UOA vs Particle Counts- Comparison on Same Sample

[Jim Allen]

There has been some discussion on evaluating oil filter, or bypass filter performance on a regualr used oil analysis alone. Here is both the used oil analysis results and an optical particle count on the same sample of oil. Moderator: I posted this here because it seemed related to a discussion in this area, but if you gotta move it....

Anyway, look at how much more "junk" shows up on the PC than does on the used oil analysis, especially in that 6-14u area that causes most of the long term wear. This engine will be getting a bypass filter and we'll see how it does.

The used oil analysis
Neuss D358 diesel, 98 hours on R-T 15W40, Wix 51768 Filter (rated at 25u Nominal), 8251 hrs on engine.
Note: Metals are in MG/L not PPM!

Soot- 0.814
Oxidation- 21.9
Nitration- 10.3
TBN- 11.24
Fuel Dilution- 0.09
Visc- 15.72
Iron- 18
Chrome- 2
Lead- 1
Copper- 2
Aluminum- 3
Silicon- 1
Sodium-1
Potassium- 8
Boron- 28
Calcium- 2350
Zinc- 1272
Phosphorus- 971
Magnesium- 7
Sulphur- 3842

Particle Count
Note: Listed by size in counts/100mL

4-6u- 20,699,202/mL
6-14u- 2,869,403/mL
14-21u- 46,838/mL
21-38u- 1,695/mL
38-70u- 0
>70u- 0
ISO Code- 25/22/16

 

[Steve S]

The P.C. will show if the bypass is doing its job . I think there should be a difference. What kind of bypass filter are you going to run?

 

[Jim Allen]

Racor LFS. I tested it on my Ford diesel and it did a great job.

 

[Gary Allan]

Thanks for doing this, Jim. The PC is easy, integrating the elements is a task after seeing them in ppm. They appear to contour what one would expect. That is, either is good for evaluation if something is "un-right".

 

[dnewton3]

I generally agree.

I have reservations about the comments that Blackstone often makes about "filtration" when they connect the insolubles to filtration performance. It is not an infrequent occurence to see them state something such as "Insolubles were low showing your filter is working well" or something to that effect. I find no logic whatsoever in that statement.

What I DO find that makes sense is that filtration certainly has an affect on the oil contamination, but that below a certain level, it is the oil add-pack itself, rather than the filter, that helps control wear. It's not at all uncommon to see really nice wear numbers from "normal" lube systems. And often, the wear numbers do not significantly get "better" if you add a high end filter system over a short-to-moderate OCI duration. I've seen used oil analysis from guys with Dmax engines such as mine and they run synthetics with bypass, and yet their actual wear metals in a used oil analysis are no "better" than my standard lube system performance. That is because I keep my OCI short enough to flush out the contaminants before they get too large. I can "flush out" what they "filter out".

This post from Jim merely confirms (at least to me) that there really is no way to tell how much contamination is in your oil from a used oil analysis, nor is there any credible way to link a used oil analysis to filtration performance directly. However, there is an INDIRECT affect of contamination that we can view. Wear metals are the result of wear; most often caused by particles. If your wear metals are low, then one can presume SOMETHING is controlling the contamination.

So, we look for the constants and variables that affect wear.

Consider this scenario: two of the same engines, one uses conventional full flow filtration and one uses bypass. Both use the same oil. Run a series of 5k mile OCIs and used oil analysis. The wear metals will likely both come back very similar. The PC analysis will clearly show that the bypass filter is doing a "better" job of cleaning particulate from the oil. But the result (wear metals) is nearly identical. So, what is the "constant"? It's the OIL! Oil is what controls contamination. Until the contamination reaches a certain size, it's basically meaningless to the engine. So as long as you flush out the oil before it becomes overwhelmed, it's a moot point to "superfilter" it.

Bypass filtration can give fantastic results by helping the oil stay clean. It greatly prolongs the lifecycle of the oil. This is not a matter of making the equipment last longer; it's a matter of making the fluid last longer!

Now I will fully admit that bypass filtration may be able to provide a bit less measurable wear over some exaggerated life span, but to what level is it worth debating the nuances of the infintessimally small? Here's two examples:
http://www.autoblog.com/2008/02/01/wisconsin-mans-91-silverado-set-to-hit-1-million-miles/
http://www.knfilters.com/news/news.aspx?id=157
Two trucks with 1 million miles each on "normal" oil and lube filters simply changed frequently.
Could they have had "less wear" with bypass filtration? Perhaps - but just how much longer would you have to drive these trucks to find the ultimate failure point? Consider that this type mileage is extremely rare, but you can reasonably say that just about any vehicle should be able to make it 350k on "normal oil and filter" changes. Fact is, most people will never own/operate a piece of equipment this long; time, weather, boredom or wrecks will remove a vehicle from use long before a (properly maintained) engine will quit.

Now, these two Chevy Truck guys could have saved a lot of money by using synthetic fluids and bypass filtration, giving a fiscal savings and probably similar "wear" results. But again, who cares? 1 million miles and we would argue the topic of bearing clearances? What is evident is that the engine does NOT care, even if we do care.

PC analysis is very interesting, and gives a great view of the potential for damage. Unfortunately, it's a frame of reference for something that is easily mitigated by frequent oil changes.

 

[Jim Allen]

Yeah, Dave, that's pretty much how I see it too. Bypass filtration is more an OIL LIFE EXTENDER than an ENGINE LIFE EXTENDER. It's harder to justify for a non-commercial user but it does extend engine life.... perhaps only to provide a good used engine for someone after the body rots away from it and the owner dies of old age. Still, extending oil life can be a good thing and the bypass system can pay for itself that way. Commercial uses who put on a gazillion miles can realize more benefit and the numbers crunch much better because it saves some of the downtime necessary for service.

 

[Gary Allan]

I'd put it this way, even if you eliminated 50% of the unavoidable wear (that 90% of all wear that occurs at startup ala Castrol ..and SAE) ..making it a smaller curve in magnitude, the difference may only amount to an additional 25k on an ideal 450k life span of the engine.

..but we're also always defaulting on commercial/fleet/exceptional examples to prove these points. They tend to be the only data that extends far enough to bother with. I find it difficult to "reverse data" that down to our scale with anything other than "highly suggestive" confidence.

Does bypass filtration remove a significant amount of normal material decay random engine ejecta? Sure does. Does it filter smaller combustion byproducts ..absolutely.

Will that mean that your engine lasts longer in terms of MTBF? Unlikely. It will probably suffer some other non-lube related fatigue failure of a mechanical part and that will be deemed a mortal wound to the chassis ..if that's still viable at that point.

It may be in better condition when that event occurs.

 

[slalom44]

I agree with Dave that the primary benefit of the bypass is getting the oil to last longer, but I'm more biased toward believing that it results in a fairly significant amount of wear reduction. Admittedly, it is overkill and you might get the same life out of an engine without bypass but not under all driving conditions.

My used oil analysis with a bypass show significantly lower wear metals per mile compared to any used oil analysis per mile without a bypass. There is no real way to confirm that this translates in significant wear reduction (since some wear metals get filtered by the bypass)but my gut tells me less abrasive particles translates into less wear.

Have you ever tried to clean out an old bottle with a bunch of dirt inside? Fill it with water and shake it - virtually nothing happens. Fill it with water and sand and shake - it cleans it right up.

Rock polishing drums are neat too. Fill up the tumbler with rocks and an a series of water slurry mixtures and the dull rocks come out shiny. I have a hard time believing that contaminated engine oil would behave differently.

Almost every time someone has high wear metals and high silicon levels on a used oil analysis, the finger is pointed at air filtration. The opposite is also true: Reduce the hard abrasive silicon particles - especially the larger ones - and you will reduce wear caused by abrasion (not corrosion or oxidation).

 

[Gary Allan]

I don't think anyone will disagree with you. It's when you try and figure where that 90% of wear reduction pays off. 450k vs. 500k? ..or is it 500k vs. 550k? Nobody gets to track it out far enough to measure on a gas engine. Even if you eliminate the most of the unavoidable wear with block heaters and pan warmers ..which, as I said, makes a new curve of unavoidable wear, where will the pay off be in terms of "engine life". The basics of engine life are in the design ..engineering genetics..DNA. You'll manage to fall in some +/- standard deviation with the recommended care. Exceeding the recommended care may push you to the upper strata of the standard deviation ..but the variables at that point make other fatigue factors come into play.

I'd say that you'll have the cleanest and most healthy looking dead engine when a rod snaps (or some other non-lube related component just failing due to the manufacturing process variable regardless of how standardized it has become).

 

[dnewton3]

EXACTLY!


Several decades ago, I think bypass filtration had a much greater affect on ability to prolong the lifecycle of equipment.

Nowdays, the equipment design, the lubes, the relative quality of manufacture of all items is so good that bypass filtration adds precisous little (if any) lifecycle to equipment. Even if it does, it is WAY past the point where 99.99% of the people will benefit from it. As Gary says, you'll have the cleanest engine with the tighest tolerances that suffers from some other non-lube-related catastrophic event.

One might argue that the "cleaner, tighter" engine might run "better" and thereby have some type of fuel savings. But is the cost of that "savings" equaled or surpassed by the ROI of the bypass system? In other words, if you had a bypass system on your engine, and your neighbor did not, on his identical vehicle, would you save enough money from your "clean, tight" engine over his "normal" engine after 100k miles? Presuming you both OCI'd at similar "normal" intervals, there is no way to make it pay off. You won't save enough fuel from your super-extra-clean engine to pay for the initial cost of the BP system, and all it's higher maintenance costs if the OCIs are similar.

Today, the ONLY UNIQUE BENEFIT to bypass filtration is extended OCIs thereby making it fiscal savings tool.

 

[Doug Hillary]

Hi,
Jim - Thanks for the Thread. I studied the use of PCs along with the move to equipt my Series 60 Detroits with by-pass (Mann-Hummel centrifuge) filtration. For me it simply seemed to become an additional cost with few if any benefits

Over many many years I had been in the frontline with by-pass filtration in applications ranging from dozers, scrapers etc to reefer motors and - cars such as Simcas and some German diesels. Engines from all over the World

It became very clear to me that as the quality of lubricants improved (from the mid 1950s) and the need for supplementary oil capacity/cooling decreased the main purpose became simply to capture the major contaminants - namely iron and soot

I achieved this in turn by using a high quality synthetic HDEO that maintained viscosity at very long OCIs, and dispensing with the use of expensive FF filters, simply using cleanable 40micron SS cartridges along with the easily cleanable centrifuge instead

A by-product was reduced adjustment of the valve train on my vehicles

dnewton3 - You said this;
"Today, the ONLY UNIQUE BENEFIT to bypass filtration is extended OCIs thereby making it fiscal savings tool."

I fully agree and have often stated this on BITOG

 

[OneEyeJack]

I've always thought that by-pass filtration was to take care of the oil, not wear and tear on the engine. And I've always thought that a used oil analysis was done because it's cheaper than tearing down the engine to see the real wear and tear that is happening inside. And because of that the used oil analysis depends on how smart and careful the lab is with your sample, something you can't always control.

Has anyone tried to make a science of looking inside an engine with a boroscope and using computer aided video analysis? There is a lot that can be done with that kind of stuff and although it would not replace lab analysis it could give a different look at wear and maintenance problems. I've used a boroscope and high speed video capture with near infrared light frequency shifting to analyze gas flow in a running engine. With a little messing around we used it to tune valve springs and actually captured with a strobe light a valve train failure as it happened. With some more fiddling you can see patterns on cylinder walls and we have matched pattern observations with compression changes confirmed with a mechanical compression check. There may be something to be figured out from this kind of stuff that could supplement used oil analysis, computer diagnosis with physical observations and trouble shooting by humans. I just thing that a lot is put on oil analysis and the difference I've seen between labs and details in their methods and quality control is tough to qualify.