Tribologists: Oil with no moly. Do additives+base perform a similar function?

Messages
658
Location
EU
G-Man did two VOAs on the German 0w-30 Castrol, the one that we suspect is composed of a high percentage of esters. The additive elements in the two analyses were:
code:
  
Ca	3634	2754
Mg	114	120
P	841	795
Zn	938	906

How does this oil protect? What components/component combinations perform analogously to the moly found in other oils, if possible? Please compare and contrast moly oils with this one.
 
Messages
8,937
Location
SC
MolaKule and others have said that modern hi-tech esters can perform "double duty" in motor oils, reducing the need for certain additives that are typically found in a VOA. When Mobil introduced SuperSyn, it was assumed that would be the case with this newest formulation of Mobil 1. However, as VOAs and UOAs (and subsequent reformulations) have shown, that's not the case. Mobil no doubt uses some of its next generation esters in the SuperSyn formula, but they don't use them in sufficient quantities to obviate the need for other EP/AW additives like moly and boron. There was a VOA of Mobil System-S posted which showed very low additive numbers, but a very high TBN. It was initially theorized that this oil (available only in Europe) was Mobil's super-duper ester rich synthetic. The person who did the VOA said that it's more expensive in Europe than Mobil 1. After some research by me and a few others, it was determined that the System-S is acutally a Group III based oil. HOWEVER, it could be Group III based and still have a significantly higher concentration of the next generation esters in it than does Mobil 1. In fact, I suspect that's the case. This oil is probably a blend of ExxonMobil's ExxSyn (a Group III wax isomerate) and esters. That would explain the relatively low additive treat rate as well as the price difference between it and Mobil 1. But because of Mobil's commitment to labeling only a PAO based oil as "fully synthetic," they do not market the System-S as a full synthetic oil. As for the Castrol Formula SLX 0w30 (sold in the US as the German made Syntec), the high concentration of esters in the base oil blend are doing double duty as well. The one UOA we've seen of this oil shows it does protect, and protects well even without moly and boron. And like Mobil's System-S, the German Syntec may very well be a blend of Group III and esters, which for Castrol isn't a problem as far as calling it a "full synthetic." However, with it's extremely low pour point, the percentage of Group III in the blend would have to be very low. (And it may not have any Group III. It could very well be a PAO/ester blend. I'm just speculating.)
 
Messages
1,874
Location
Ocala, Florida
Of course most of you know who I am and my limited background. Anyway, let me give you my ideas and PERSONAL OPINIONs on this subject. First, many chemists/tribo's tell you that the synth base fluids will protect better, some even state better "film strength". Question is does synth based oils protect better... q1-AGAINST WEAR? or q2-AGAINST OIL BREAK DOWN? My answer, q2, against oil break down, Not against wear. Understand I'm talking about standard oil drains, not pushing extended. Extended drains is where synth stocks will prevail, no doubt but here's the catch, provided the additive package holds up and in many/most cases we see, most are changing filters and adding fresh additives with new top off oil to accomplish this as well. Why do I say this... My argument to this is, To protect against wear you must have a hydrodynamic layer of oil between the two surfaces to keep them from scuffing each other.  - So, in an automotive application how is this done. The oil pump provides say 40-50lbs of oil pressure between the rod bearing and the crank. This pressure will provide that "wedge" of oil and provide enough oil between the parts. What happens if the oil pressure is only 25-30lbs at idle then you put a load on it during acceleration?, You then don't have that wedge effect, and so it can be squeezed out momentarily, thus the scuffing happens.  - So, how does a synth base oil differ and keep it protected better? well, if flow resistance is pressure, and there is little flow, which creates less pressure, then when the force of the two objects(bearing/crank) squeeze together, and based on the fact that we've determined that oil flows at a certain rate and WILL take the least path of resistance, then that wedge or hydrodynamic film doesn't exist, thus the reason why anti scuffing/anti wear additives are used. One of the things I've noticed is that EVERY SYNTH OIL has an abundance of these additives. As Gman pointed out about M1, when the first came out with their first version of SS, it failed miserably on the timken, but soon afterwords, moly (among other additives) were introduced to assist the oil and now, it provides excellent resistance to hydrodynamic shearing on the timken compared to earlier comments. Point is, Hydrodynamic wedge effect must be present to create that barrier between the parts and under normal conditions, this does not happen except in hwy driving all the time. So, to say that the synth base stock is going to provide better film strength, I personally believe that we are referring to the molecular level as the CH chains are more resistant to oxidation in a synth and will not shear down thus losing it's viscosity as easily. This doesn't mean that it provides better hydrodynamic film strength as that is contingent to oil flow(min) and (max)pressure which is developed from the oil pump and engine bearings(clearences). So, is the additive levels less in synth's? of course there are areas in synths that do not need as much if any additives when it comes to synth's but that's more based on viscosity improver's and cleaning additives all of which normally helps enhance the base oils longivity. When if comes to AW/FM'additives, I do believe that is one area that will not at this time be reduced based on reliance of the new synth base oil. The base oil will have to be able to develop a barrier level of sorts to allow for lessen amount of aw/fm additives to be reduced/ eliminated. Another point is as much as many fail to see the timken as a valuable tool in seeing how an oil performs, I find that if an oil won't provide an effective barrier protection on this, it IMO lacks protection in load and shear in comparision to other oils. All mechanical equipment experience this shearing at certain times. As of yet, I've not seen any oil that doesn't have AW/FM's in their oils, so a synth based oil or not, that last line of defense and is a very critical part of any oil thus you see an abundance of aw/fm's in synth's. Take out these additives from Amsoil's best oils(which they havev higher levels of zddp than api allowed) and you'll see, that's one of the biggest differences in wear protection with that oil, same with redline, take out all that moly and zddp, they use an excellent base stock, yet you notice the extreme load of the aw/fms. If one of these chemists/tribo's has nothing but a base oil with no aw/fm's that would provide this exceptional level of wear protection under a shearing condition, I'd love to see it If you remember watching my video on M1's SS when it first came out, I was not able to get it to provide ANY, not ONE ounce of protection on that machine yet all the other oils did. I had to finally just quit grinding on it. Now, understand this isn't to say that it can't happen and that they can't create a base oil to replace the aw/fm additives. As of yet,I've seen no evidence shown that a hydro dynamic film exists all the time under all situations and as of yet, I've not seen one synth oil worth using not have aw/fms, This includes the best of the best, LE,Schaeffers, Redline, Amsoil, etc...
 
Messages
5,358
Location
Gone
I went to the Castrol Deutschland website screens which address motor oil http://www.castrol.de/schmierstoffe/1_motorenoel/motorenoel_1.html ...they present an extended explanation of the various aspects of motor oil (probably simplistic for Bob, Terry, 'Kule, Johnny and others of our experts); I machine translated the part on wear prevention additives...it's not great but you can get the idea of their thinking. QUOTE Through suitable additives, one can construct on Gleitflächen extremely thin layers, whose scissors stability is substantially slighter than that of the metals. It is under normal conditions firm, under wear conditions (pressure, temperature) however gleitfähig. So an excessive wear (eating and/or welding) is prevented. As required (Metall/Metall-Kontakt) the layers permanently newly are formed through a chemical reaction Extreme press original and Antiwear (EP / AW) additives The oldest EP additive is pure sulfur. EP/AW-additive boundary area active materials are and can polish contained in that group the elements zinc, Phosphor and sulfur in different combinations. The best known representative of this type is the Zinkdithiophosphat - ZDDP- that functions in addition yet as an aging additive and corrosion protection additive. In the Anfahrphase of the motors, the condition of the Mischreibung lies before (transition between glide and ! custody friction). There, where a metal/metal-contact exists, emerges warmth. The zincs-/Phosphorverbindung reacts at the surface and forms an additional layer protecting before wear.
 
Messages
6,388
Location
Washington St.
Just a note to say that the hydrodynamic wedge of oil is not provide by the oil pump. The oil pump certainly provides the oil, but the layer of oil that separates a rotating journal in a round bearing is created by the rotation of the journal pumping the wedge of oil into place. The journal actually rises and rides of this wedge of oil that it creates by this pumping action. The oil for the hydrodynamic layer can come from any source suitable for the physical arrangement and surface speeds (figured in inches per second or other linear speed measure) and other conditions...the bearing might be partly submerged in an oil sump, or there might be loose fitting rings that ride on a slow turning shaft and carry oil from a sump to the bearing surface. Oil pump pressure is certainly necessary for the lift that puts the oil film between the parts in oscillating bearings such as wrist pins, etc. Sliding surfaces that don't tilt and have a way to trap a wedge of oil rely on boundary lubricants. Ken [ July 20, 2003, 03:07 PM: Message edited by: Ken2 ]
 

MolaKule

Staff member
Messages
21,725
Location
Iowegia - USA
True, Ken2. As for sleeve bearings, the flow of oil created by the oil pump is mainly used for cooling the bearings. A rotating journal will naturally suck in oil (assuming a hole in bearing and bearing in oil bath), squeeze it, and send it out the bearing ends. However, without flow, the bearing temperatures would rise to an uncomfortable level to the point the bearing would soften and start to "slough-off" metal because of the heat. Another reason for oil flow is to carry away dirt particles for filtering. In addition, a bit of "hydrostatic" oil pressure from the pump does help to maintain a slightly thicker oil film. [ July 20, 2003, 03:23 PM: Message edited by: MolaKule ]
 

MolaKule

Staff member
Messages
21,725
Location
Iowegia - USA
quote:
How does this oil protect? What components/component combinations perform analogously to the moly found in other oils, if possible?
Moly TDC is a good AW/FM additive and fairly moderate wrt cost, as of now. In lieu of moly, one can use the new calcium concentrates which provide a measure of AW/EP functionality as well as provide an DD agent. See the "question of the Day" thread number XII on multifunctional additives, which is pretty comprehensive. In addition, Castrol could be using an Antimony AW/EP additive that does not show up in the analysis. There is also the boron additives that one could use, albeit it does not appear to be used in the new Castrol under discussion. There are sets of esters that perfrom the AW/EP function as well as FM functions. These esters are very expensive, but with calcium concentrates and these new esters, the Castrol is most likely relying on these ester additives and calcium particulates to perform these functions.
 
Messages
713
Location
Pennsylvania
quote:
Originally posted by Ken2: Just a note to say that the hydrodynamic wedge of oil is not provide by the oil pump. The oil pump certainly provides the oil, but the layer of oil that separates a rotating journal in a round bearing is created by the rotation of the journal pumping the wedge of oil into place. The journal actually rises and rides of this wedge of oil that it creates by this pumping action. The oil for the hydrodynamic layer can come from any source suitable for the physical arrangement and surface speeds (figured in inches per second or other linear speed measure) and other conditions...the bearing might be partly submerged in an oil sump, or there might be loose fitting rings that ride on a slow turning shaft and carry oil from a sump to the bearing surface. Oil pump pressure is certainly necessary for the lift that puts the oil film between the parts in oscillating bearings such as wrist pins, etc. Sliding surfaces that don't tilt and have a way to trap a wedge of oil rely on boundary lubricants. Ken
Well, sorta yea kinda, in an engine, the upper shell of a main bearing (note: all bearings are far from the oil supply) there is an annular groove, the pump fills this with oil and the 'stiction' of the rotating crank 'grabs' the oil and rolls it into the wedge when the oil passage holes are not there - its sort of a 50-50 split duty. (I tell you I lost a REALLY good link with pics of this). as for the rod bearings, oil under pump pressure in the crank is flung 'outwards' towards the crank bearings at tremendous pressure due to centrifugal force and is presented to those bearings, who have no annular groove. This action within a crankshaft is why the term 'priority main' oiling is so important, the main bearings must be given the most pressure oil at the most generous supply as the faster the crank spins and the longer the stroke, the more the throws of the crank actually SUCK oil away from the mains! (early versions of the gm 660 engine (2.8L) in hipo or abusive situations, would suck the middle mains dry as it was not priority main.) anyways, the point being, oil must be presented at either high pressure or via tricks like grooves to get the ball rolling...
 

YZF150

Thread starter
Messages
658
Location
EU
Pablo, yes, and it was the absence of Mo that gave me the idea for my question. Since moly is so regularly discussed here, and, this German oil is also somewhat topical of late, the lack of the one in the oil and the scarcity/anticipation regarding the oil itself serve to raise the issue. MK, also suggests Sb as a possible adjunct additive to the Ca and esters. Question for MK: you’ve addressed newer ester technologies in several threads lately. This oil, however, has been around for some years in Europe. Do you distinguish between the esters that perform the AW/EP functions and which are expensive from those that are likely to be in this German oil? Hmmm. I wonder if Blackstone can and would test for Sb if requested. Anyone know if this is element can be requested? Please respond if you know. I think that I’ll email them, too.
 

MolaKule

Staff member
Messages
21,725
Location
Iowegia - USA
quote:
Question for MK: you’ve addressed newer ester technologies in several threads lately. This oil, however, has been around for some years in Europe. Do you distinguish between the esters that perform the AW/EP functions and which are expensive from those that are likely to be in this German oil? Hmmm. I wonder if Blackstone can and would test for Sb if requested. Anyone know if this is element can be requested? Please respond if you know. I think that I’ll email them, too.
Yes. In fact, they could have base esters and AW/EP esters. The Sb testing may cost a bit more as costs go up for the number of elements tested. But, its worth a try.
 

YZF150

Thread starter
Messages
658
Location
EU
Points taken and understood. So, with no moly "plating" or uptake from this oil, what is the physical chemistry of the protection offered by this oil? In lieu of plating, what remains?
 
Messages
8,937
Location
SC
quote:
Originally posted by YZF150: Points taken and understood. So, with no moly "plating" or uptake from this oil, what is the physical chemistry of the protection offered by this oil? In lieu of plating, what remains?
Well, as Bob points out, as long as the hydrodynamic layer remains, the "plating" of an EP/AW additive is totally unnecessary. My understanding of why certain ester-based oils can get by with less EP/AW additives is because the ester base oil is LESS prone to "squeeze out" even under the most extreme pressure. I'm sure the polarity of the esters has something to do with it, but we're getting out of my element here. MolaKule can explain it.
 
Messages
47,716
Location
Duvall WA - Pacific NW USA
YZF - don't forget there are other AW additives besides Mo, and some/most are still used in oils that contain Mo. P, Zn, Sb and B come to mind. Mo is not the magic elixir for all oils, analogous to synthetic base stocks not making the magic oil not requiring any AW additives. A formulation can work on paper and a formulation can work as witnessed in a UOA. The two sometimes are not as linked as we want to think. buster - cost is probably #1. [ July 20, 2003, 12:53 PM: Message edited by: Pablo ]
 
Top