True, but from that fact it does not follow that ZDDP provides equal wear protection when bulk oil temps and engine temps are not up to full operating temps. It does follow that there will be SOME amount of protection though.
SAE Review of Dr. Schneider's Paper
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True, but from that fact it does not follow that ZDDP provides equal wear protection when bulk oil temps and engine temps are not up to full operating temps. It does follow that there will be SOME amount of protection though.
That's the question isn't it. At what temps does ZDDP become "active"? I have yet to see an answer for that.
The link I posted theorizes that pressure is just as/more important than heat for the strength of AW films, but that the ZDDP must "degrade" into ZP "precursors" before it becomes effective. No explanation/theory is given for this.
I agree buster. I like ZDDP + boron add's. My problem is that if you take the ZDDP from 1200+ ppm down to 750ppm's it take more then 60-150ppm of boron to make up for it! I think they need to at least replace the ZDDP removed with an equal amount of boron additives. I think that moly really should not exceed about 200ppm in most applications. I like moly but I really wounder about how much it might be interfering withthe little ZDDP thatis left in SM/GF3 GF4 oils.Seeing how calcium has show to be realtively benign to AW/EP additives and can if overbased enough act like a short term AW additive also be increased in PCMO. I think that with the OCI getting pushed out by most OEM's higher levels of calcium make sense to increasethe TBN.
Tempest, I agree it would be nice to know. In the end though the important thing to know though is that it works in the field and to take advantage of that. It has been used for 70 years with out full understanding of how it works. I would rather have it in my oil then not! Now if one of the big oil companies wants to market an oil that has 800ppm of ZDDP, 3000ppm of calcium, 500ppm of boron, 200ppm of moly and a little silicone for antifoam I would be happy to buy a case or too. This would especialy be true if it had high ester content. I do not see that happening though anytime soon. If you look at most of the additive packages of OTC oils they just keep makeing them weaker and weaker with a few exception.
The author's state in the introduction of the paper:
"The overall purpose of this research project is to develop lubrication systems that can greatly reduce the need for customer oil changes while protecting the engine from excess wear."
However, the conclusion in the abstract is:
"These results suggest that concerns of wear between the rings and cylinder bore may not be a roadblock to extended oil-change intervals."
The unstated assumption is that ring and cylinder bore wear dominates the goal of "... protecting the engine from excess wear."
This may or may not be true, depending on other engine design factors.
"The overall purpose of this research project is to develop lubrication systems that can greatly reduce the need for customer oil changes while protecting the engine from excess wear."
However, the conclusion in the abstract is:
"These results suggest that concerns of wear between the rings and cylinder bore may not be a roadblock to extended oil-change intervals."
The unstated assumption is that ring and cylinder bore wear dominates the goal of "... protecting the engine from excess wear."
This may or may not be true, depending on other engine design factors.
At what temps does ZDDP become "active"? I have yet to see an answer for that.
Depends on what ZDDP is used depending on Carbon chain and alcohol type it varies as does the AW and AO effect ZDDP with better AW will have lower AO and ZDDP with a good AO effect will have a bad AW. The ZDDP with best AW is active at lower temps but it needs other AO to make a good oil.
and exactly what temp i do not know tho.
bruce
Depends on what ZDDP is used depending on Carbon chain and alcohol type it varies as does the AW and AO effect ZDDP with better AW will have lower AO and ZDDP with a good AO effect will have a bad AW. The ZDDP with best AW is active at lower temps but it needs other AO to make a good oil.
and exactly what temp i do not know tho.
bruce
Thanks for the information bruce. Great stuff as always.
John, wouldn't you also want some magnesium in there as well?
I do like your formulation though.
I do like your formulation though.
Just thought of another question:
Quote:
Just thought of another question:Is it typical to mix different types of ZDDP together to get good AO and AW? Or do you need to stick to a single species for best affect?
yes can mix but depends on what you want a race oil will be geared toward AW protection a long life oil will be toward the AO or a blend between a lot of this data is NOT avalible since the majors that have run various engine stands keep it secret.
Also you will see that boron esters can replace ZDDP at a lower overall rate since there is a lot of synergy between them.
bruce
Thanks once again bruce. Johnny on the spot with more great info.
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