ZDDP, API, and ILSAC

[Towel_Rail]

Originally Posted By: Jaybird
The motorcycle crowd has their unfounded moly scares, and the block engine guys have their unfounded zinc scares. The moto guys think that any moly content will hose up their clutch system, which is an unfounded assumption.


Busting out the ad hominems. I'm scared now.

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The fact is that ZDDP content is not the way to judge the integrity of an oil. Studies have proven that there are many types of chemicals and compounds that interact quite well with ZDDP, and tend to improve or enhance the protective film that ZDDP offers. Some of the car guys caught onto the fact that when ZDDP levels seem to be lowering, there seemed to also be a rise in boron content. So immediately the car guys seem to think that if there is a drop in ZDDP, then there must be an accompanying rise in Borate level.

But what the car guys fail to realize, or have not researched, is that there are other products that are already being used that can enhance, or even replace the ZDDP content of an oil, yet still provide the same or better protection.
Many of these items not detectable with normal elemental analysis.


The chief reason for using ZDDP as a yardstick is because it is a known quantity and is easily detected. It's pretty well established that if the concentration is at a certain point, it will adequately protect a pushrod valvetrain. Even if a certain oil has ashless AW agents that are undetectable, how do we know they are in a high enough concentration for pushrod engines?

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I have yet to see any SAE papers referenced that explain that we need ZDDP, per se, and I am full aware of it's worth. Although I have seen lots of data that suggests there are many different things that are showing to interact very well with ZDDP. And these synergistic reactions between zinc and other elements or compounds are what allows the formulator to provide a quality fluid that is not dependent on any particular level of ZDDP as a benchmark. In fact, if you give a look at the info JAG provided, you will see that oil can be formulated with no zinc at all, and perform on par with a high zinc content fluid.


I read the Crompton paper too. Looks like everything except for imidazolidine thione and phenolic borate suck without some level of ZDDP present to help them.

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• What vehicles and engines were in the fleet of 1991 cars in the paper you cite as evidence that ZDDP isn't required?

I believe it was taxi cabs, but it is irrelevant.


It makes all the difference in the world. If the taxi engines used roller lifters or overhead cams, then they can run on pretty much anything.

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What sort of study can we read determining that there needs to be a high rate of ZDDP?
Studies such as this one tend to show this not to be the case:
https://shop.sae.org/technical/papers/952344
I gather from this paper that the benefit of higher ZDDP was attributed to the fact that higher rates increased the oils ability to withstand oxidative thickening, and not with it's prowess as an AW film.
I only refed. that paper because they found that there was not significant difference in performance between higher dosed oil and lower ZDDP oil. They concluded the higher ZDDP level helped with oxidative thickening more than anything. Which makes sense, as formulators take advantage of the great job ZDDP does in fighting acidity.


Once again, no mention is made of the valvetrain design in the above study, which seemed primarily focused on cat life anyway.


I'd like to think that I've got an open mind, and that the newer oils are better for everything, but that remains to be proven, IMO. UOAs and engine teardowns will ultimately determine if the new low-SAPS oils (designed for OHC engines) are up to snuff.

- Scott

 

[NovaMan]

Jaybird, so far the most compelling evidence that there are other additives which can perform as well as ZDDPs is the Crompton presentation. My notes on that:

• 0.1% ZDDP was more effective that 0.05% ZDDP.
• It looked to me like ZDDP improved the performance of the Zn-free adds, not the other way around. But that's a matter of opinion, which you hate if it doesn't coincide with your own.
• The Zn-free additives were used in concentrations 10x that of ZDDP.
• Crompton is an additive company trying to sell Zn-free additives. That means they're marketeers!

Although not generally regarded to be quite as rigorous as journals like the Journal of Tribology, Tribology Letters, Tribology Transactions, etc., here's an article in Science:
http://www.sciencemag.org/cgi/content/full/307/5715/1612?ijkey=a3yAz9pObql0I&keytype=ref&siteid=sci
It's an interesting read (unless you passionately hate ZDDPs) about how ZDDPs work: it turns out that although we do know they work, we don't know with certainty how they work. That adversely impacts the search for cheap, effective Zn-free additives.

I don't understand what you have against Zn-containing additives, and no one can prove that there is NOT any other additive which can take the place of ZDDP - it's virtually impossible to prove a negative. So why don't you tell us what your favorite Zn-free antiwear, friction modifier, extreme pressure, metal deactivator, antioxidant additive is? What concentrations are required for your add to work as well as ZDDPs? Does it affect TBN, volatility, viscosity, pour point, flash point, or any other properties BITOGers and oil formulators consider? Does it interact synergistically, antagonistically, or not at all with other additives? How much does your add cost, and how does that compare to ZDDPs? Then you could wrap it by referencing the tests which show that your add works with racing profile flat tappet cams with high spring pressures.

I'm all eyes.

 

[Jaybird]

I am touting no additive. And I have nothing against zinc. I just think that many are making unfounded assumptions.
Why do we not see mass failures of modern motocross racing bikes, with red lines of 10-15K? They are basically 1/12 of an F1 engine, with flat tappets and plain bearings. The most severe conditions we see.

The only failures I have seen were when the cam blanks for multi-cylinders were going south, but to no fault of the fluids.

 

[NovaMan]

Ah, so your theory is that cam manufacturers were selling bad blanks and then cleverly blamed it on decreasing ZDDP content in street oils in order to cover their buttockses?

Edit: Wait a second... I though F1 cars used 4-cycle engines with alcohol fuel and race oil in the sumps, and motocross bikes use 2-cycle engines with gas-oil mix as fuel and lube in one. ???

 

[Jaybird]

Well, yes...many modern dirt bikes are of the 2 cycle variety, but since 1998, there has been somewhat of a revolution in off road engines. The 4 cycle motocross racing bike was introduced to the public by Yamaha, and since, every other major race bike mfg has been also offering 4 cycle race bikes.
These high-performance engines have overhead cams running in plain bearings, pushing on flat tappet, shim adjusted buckets and titanium valves.

My only theory concerning this issue, is that folks tend to let marketing mumbo-jumbo and unfounded track myth form their knowledge base on engine oils. And I think there is mass ignorance, when it comes to engine oil additive chemistry, as a result of this less-than-accurate public perception.
I think this ignorance is also fueled by marketeers that take full advantage of the persuasive nature of sales campaigns in the guise of technical publications.

 

[sunruh]

Originally Posted By: Jaybird

These high-performance engines have overhead cams running in plain bearings, pushing on flat tappet, shim adjusted buckets and titanium valves.


high performance? oh come on now. 40hp out of 250cc is ...............um, gee that would be 160hp per liter. and a 6.0L small block chevy in the corvette would need to put out, um, wait a sec my calculator is slow, 960hp to equal that. which i'm sure they do, right?
and the chevy revs to 13,500 rpm as well, right?

plain bearings? is a steel camshaft on the aluminum journal really a plain bearing (ie no actual replaceable shell)? or merely a solid resting point when the motor is off?

and actually yamaha lit the world on fire in '97 ala mr doug henry winning the title on a YZ400F 4strk.

 

[NovaMan]

Originally Posted By: Jaybird
My only theory concerning this issue, is that folks tend to let marketing mumbo-jumbo and unfounded track myth form their knowledge base on engine oils. And I think there is mass ignorance, when it comes to engine oil additive chemistry, as a result of this less-than-accurate public perception.
I think this ignorance is also fueled by marketeers that take full advantage of the persuasive nature of sales campaigns in the guise of technical publications.

For the most part, you're probably right. I have racing friends who think that Pennzoil waxes up because it contains paraffins... they don't know it has been dewaxed. These same guys like Valvoline, but they don't know it has paraffins in it. When you say "paraffin" to them, they think of the wax their grandmother used when she made jam. They also have a cousing who is the regional manager of a quick lube shop, which only makes things worse, but these guys aren't the type you find on BITOG.

However, I continue not to see the marketeering aspect; neither the cam companies or the oil companies have come out with specific products they claim will save your cam from certain death. Is it not conceivable that a heavy pushrod valvetrain under alot of spring pressure would need an oil with more EP/AW additives than an overhead cam setup with titanium valves, even if it is a non-roller cam follower? Most adds are sacrificial, so I think you'll agree that in the long run, the heavier valvetrain with more spring pressure will chew up the EP/AW part of the add pack faster, so to last as long, you need more EP/AW add concentration. But initially, with virgin surfaces not yet broken in, consider this: the formation of an antiwear film is a chemical reaction. I don't know how much chemistry you know, but according to Le Chatlier's Principle, we can change the equilibrium position of a reaction by changing such things as concentrations. Basically, if you dump in more of one reactant (ZDDP), you will force the equilibrium toward the product side (formation of an AW film), within certain limits - you can't exceed 100% yield according to your limiting reagent, and you can't change the fundamental kinetics unless you use a catalyst or something like that.

Maybe 0.08% is past the point of diminishing returns, but someone cited an SAE paper which points to that being 0.12%, and I'd like the oil I use to last more than 45 minutes. I can't afford to doubt a recommendation which makes sense to me and is consistent with my [limited] knowledge of tribology. And when faced with a difficult decision, I always consult these two axioms: stick with what works, and go for the sure thing.

 

[Rickey]

"Maybe 0.08% is past the point of diminishing returns, but someone cited an SAE paper which points to that being 0.12%, and I'd like the oil I use to last more than 45 minutes. I can't afford to doubt a recommendation which makes sense to me and is consistent with my [limited] knowledge of tribology. And when faced with a difficult decision, I always consult these two axioms: stick with what works, and go for the sure thing."

Plus one here.
ZDDP is one additive proven to work for its intended purposes IMHO.

OK so some "study" says that .08 is the minimum required for protection at some level.
(I've seen studies before that really needed further "study")
What happens when the oil is half worn out?
Make my portion .16% just in case.

Rickey.

 

[Jaybird]

Originally Posted By: Rickey
What happens when the oil is half worn out?

Then the oil has as much life left as it has had. What is the point of this? Maybe you should make it clear what you mean by "worn out"?

I don't think you guys are seeing where I'm coming from here.
You are making the assumption that there needs to be ZDDP in the mix at all for an oil to be effective. That is a mistaken assumption. But it seems that is what you are basing your arguments on.
My stance is this...there is no way you can determine the integrity of an oil simply by looking at it's zinc content.
An oil with half the amount of ZDDP as another, could easily be twice as effective as high ZDDP level oil.
And a virgin elemental analysis, or some marketeers spew, is not going to give us much insight either.
Too many thing the analysis don't tell us, and many things the marketeer won't tell us.

 

[Loobed]

Doesn't there need to be a build-up of ZDDP on the metal surface to allow it to protect, and doesn't this buildup take time? How can the surface of a "NEW" cam be protected by ZDDP in the oil if it hasn't had time to build up a protection layer?

 

[Loobed]

Originally Posted By: NovaMan
I bought a couple quarts of Valvoline VR1 SAE30 not too long ago, and I noticed the API service rating was SM.



from the valvoline website

"Valvoline's VR-1 Racing Motor Oil has been reformulated to meet all new-car specifications, making it the right choice for the track or the street."

 

[Rickey]

Apparently a few folks refuse to grasp the fact that some engines valve trains need more than the minimum amount of ZDDP to assure proper protection during break-in.
That is their problem to own, not mine.
And I have no horse in this race.
And yes I have historically built race winning engines and hand grenades too.
Its called expensive learning by your mistakes.
So far as I am aware there is no cost effective absolute substitute for ZDDP,although there are additives that augment ZDDP.
This area is about racing engines by the way, not 3800 GM V6 grocery getters.
End of discussion as far as I am concerned.
In other words disagree if you must. Or maybe you would rather go argue with a stop sign.

Rickey.

 

[Jaybird]

Since you recognize that other adds can enhance the properties of ZDDP, how can you make any sort of statement that makes it clear as to what the level of ZDDP needs to be? You can't, is my point. All you can do is speculate.

Ask yourself why rebuild fluids specifically for cams is most often a moly product rather than a ZDDP add? Could it be that cams need EP additives for the initial break-in period?

I am firmly in the camp that says the best break-in procedure has much more to do with how the initial mismatched metals are sheared off. And to effect this situation, the metals need to see an immediate treatment as soon as friction begins. I'm talking within the first few seconds of load. A rebuild paste heavily laden with EP adds provides this immediate attention the wear surfaces need. Much more than the ppm adds of an engine oil can or will provide, at ANY treat rate.

A much more intelligent discussion would concern the actual breaking off of the metal asperities as initial wear takes place.
And just what effects this and how.

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End of discussion as far as I am concerned.
Al, is that you??? I thought you lived in TN?

 

[ted s]

which is exactly what you are doing.

"All you can do is speculate"

 

[Jaybird]

What am I speculating about, ted?

 

[Towel_Rail]

Originally Posted By: Jaybird
Ask yourself why rebuild fluids specifically for cams is most often a moly product rather than a ZDDP add?


Moly "stays put" better.