn't have any new info (Thanks, Jim).

There have been countless discussions on BITOG over increased engine life using a bypass filter, and there will likely be countless more. It's easy to get 300,000+ miles on an engine if it's well maintained and gets a good dose of highway miles without bypass filtration. For most people it's not worth the hassle and potential risks of installing the extra plumbing. But I know that all miles aren't equal: heavier loads, short trips, aggressive driving and lots of wear particles can l contribute to ring and bearing wear.

If you want to get 500,000+ miles on a car without incurring major repair expenses, what do you do? When my car was new I installed a Clear Bra over my front end & bumper, Wet Okole seat covers and custom floor mats along with my bypass filter and prelube pump. At 275,000 miles and 10.5 years on my S2000 my strategy is starting to pay off. My car still looks, handles and runs like new.

The Honda S2000 has an aluminum block and FRM cylinders. Reboring them isn't an option if they get worn. So if I can forego a major engine overhaul with a bypass filter, I'm thousands of dollars ahead. Some folks may not believe my filter makes a difference. That's fine - I didn't do this to convince anyone of anything. One thing is for certain: It's not doing any harm and I'm doing far fewer oil changes.
 
Originally Posted By: LeakySeals
At startup will there be a lag in flow as the pump strains to push oil a longer distance through smaller than standard filter media holes? Or is there a priming mechanism?


By-pass systems work with the full flow filter. That means the full flow filter still acts as per usual,the by-pass system takes only a small amount of oil from the sump,filters it,then re-introduces it to the engine via a hole tapped into a valve cover or some other place.
A by-pass system should nave no effect whatsoever on the actual oiling system of an engine ans shoud be independent of it.

Originally Posted By: slalom44
I did a search of SAE papers on the subject (I'm a long time SAE member) and I believe Jim Allen is right: the article was referencing a 1988 paper, and they didn't have any new info (Thanks, Jim).

There have been countless discussions on BITOG over increased engine life using a bypass filter, and there will likely be countless more. It's easy to get 300,000+ miles on an engine if it's well maintained and gets a good dose of highway miles without bypass filtration. For most people it's not worth the hassle and potential risks of installing the extra plumbing. But I know that all miles aren't equal: heavier loads, short trips, aggressive driving and lots of wear particles can l contribute to ring and bearing wear.

If you want to get 500,000+ miles on a car without incurring major repair expenses, what do you do? When my car was new I installed a Clear Bra over my front end & bumper, Wet Okole seat covers and custom floor mats along with my bypass filter and prelube pump. At 275,000 miles and 10.5 years on my S2000 my strategy is starting to pay off. My car still looks, handles and runs like new.

The Honda S2000 has an aluminum block and FRM cylinders. Reboring them isn't an option if they get worn. So if I can forego a major engine overhaul with a bypass filter, I'm thousands of dollars ahead. Some folks may not believe my filter makes a difference. That's fine - I didn't do this to convince anyone of anything. One thing is for certain: It's not doing any harm and I'm doing far fewer oil changes.


I love te idea of by-pass filtration. I've bought 2 franz kits. Consider cost of a top quality oil like red line or motul. Those oils cost 25 a quart here. So on a 6 quart sump thats 150 per oil change at 10000 miles. Now if I could stretch out an oci to 30000 miles then that save me 300 bucks,and that has now paid for the by-pass kit and I'm now seeing return on investment.
Once you consider cost and how many less oil changes you have to do you end up ahead.
And the by-pass system can come with you once the car is sold or totalled.
 
It is being said that bp filtration is more suitable on a diesel engine because of soot particles. I challenge that.

I have two cars, one is a prius with bypass, the other is a toyota aygo without bypass. Both are on lpg. If anything, the gaseous fuel should be producing almost no soot for the bypass filter to catch. Still, when I check the oil on the aygo, there is a black halo on the tissue paper that I use to clean the dipstick. On the prius, the tissue paper remains completely clean. This means that there are soot particles to be filtered, even when on lpg, so, their size is big enough to cause damage to surfaces.

Of course, the above doesn't tell how much damage is being avoided because of the bp filter, but I would assume that at least some amount is.

On the other hand, I really like the fact that I can avoid engine issues down the road, and on top of that, I live in europe, where (for some very odd reason) oil is very expensive and cheap oil is nowhere to be found. Add the high miles that both cars are doing and it can be understood why I am sad that I haven't installed a bp filter on the aygo as well.

I am a bp filtration believer.
 
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I will add a bit of my perspective into this. Jim and I have privately discussed this GM study before as well; SAE #881825.

There are several things I find objectionable to this study. The study itself is not flawed; the DOE was predicated on varying the filter efficiency and noting effects. And they do acknowledge the "correlation" in the title of the paper. But they only find causation when the "normal" environment is negated.

But where this really becomes flawed is in the laymans interpretation of the synopsis (non-members don't pay for the study, and so they can only glean a snip-it of info from the synopsis ...) and even if they did buy it, they don't often understand what they are reading.

You see, there are three things that contribute to controlling engine wear:
1) the oil add-pack
2) the filter efficiency
3) the OCI duration

GM predicated their study on the filter, so they had to exclude the other two contributors. Hence, they didn't use the OCI duration as a management tool to control the wear, nor did they account for the anti-wear layer. They GROSSLY dosed the system with fine dust, in a manner that would NEVER be seen to such magnitudes in real life. And then they looked at the wear via UOAs as a factor of filter efficiency ...

The oil add-pack is designed to help control contamiatinon, but it is predicated on an expected contaminante introduction rate (how much bad stuff goes in) and a purging rate (how often it is changed out). The oil add-pack detergents and dispersents are targeted to last for a given OCI. If you don't OCI, and then seriously overdose the contamination rate, can you really call this a test applicable to the real world?

No; that's just not applicable to the real world. And they even admit as such, buried in the study statements. Allow me to quote:
It is important to note that this analysis is used only to compare relative wear rates. Used oil analysis from engines in the field will not typically show such a clear correlation since wear metals generated between oil changes will be at much lower concentrations.
IOW - because they super-duper dosed the crankcase with dust WAY beyond what is "typical" over an entire engine's expected lifecycle, and NEVER OCI'd relative to that life expectancy, and totally ignored the anti-wear boundary topic, they had to make sure they stated that these results in UOA metals would NEVER be seen in the real world. In short, you'll not be able to duplicate this type of filtration induced lifecycle variance because of the way they manipulated the test! If you change oil as a "normal" person would, and use fresh lubes, you will flush out the contamination before it would ever get anywhere nearly as polluted as the crankcase in this study, and therefore you'd never experience wear rates this elevated. And when the wear rates are not elevated unique to each filter efficiency, the statistical variance is so muted that one cannot distinguish the difference between filters!

I love to make analogies; I'm nearly famous for it. So try this on for size ...
Consider the Kool-aid product. When used appropriately, it is a consumable product that is a blend of packet mix, sugar, and water. What would happen if we decided to "test" the product in a market survey, but we decided to ONLY test the packet mixture. We would not use the water, nor sugar; we were only going to taste test the "mix" packet. While we can track and study the results, it's not really applicable to the real world, is it? Would we not have to include both the water, and the sugar, in the prescribed mixture ratios, to make it a "fair" real world test? Also, to be really good, we'd not only have to use water and sugar, but we'd have to control those two ingredients in regard to quality and quantity, as prescribed by the intent of the OEM, would we not?

And so it goes with this GM filter study. They grossly contaminated the sump and didn't change oil relative to a prescribed interval, so as to negate the contributions of the lube in regard to wear control. Is that "real world" worthy?

Now, if you are in the habit of running without an air filter in place, and leave the oil-fill cap open to the enviornment, and plan to never, ever change your oil, then perhaps these results in the GM/SAE study might have a bearing on your filtration selection.

This study has absolutely zero influence on my filter choices because the data it develops is not applicable to the way I maintain my equipment. The "lifecycle extension" due to filtration variation in this study is not applicable to any BITOGers I know of, who tend to the complete anal-retentive opposit of the study parameters when it comes to lube and filter changes ...
 
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This may be off topic but...
in Unimogs with European specs (Euro III-V emissions, no EGR), OCI is specified as 1200 hrs with synthetic MB228.5 oil.
In N. American spec U500s with 228.3 oil (higher tier mineral 15W40s), OCI is specified as 700 hrs. Before 2004 without EGR, after that with EGR but also with a bypass centrifuge.
In other words, they feel the centrifuge does a good job of cleaning the
EGR-induced soot in the oil, and they also feel the synthetic oil is worth a 70% elongation of the OCI.
But of course as a typical BITOGer the longest I've run the oil is 600hrs - 21500mi. Some day when I drive from Alaska to Halifax/Europe to Mongolia and back to Europe I may get a chance to try a longer OCI; with higher sulfur fuel.
I placed my EGR in the garage.

Charlie
 
Originally Posted By: m37charlie
This may be off topic but...

In other words, they feel the centrifuge does a good job of cleaning the EGR-induced soot in the oil, and they also feel the synthetic oil is worth a 70% elongation of the OCI.



I would not disagree. In fact, I'd be in near total agreement.

Essentially, MB is putting faith in the fact that the bypass filters and syn fluids are tools to extend your OCIs.
 
Originally Posted By: dnewton3


I would not disagree. In fact, I'd be in near total agreement.

Essentially, MB is putting faith in the fact that the bypass filters and syn fluids are tools to extend your OCIs.


Do you have any valid info on the percentages by which various factors cause engine wear?
Perhaps that's a way to answer this debate once and for all, in a clear and concise way.


Thanks

PS: I still can't get my head around how the 1cm thick layer of dirt that forms at the bottom of my oil collection pan doesn't cause problems to my engines. Perhaps I should post some photos of it.
 
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Originally Posted By: alexeft
Originally Posted By: dnewton3


I would not disagree. In fact, I'd be in near total agreement.

Essentially, MB is putting faith in the fact that the bypass filters and syn fluids are tools to extend your OCIs.


Do you have any valid info on the percentages by which various factors cause engine wear?
Perhaps that's a way to answer this debate once and for all, in a clear and concise way.


Thanks

PS: I still can't get my head around how the 1cm thick layer of dirt that forms at the bottom of my oil collection pan doesn't cause problems to my engines. Perhaps I should post some photos of it.



We've recently been thru all that, so I suggest backtracking in this forum and reading some earlier posts which will answer many questions. But not the basic question...

As far as many of us can tell, and we have asked professionals in the field, no real-world study has been done that shows an improvement to X% filtration from a lower efficiency yields &% less wear. The fact is, nobody really knows how much less wear results from a 15um primary filter vs a 30 um in an engine used the way most people do and with normal contamination inputs. It stands to reason there are wear improvements with better filtration, but whether they are significant, or significant enough to warrant the extra expense necessary to achieve them is the big question. In other words, Return On Investment (ROI).
All we can say for sure is that the threshold is about 95-98% @ 40 um (do you guys agree with that generalization), above that, we can see some statistical increases in wear and below that the "wear curve" wear kinda levels off to an acceptable level.
 
First of all, thanks for the input.

I have read a lot on this forum, but as you said, the main question in my post has not been directly answered.
 
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