An oil test that shows ZDDPlus may not help - Richard C, please look

[Jerryl]

Well, now that everyone has had a chance to post their emotional reactions, maybe calm can prevail and science can proceed. I didn't post this to stir stuff up; anyone who knows me knows that I care about the science (and some would say little else, I've been accused of writing the longest and most boring posts on tb ). ................I assumed that there would be an initial wave of reactions but I really hope that we are now past that and that people will actually read those postings and think about the testing methodology and the science involved. It's not about popularity, it's about designing experiements and collecting data to confirm or refute hypotheses and doing it in a way that controls all the pertinent variables so that the experiments can be replicated and the data confirmed. If the speedtalk poster's methodology is flawed it will come out, if not, maybe current oils have additive packages that have changed composition so that they are no longer helped by additions of ZDDP and we need to know that. Or something else, but again, we need to know.

I have to agree and may need to go and read the article.
It will be interesting to hear Richard's side of the equation.

 

[we4Mateo]

I didn't think ZDDP was supposed to prevent metal to metal contact but rather work as a sacraficial layer between two metal parts so that itself gets scraped away instead of the metal on the parts you are trying to protect. So there really needs to be an analysis of the material getting scraped away rather than if scraping if occurring in the first place. I'm no scientist though.

 

[SGRIM]

Well, now that everyone has had a chance to post their emotional reactions, maybe calm can prevail and science can proceed. I didn't post this to stir stuff up; anyone who knows me knows that I care about the science (and some would say little else, I've been accused of writing the longest and most boring posts on tb ). I know that Richard and his people have done a lot of research on this, I have read his website end to end at least twice and talked with Richard about oils more than once. As a Buick owner and PhD chemist (but not a material scientist or tribologist) I have a healthy curiosity and some general knowledge about this subject, and since these results seemed to me to have been obtained in a careful systematic way that I couldn't easily refute, and since they show such a surprising drop in film strength when extra ZDDP is added to the current SN oils I wanted to make sure Richard and others saw the post and had a chance to think about it and respond to the science. I have read the postings on speedtalk, where the methodology is presented, and I think it needs to be taken seriously. First, this is not that silly hand crank snake oil seller, this is a machine used in an ASTM test that applies the load slowly and systematically to a wear surface that is carefully prepared fresh for each test. The ASTM procedure was followed at first and many repetitions performed until the poster was convinced that he could reproducibly generate accurate results. He then tested many oils, performing several repetitions in each case to improve his accuracy, and repeated tests of oils over time to make sure that no systematic drift was ocurring. He did decide to use a higher oil temperature than the test specifies, to better represent an operating engine and not a cold start in his opinion. This did not change his relative rankings of about 30 different oils that he tested both ways but it does open him to the criticism of "making up his own test". He is not selling anything and doesn't work for any oil company, he just wanted to know for himself. Here are links to his earlier test reports: viewtopic.php?f=1&t=30483, viewtopic.php?f=1&t=30596, and http://speedtalk.com/forum/viewtopic.php?f=1&t=31406 (hope this come through ok). As part of the discussion in those posts I and a couple of others asked about testing ZDDPlus or another additive to see what effect it had, and the link I posted first is the result of that test.

I assumed that there would be an initial wave of reactions but I really hope that we are now past that and that people will actually read those postings and think about the testing methodology and the science involved. It's not about popularity, it's about designing experiements and collecting data to confirm or refute hypotheses and doing it in a way that controls all the pertinent variables so that the experiments can be replicated and the data confirmed. If the speedtalk poster's methodology is flawed it will come out, if not, maybe current oils have additive packages that have changed composition so that they are no longer helped by additions of ZDDP and we need to know that. Or something else, but again, we need to know.

I wasn't talking to you, btw

 

[Dennis Kirban]

I figured I would chirp in as the largest seller of zddplus for Richard Clark. Just a few points of interest. A year or so back Richard Clark was able to get hold of a quart of oil from a new Corvette that was getting its first oil change. The amount of zddp in that oil was around 3,000 ppm....so with that in mind it would certainily appear that GM was taking every precaution that wear issues would not happen in new Corvette engines.

Think back when your turbo Buick was new in 1986-1987 oil had 1800 ppm of zddp. Richard has made it simple for owners of flat tappet cam performance engines to bring back the zddp levels that was in the oil back in 1987 which was 1600-1800 ppm under the SF category. (Check your visor decal).

I count three cam companies as our customers for the product, Erson, Isy, and Crower. All cam companies you have heard of. They would not be buying this product from us unless there was a need for it for their performance cams. Even Comp Cam now has its own brand of special formulated oil with more zddp in it.

denniskirban@yahoo.com

Remember wear issues can happen over a period of time.

 

[QwuickTurbo6]

Well, now that everyone has had a chance to post their emotional reactions, maybe calm can prevail and science can proceed. I didn't post this to stir stuff up; anyone who knows me knows that I care about the science (and some would say little else, I've been accused of writing the longest and most boring posts on tb ). I know that Richard and his people have done a lot of research on this, I have read his website end to end at least twice and talked with Richard about oils more than once. As a Buick owner and PhD chemist (but not a material scientist or tribologist) I have a healthy curiosity and some general knowledge about this subject, and since these results seemed to me to have been obtained in a careful systematic way that I couldn't easily refute, and since they show such a surprising drop in film strength when extra ZDDP is added to the current SN oils I wanted to make sure Richard and others saw the post and had a chance to think about it and respond to the science. I have read the postings on speedtalk, where the methodology is presented, and I think it needs to be taken seriously. First, this is not that silly hand crank snake oil seller, this is a machine used in an ASTM test that applies the load slowly and systematically to a wear surface that is carefully prepared fresh for each test. The ASTM procedure was followed at first and many repetitions performed until the poster was convinced that he could reproducibly generate accurate results. He then tested many oils, performing several repetitions in each case to improve his accuracy, and repeated tests of oils over time to make sure that no systematic drift was ocurring. He did decide to use a higher oil temperature than the test specifies, to better represent an operating engine and not a cold start in his opinion. This did not change his relative rankings of about 30 different oils that he tested both ways but it does open him to the criticism of "making up his own test". He is not selling anything and doesn't work for any oil company, he just wanted to know for himself. Here are links to his earlier test reports: viewtopic.php?f=1&t=30483, viewtopic.php?f=1&t=30596, and http://speedtalk.com/forum/viewtopic.php?f=1&t=31406 (hope this come through ok). As part of the discussion in those posts I and a couple of others asked about testing ZDDPlus or another additive to see what effect it had, and the link I posted first is the result of that test.

I assumed that there would be an initial wave of reactions but I really hope that we are now past that and that people will actually read those postings and think about the testing methodology and the science involved. It's not about popularity, it's about designing experiements and collecting data to confirm or refute hypotheses and doing it in a way that controls all the pertinent variables so that the experiments can be replicated and the data confirmed. If the speedtalk poster's methodology is flawed it will come out, if not, maybe current oils have additive packages that have changed composition so that they are no longer helped by additions of ZDDP and we need to know that. Or something else, but again, we need to know.

I have yet to read the speedtalk discussion but I can already see what I think are some misconceptions from your post. It sounds as if the test does not address the attributes of ZDDP. ZDDP is a multifunctional lubricant. One of its roles is an absorbent. The adsorption of ZDDP on Fe, Iron oxides, steel, etc have been well documented. One benefit to this is when the motor does a cold start. A film remains on the high wear surfaces we are concerned with, and when the motor is initially turned over and started, the ZDDP film protects those parts. Newer oils and especially synthetic oils do not have this absorbent behavior without ZDDP. I'm also interested what ZDDP species were tested and what solutions were utilized as the solvent determines the stability of the ZDDP solution. How pure was the ZDDP (it can and will react with contaminants)? It takes time for absorption to take place. Was this taken into account? Lab tests use a centrifuge spinning 3000-5000 rpm for extended periods (sounds like a combustion engine right?) of time. There sounds like so many variables, I would be careful drawing any conclusions yet.

 

[ijames]

QuickTurbo6, please read the threads on speedtalk and you will see how the tests were performed and what oils and mixtures he tested.

 

[ravege]

Over on www.speedtalk.com one poster has been doing a lot of oil testing using a machine that measures the film strength of oils - in other words how much pressure a film can stand before allowing metal-to-metal contact. You can search for his previous 3 or 4 threads to see his procedure and earlier results, but in the latest he added Zddplus and the Edelbrock Zinc Additive to three different oils he had already tested, and in all cases the additive lowered the film strength by 20-40%! Here's the link: http://speedtalk.com/forum/viewtopic.php?f=1&t=31791&p=378842#p378842 Sure makes me go "hmmm". Richard, I know you did a lot of testing while developing ZDDPlus; what do you think of his method and results?

I read the post and I found the analysis incomplete, at best. If the poster's intent is to show adding zinc and phosphorous is a bad thing, why does the additive which adds less perform worse? The "best" oil according to his tests have very high levels of zinc and phosphorous. The author makes no effort to explain this. Clearly the amount of zinc and phosphorous has no measurable affect in his test - that pretty much invalidates it right there. However, if we were to take the results at face value, I would point to the liquid holding the compounds in suspension (small words: the goo holding the zinc and phosphorous, I trust no one thinks the additives are pure liquid zinc and phosphorous, kinda hard to do at room temperature ).

 

[QwuickTurbo6]

QuickTurbo6, please read the threads on speedtalk and you will see how the tests were performed and what oils and mixtures he tested.

I read it. It's a poorly designed experiment made by someone with no background in chemistry and no knowledge of ZDDP. The film layer actually has to be penetrated in order for the reaction between zddp and the metal to begin. I have the reaction mechanism but it is rather complex. Here's a quote from one actual scientific study:
"Zinc dialkyldithiophosphates operate mainly as antiwear agents but exhibit mild
extreme-pressure characteristics. As an antiwear agent, ZDDP operates under mixed
lubrication conditions with a thin oil film separating the metal parts. Surface aspe-
rities, however, intermittently penetrate the liquid film, giving rise to metal-on-metal
contact. The ZDDP reacts with these asperities to reduce this contact. Likewise,
when the load is high enough that the oil film collapses, the ZDDP reacts with the
entire metal surface to prevent welding and reduce wear. A great deal of study has
been done to determine the nature of this protective film and the mechanism of
deposition, where the thermal degradation products of the ZDDP are the active anti-
wear agents.
The antiwear film thickness and composition are directly related to tempera-
ture and the extent of surface rubbing. Initially, ZDDP is reversibly absorbed onto
the metal surface at low temperatures. As the temperature increases, catalytic decom-
position of ZDDP to dialkyldithiophosphoryl disulfide occurs, with the disulfide
absorbed onto the metal surface. From here, the thermal degradation products (as
described in Section 3) are formed with increasing temperature and pressure until
a film is formed on the surface [16]. The thickness and composition of this film have
been studied using many different analytical techniques, but no one analysis gives a
concise description of the film size and composition for the various kinds of metal-
to-metal contact found in industrial and automotive lubrication regimes. In general,
the antiwear/extreme-pressure ZDDP film can be said to be composed of various
layers of ZDDP degradation products. Some of these degradation products are
reacted with the metal making up the lubricated surface. The composition of the
layers is temperature-dependent" (R McDonald, 2003)

 

[ijames]

Thank, qt6. In his tester the force pressing two metal surfaces together is steadily increased with one surface stationary and the other spinning. At some force the oil film is penetrated and metal to metal contact starts, which should cause the zddp to begin to decompose and adhere to the surface and go through the chemical cascade described above and thus provide protection as the force is increased further. I don't know if the test ends at a particular force or a particular drag on the spinning surface, but after the test is stopped the size of the wear scar is measured to give the film strength measurement. I don't see anything in the text you quoted above that makes this test invalid as a measure of film strength - it is basically the ASTM procedure to meausure exactly that, and there is plenty of metal to metal contact as the test proceeds. I also don't see anything about the test that would explain why he should get different results when he adds ZDDP compared to when it is already in the oil from the manufacturer, assuming thorough mixing which I'm willing to take on faith given the care he has taken elsewhere.

ravage, the tester's intent was to see if he could measure the film strength of various oils to see which ones provide better surface protection once metal to metal contact has begun, like when a lifter begins to scuff on a cam lobe. After testing 30+ oils he found that there was no direct correlation between the zinc and phosphorus elemental composition, and the measured film strength. He does not have any way to measure the various chemical forms of zinc (portion that is zddp, portion that is some other antiwear compound, portion that could actually be zinc dust ), so it's true that he has to assume that all the zinc is present in antiwear compounds. One of his conclusions based on this lack of correlation is that as oils have progressed from the SF spec to SN, yes the zinc levels have dropped but apparently the oil manufacturers have substituted other, non-zinc containing additives to increase the film strength to make up for the lack of zddp. Each brand has its own package but you can't predict the film strength just by looking at the zinc level - there were good oils with high zinc and bad oils with high zinc, etc. It's apparently the overall package that matters, not just the zinc level. After this examination of a lot of different oils as sold, he picked three and added zddplus (and separately, edelbrock zinc additive) to them and tested the mixture. Based on the fact that the level of ZDDP required for initial protection is actually not that high, and adding more generally does not provide very much more "acute" protection immediately but simply keeps the protection level up for more miles as the ZDDP is slowly used up, my expectation was that the measured film strengths would be about the same as without the additive. The big surprise is that he saw a 20-30+% drop in film strength.

Thank you both for thinking about this and posting.

 

[QwuickTurbo6]

Thank, qt6. In his tester the force pressing two metal surfaces together is steadily increased with one surface stationary and the other spinning. At some force the oil film is penetrated and metal to metal contact starts, which should cause the zddp to begin to decompose and adhere to the surface and go through the chemical cascade described above and thus provide protection as the force is increased further. I don't know if the test ends at a particular force or a particular drag on the spinning surface, but after the test is stopped the size of the wear scar is measured to give the film strength measurement. I don't see anything in the text you quoted above that makes this test invalid as a measure of film strength - it is basically the ASTM procedure to meausure exactly that, and there is plenty of metal to metal contact as the test proceeds. I also don't see anything about the test that would explain why he should get different results when he adds ZDDP compared to when it is already in the oil from the manufacturer, assuming thorough mixing which I'm willing to take on faith given the care he has taken elsewhere.

ravage, the tester's intent was to see if he could measure the film strength of various oils to see which ones provide better surface protection once metal to metal contact has begun, like when a lifter begins to scuff on a cam lobe. After testing 30+ oils he found that there was no direct correlation between the zinc and phosphorus elemental composition, and the measured film strength. He does not have any way to measure the various chemical forms of zinc (portion that is zddp, portion that is some other antiwear compound, portion that could actually be zinc dust ), so it's true that he has to assume that all the zinc is present in antiwear compounds. One of his conclusions based on this lack of correlation is that as oils have progressed from the SF spec to SN, yes the zinc levels have dropped but apparently the oil manufacturers have substituted other, non-zinc containing additives to increase the film strength to make up for the lack of zddp. Each brand has its own package but you can't predict the film strength just by looking at the zinc level - there were good oils with high zinc and bad oils with high zinc, etc. It's apparently the overall package that matters, not just the zinc level. After this examination of a lot of different oils as sold, he picked three and added zddplus (and separately, edelbrock zinc additive) to them and tested the mixture. Based on the fact that the level of ZDDP required for initial protection is actually not that high, and adding more generally does not provide very much more "acute" protection immediately but simply keeps the protection level up for more miles as the ZDDP is slowly used up, my expectation was that the measured film strengths would be about the same as without the additive. The big surprise is that he saw a 20-30+% drop in film strength.

Thank you both for thinking about this and posting.

How do you explain published studies from groups of phd's that all disagree with the weekend warrior here that is now the authority on chemistry, lubricants, and thermodynamics? I'd also like to add there are other benefits to ZDDP. It has other roles (antioxidant etc)

 

[ravege]

ravage, the tester's intent was to see if he could measure the film strength of various oils to see which ones provide better surface protection once metal to metal contact has begun, like when a lifter begins to scuff on a cam lobe. After testing 30+ oils he found that there was no direct correlation between the zinc and phosphorus elemental composition, and the measured film strength. He does not have any way to measure the various chemical forms of zinc (portion that is zddp, portion that is some other antiwear compound, portion that could actually be zinc dust ), so it's true that he has to assume that all the zinc is present in antiwear compounds. One of his conclusions based on this lack of correlation is that as oils have progressed from the SF spec to SN, yes the zinc levels have dropped but apparently the oil manufacturers have substituted other, non-zinc containing additives to increase the film strength to make up for the lack of zddp. Each brand has its own package but you can't predict the film strength just by looking at the zinc level - there were good oils with high zinc and bad oils with high zinc, etc. It's apparently the overall package that matters, not just the zinc level. After this examination of a lot of different oils as sold, he picked three and added zddplus (and separately, edelbrock zinc additive) to them and tested the mixture. Based on the fact that the level of ZDDP required for initial protection is actually not that high, and adding more generally does not provide very much more "acute" protection immediately but simply keeps the protection level up for more miles as the ZDDP is slowly used up, my expectation was that the measured film strengths would be about the same as without the additive. The big surprise is that he saw a 20-30+% drop in film strength.

Thank you both for thinking about this and posting.

If I've understood the situation correctly, there was a point in time in which numerous older vehicles were suffering wiped cams. This was correlated to a change in oil formulation. If that is true, then the statements that modern oils have less zinc, but its effects are made up for with "other stuff" doesn't hold up. It also calls into question, why are car manufacturers using a high zinc break in oil? Zinc doesn't matter anymore, that is what you (or the guy on the other board) are saying, right? Both manufacturers and end users don't agree and are seeing adverse effects of zinc (or no zinc). If the test cannot detect the effects zinc, it is not recreating real world conditions, because while his test can't detect a difference, older cars apparently can. Instead, the claim is made the test is good recreation of an engine environment - which requires the conclusion that "other stuff" in new oils is making up for zinc. What is "other stuff", btw? Since its the linchpin of that post, it's kind of important.

 

[lazaris]

I have not seen a post that here that talks about what anti wear agent that has been added to most oils starting in about 2003 with the reduction of zinc. There are some pretty smart chemical engineers that work for the oil companies. I dont believe they would just reduce the zinc content knowing that wear could increase with out supplementing another anti wear/EP chemical into its oil package. By the way Boron is chemical agent........

 

[we4Mateo]

I have not seen a post that here that talks about what anti wear agent that has been added to most oils starting in about 2003 with the reduction of zinc. There are some pretty smart chemical engineers that work for the oil companies. I dont believe they would just reduce the zinc content knowing that wear could increase with out supplementing another anti wear/EP chemical into its oil package. By the way Boron is chemical agent........

I'm pretty sure they just keep hardening surfaces in the engine so that the Zinc isn't needed. Detergent and base oil properties have been munipulated a lot and are better, but I don't think a new substance or compound is at work; just reduced need for it.

 

[lazaris]

I'm pretty sure they just keep hardening surfaces in the engine so that the Zinc isn't needed. Detergent and base oil properties have been munipulated a lot and are better, but I don't think a new substance or compound is at work; just reduced need for it.

If you are referring to Boron that is incorrect.

 

[TurboTnZ06]

I read the article, the tester clearly states he uses the same snake oil machine in his tests, but uses it more slowly. Applying weight slower or faster doesn't change the ability of the machine to find wear any differently over time compared to the snake oil demos. In order to prove his test results as accurate, the testing machine needs to be proven to work accurately. I didn't see that part in the article? You shouldn't get the nobel prize by publishing a paper, your results have to be validated by your peers. I run Zddp and even have a spare case of Brad Penn oil because I read all the research years ago to reach my conclusions from multiple sources. The results from the test posted by the OP does not align with the other test data I've read about.

 

[ijames]

If I've understood the situation correctly, there was a point in time in which numerous older vehicles were suffering wiped cams. This was correlated to a change in oil formulation. If that is true, then the statements that modern oils have less zinc, but its effects are made up for with "other stuff" doesn't hold up. It also calls into question, why are car manufacturers using a high zinc break in oil? Zinc doesn't matter anymore, that is what you (or the guy on the other board) are saying, right? Both manufacturers and end users don't agree and are seeing adverse effects of zinc (or no zinc). If the test cannot detect the effects zinc, it is not recreating real world conditions, because while his test can't detect a difference, older cars apparently can. Instead, the claim is made the test is good recreation of an engine environment - which requires the conclusion that "other stuff" in new oils is making up for zinc. What is "other stuff", btw? Since its the linchpin of that post, it's kind of important.

I especially agree with the last sentence. The tester isn't saying zinc doesn't matter, he is basically claiming that there are other additives in use now that can make it less necessary. I do want to point out that there have been several generations of oil formulation since our cars came out (SF in 87 up to I believe SN now), so to me it is entirely possible that current oils may not need zddp added. That is the crux of the matter to me - have we gotten past the need for it, or does it still serve a purpost to add it?

 

[ijames]

I read the article, the tester clearly states he uses the same snake oil machine in his tests, but uses it more slowly. Applying weight slower or faster doesn't change the ability of the machine to find wear any differently over time compared to the snake oil demos. In order to prove his test results as accurate, the testing machine needs to be proven to work accurately. I didn't see that part in the article? You shouldn't get the nobel prize by publishing a paper, your results have to be validated by your peers. I run Zddp and even have a spare case of Brad Penn oil because I read all the research years ago to reach my conclusions from multiple sources. The results from the test posted by the OP does not align with the other test data I've read about.

Do you have any pictures or link to pics of the machine? That is one thing the tester never responded with; not even a manufacturer or part number of his machine. He just made some comments on how the rate at which the load was applied could affect the results and that that was how salesmen would rig the results when they were comparing their oil product to a competitors while doing a demo. I've never seen one of these in person so I don't know the differences between ones a salesman might use and whatever one the tester is using. As far as a Nobel just for publishing, you are dead right, the essence of science is to publish so your work can be replicated, validated, and expanded upon by others. I know it sounds like I'm defending the tester's work but my intent is to try to answer questions with info he has posted since I know that not everyone here has read all of his postings.

As far as explaining why his results differ from "groups of phd's", well, that's why I posted this in the first place . I wanted to see if anyone could point out specific errors in his method or conclusions and explain what the error was.

 

[A2000RICH]

Re: Speedtalk posting: “Does ‘ADDING” Zinc to low zinc oils really help?

In a July 12th posting by “540 Rat” he claims to have performed testing which in his mind “proves” that ZDDP is not needed in amounts greater than the ~600ppm amount as measured by the phosphorus level found in modern oil.

We applaud the can-do spirit behind his “testing” and indeed he employs certain testing methods which show a greater than average knowledge of testing procedures and a grasp of the principles of testing repeatability. However, this merely means his tests are repeatably invalid.

We do not know what function this SAE member has in his job, but he has used the incorrect test to quantify his ZDDP hypothesis. The Timken tester has only ever been suggested for use in these procedures:
ASTM D2509 - 03(2008) Standard Test Method for Measurement of Load-Carrying Capacity of Lubricating Grease
ASTM D2782 - 02(2008) Standard Test Method for Measurement of Extreme-Pressure Properties of Lubricating Fluids (Timken Method)

Of the two, only D2782 is relevant to liquid lubricants, namely gear oils, and it was designed to test for the presence of EP additives, not quantify the amount or performance of them. The Timken machine commonly known as the “one-armed bandit” indeed makes for entertaining demonstrations, but the experts in lubrication have dismissed the applicability of its results to its initial intended application as well as other bearing systems. It was never intended to quantify performance of motor oils.

To quote experts that certainly know more about the subject than either ZPlus or Mr. 540 Rat:

"The 4-ball test (ASTM D4172) is often used as a screening test for many different lubricant types that contain antiwear additives or similar base oil properties. Other tribo-mechanical bench tests are often used as well, including the Timken Test (ASTM D2782) and the Pin and V-Block (ASTM D2670). Because engines have different contact geometry, loads, metallurgy and speeds, numerous bench tests and test protocols are needed. It is not uncommon for several oils to be tested using two such methods and to find that the performance rankings between the oils to reverse (no correlation). This is why, among other reasons, Passenger Car Motor Oils and Heavy Duty Oils (diesel crankcase) are tested in actual engines using controlled methods such as ASTM D5533 Sequence IIIE and D5302 Sequence VE.
Jim Fitch, Noria Corporation"

and

In their paper, "The Timken Lubricant Test - 1932 to 1972", presented at the 40th annual meeting of the National Lubricating Grease Institute, D.V. Culp and J.E. Leiser of the Timken company reviewed the application and significance of the OK Load Test with EP lubricants.

Two items discussed in the paper are of particular interest. The hypothesis that gear oils which have higher Timken OK values will provide better scoring protection for gears and bearings was developed in the early 1930's. Recent developments in the chemical aspects of EP additives indicate that this is no longer true. In fact, it now appears that many of the more modern type chemical additives, particularly those successfully being used in the MIL-L-2105B type oils, have shown improved performance in preventing scoring in high temperature gear and bearing applications although they show a very decreased Timken load as compared to the leaded type or SCL type gear oils.

The authors also point out the lack of a direct across-the-board correlation between high Timken EP values and increased performance characteristics. It also appears that there is little correlation between Timken test results and other EP tests results, such as the Falex, the four-Ball tester and the more recently used FZG gear type tester.

The significance of the observations made by the Timken Company concerning the limitations of the OK Load test in predicting actual performance of EP oils should be recognized when making a product recommendation. A proven record of satisfactory performance in similar applications is of greater importance in recommending a product than merely selecting one whose Timken OK Load Test rating meets the specification.
Documentation of actual successful performance of EP oils is still the most valid way to support the claim that an oil will provide the required protection of gears and bearings.

According to the Society of Tribologists and Lubrication Engineers, the Timken test is "questionable for use in evaluating levels of EP".

Mr. 540 Rat proclaims: “…By testing in this manner, it absolutely shows which oils are better at preventing wear than others. This is NOT Rocket Science. But, it is a real world test comparison.” Indeed, it is certainly and without question a real-world test of what liquids perform best…on a Timken tester. Unfortunately by this comparison, Clorox and Coca-Cola have historically proven to be fantastic lubricants in that test, as are certain soaps. The point being that performance on this tester does not correlate with performance inside an internal combustion engine. Period. Don’t take our word for it; after all, a cynic would say we are ONLY interested in selling boat-loads of ZDDPlus™. Don’t take Mr. 540 Rat’s word for it; take the word of Jim Fitch of Noria, one of the leading tribologists and lubrication specialists in the world, or the word of two engineers who worked for none other than the Timken bearing company ( well known for ball and roller bearings) which designed the Timken machine itself.

After 40 years of touting the Timken machine the Timken company had to do a retake and ceased manufacturing the “one armed bandit” due to the inconclusive results it obtained. The Falex company took over making the machine in 1982.

Why is the one-armed bandit not a valid test to predict oil performance in a cam-lifter interface? There are many reasons including the entrained oil film effect which occurs in a constantly moving contact patch. The one-armed bandit holds a pin at a constant point on a rotating cylinder. The very design of a flat-tappet system assumes deformation of the metal along a rotating contact patch, which spreads the pressure over a large area and entrains lubricant. Tribologists specializing in internal combustion valve trains know that the minimum amount of ZDDP needed is predicated by oil viscosity, valve spring pressure, rocker ratio, relative moving member velocity, offset from cam centerline to lifter centerline, axial cam face angle, temperature, contact pressure and cam geometry.

The ZDDP antiwear measurements which have been done have utilized internal combustion engines of relatively low performance. These tests arrive at a 600-1000ppm level of ZDDP as measured by phosphorus content. This is EXACTLY why the API standards derived from these elaborate and EXPENSIVE tests like ASTM D5533 Sequence IIIE and D5302 Sequence VE stipulate NO LESS than 600ppm for a passenger vehicle engine. There is no simple way to quantify a specific engine’s ZDDP requirement; engine testing is the only way as has been verified by the ASTM and API. If any one has enough cash, South West Research (210-522-2305) will be glad to provide documented performance for a few hundred thousand dollars per run. Barring that, actual in-use tests are the only way. At Zplus we have spent a small fortune with South West Research over the years on testing numerous oil samples. They are one of the largest API certified testing labs in the USA and if the simple one armed bandit would tell us anything meaningful about motor oils you can bet the industry would be using it for that purpose.

Anyone researching the issue even casually will learn that ZPlus, LLC did not invent ZDDP, it has been essential in oils for 70 years, and is still formulated into virtually every internal combustion engine oil made. And since we have skin in this matter as well, let’s be perfectly clear on this issue; the reason we first made ZDDPlus was due to the increased rate of cam failures we saw in our Turbo Buick performance cars when the new lower ZDDP oils were phased in. These are not regular passenger vehicles, they are performance cars. We do not force any one to buy ZDDPlus™, we make it available to them for use in their classic and performance car, and it is not intended for a modern passenger car. We only recommend dosing to a level equivalent to the oil current and recommended at the time of the engine’s manufacture, so compatibility with that level of ZDDP is designed into that engine. Read that last sentence again carefully: it is the crux of the issue!

(Continued on the next post)

 

[A2000RICH]

(continued) Re: Speedtalk posting: “Does ‘ADDING” Zinc to low zinc oils really help?

If Mr. 540 Rat is comfortable using modern low ZDDP oil in his (we assume) Chevy big block, then there is no one arguing with him, and seriously we wish him well in that effort. We do however, take exception to him or any one repeating a fatally flawed series of tests using inappropriate equipment and procedures and then spreading them as gospel, pointing to our product (along with others) as potentially increasing wear. His ignorance and resulting misinformation can only hurt other enthusiast’s hard won efforts at building high performance engines and preserving classic cars. We find that disturbing as well.

Everyone owes it to themselves to act only upon information that they can verify is reliable. It is interesting that just about every oil manufacturer, major and boutique, now formulates high-ZDDP oil for higher-performance and classic cars, and this started when the ZDDP level in modern oils was lowered. Ask any Nascar engine builder or your local drag-racing engine builder if ZDDP level is important. They do not merely sit around and speculate about wear factors; we know this since we have been working with many of them to help alleviate the problem. They have been some of the most vocal opponents of the lowering of ZDDP, since their application is severe and shows the limitations of low-ZDDP oil. Their bottom-line: it costs them time and money to lose races due to engine failures.

The information in this discussion has been available to the automotive enthusiast community for decades, yet people continue to be swayed by the results of this machine. What is it about the one-armed bandit that makes it so compelling that people are drawn in time and time again? Perhaps it’s the image of the spindle coming to a smoking stop with all the challenger’s oils, while the oil from our sponsor allows a seemingly infinite load on the handle? People love a winner and this machine can make a smoking loser out of one oil and a peerless winner out of another. Who doesn’t remember the TV ad where an additive (with chlorinated paraffins) is proven superior to all commonly available motor oils with a one armed bandit and then 4 time Indy winner Al Unser validates the test by draining the oil from a new Viper and driving it in circles in the desert. This is the level that Rat 540 has lowered himself with this article. It seems so clear-cut and obvious when you see it…too bad the results don’t correlate to the use of the oil in an engine, no matter how carefully you use it.

A visit to the Zplus website and skimming the dozen or so tech briefs will tell most any novice all they would ever want to know about engine oil. And if you want to get your PhD in motor oil we suggest going to the ASTM website and paying for and downloading the 1087 page “Fuels and lubricants Handbook”

 

[SGRIM]

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