ZDDP and Detergent ?

[OilSnob]

I couldn't quite find references to this in searches and would like to know the trib-pros opinion of this statement:
Quote
...try an oil change using a high-detergent diesel oil for roughly 100 to 200 miles. The reason behind this is that detergents tend to strip away ZDDP from the valleys or crevices created in the cylinder wall during the honing process. By removing the excess ZDDP by running a high-detergent oil, the engine's excess oil use returned to normal...
or about this 2018 article in general. It doesnt jive with what I thought I knew about detergents. https://www.onallcylinders.com/2018...h-off-the-shelf-motor-oil-to-save-money/

It reads to me as almost an advertisement and not sure what to think.
Thanks for your opinion.

 

[MolaKule]

Much misinformation and misunderstanding followed a paper about Detergents and AW additives vying for friction surfaces.

With a balanced formulation there is no concern.

High detergent HD oils DO Not strip away the AW film, otherwise we would see engines failing in short order.

 

[FCD]

Interesting, but it does make me wonder :

Let's take two hypothetical oils, both have the same AW additives but one has a much stronger detergent / dispersant package then the other, would the oil with the beefier detergent / dispersant package take longer to form its AW film, or not?

I've read something along the lines that for the average oil, it takes 8-10h of engine running time for the AW film to start to appear after an oil change.

 

[OilSnob]

Originally Posted by MolaKule
Much misinformation and misunderstanding followed a paper about Detergents and AW additives vying for friction surfaces.

With a balanced formulation there is no concern.

High detergent HD oils DO Not strip away the AW film, otherwise we would see engines failing in short order.


Thats why I think that article is just bunko advertising.
I think I know the journal article you're speaking of, it is cited by other commercial products as a knock against using "Diesel engine oils." I read it and IIRC the takeaway was that the HDEO needed another 10*c of heat to apply the AW film and so the theory is that if you use HDEO and subject it to constant low heat cycles that it can accelerate wear. Meaning high detergent levels are bad for engines that are short tripped.
Does this sound right?

I noticed that VR1, along with a load of ZDDP, has pretty high detergent levels so can I assume its similar to HDEO. Plus a race car is getting fully heat cycled anyway.

 

[RDY4WAR]

I imagine the type of ZDDP may play a role. HDEO uses more primary type ZDDP where as PCMO uses more secondary type ZDDP.

 

[OilSnob]

Originally Posted by RDY4WAR
I imagine the type of ZDDP may play a role. HDEO uses more primary type ZDDP where as PCMO uses more secondary type ZDDP.


Talk about speaking Greek at me

...care to dumb that down a bit for me?

 

[RDY4WAR]

Originally Posted by OilSnob
Originally Posted by RDY4WAR
I imagine the type of ZDDP may play a role. HDEO uses more primary type ZDDP where as PCMO uses more secondary type ZDDP.


Talk about speaking Greek at me

...care to dumb that down a bit for me?


ZDDP contains zinc, phosphorus, and sulfur attached to alkyl groups. You can change the characteristics of ZDDP by changing the alkyl groups. ZDDP that uses more reactive secondary alkyl groups is mostly found in gas oils since it activates at lower temperature and pressure. This benefits a gas engine that sees frequent cold starts and short trips. ZDDP that uses more thermally stable primary alkyl groups is mostly found in diesel oils since they lug along at 1500 rpm for hours unend and go tens of thousands of miles between oil changes. Primary type ZDDP has a lower coefficient of friction and is less damaging to emissions components, but is weaker when it comes to wear protection. Secondary type ZDDP has a higher coefficient of friction and more damaging to emissions components, but is better geared toward wear protection.

More information about ZDDP can be found in this paper...

The History and Mechanisms of ZDDP

Here is a small excerpt from that paper where it mentions the roles of primary and secondary ZDDP.

Here is a graph showing the relationship between the types of ZDDP compared with their friction coefficient and wear protection.

 

[Kamele0N]

Back to the OP's question....

1997 LC in my sig...

Bought cca 2yrs ago...its/was

well used...when purchuased I was barely able to handle its oil consumption...

Now it has a decent GTL HDEO in its sump (4300ppm of Ca)... Link: https://www.oil-club.ru/forum/topic/14970-shell-rimula-r6-m-10w-40-api-cf-acea-e7-e4-mv-2285/

And after a year of use with that oil....I stoped with topping off its oil...

Most probably because it was neglected (almost no maintenance) its oil rings and rings on turbo bearing were stucked...

I just think that just detergents did their job (luckily for me)...

 

[FCD]

However the type of Zddp found in HDEOs has proven itself to also work just fine in gasoline engines, specially older flat tappet engines.

 

[OilSnob]

TY for that RDY4WAR

 

[OilSnob]

Originally Posted by FordCapriDriver
Interesting, but it does make me wonder :

Let's take two hypothetical oils, both have the same AW additives but one has a much stronger detergent / dispersant package then the other, would the oil with the beefier detergent / dispersant package take longer to form its AW film, or not?

I've read something along the lines that for the average oil, it takes 8-10h of engine running time for the AW film to start to appear after an oil change.


This article: S.Shirahama and M. Hirata, Nippon Oil Co., Yokahama, Japan, "The Effects of Engine Oil Additives on Valve Train Wear," Lubrication Science 0954-0075, 383.
Is cited by ZDDPlus and a couple of others oil brands as evidence that HDEO should not be used in a flat tappet engine, of course they say you need to buy their product instead. I was able to find it and read it totally sober with my thinking cap strapped on and all I could find it to imply regarding this is that -"high" levels of detergents would delay the decomposition of the AW additives into a film by 10*c-(I can't recall the exact temps but I recall they are typical to reach with a decent run time.) And that repeated used without reaching or maintaining these temps would result in stripping away the layer faster than it can be reapplied. So what I take away from this is that its fine so long as each heat cycle with a HDEO or VR1 is given time to reach these slightly higher temps and maintain them for longer than a trip to DQ and back.
Im pretty sure the article didn't mention different types of ZDDP.

 

[RDY4WAR]

As far as the types of ZDDP, I know of a certain oil used in many NASCAR engines for years only contained 850 ppm of zinc from ZDDP and 950 ppm of phosphorus from ZDDP and phosphate ester. It was (and still is) all C4 secondary ZDDP. It was primarily light PAO based with 15% POE. KV100 of just 5.8 cSt and HTHS of 2.1 cP. Yet it kept cup engines alive when they ran solid flat tappets with over .800" lift, over 700 lbs open spring pressure, lobe intensity that rivaled a lot of solid roller cams, and turning 8000+rpm for 500 miles straight. Granted the engine was torn down and rebuilt after each race week, but you rarely saw any oil related engine failures or just engine failures in general during the race. The fact the oil also had over 1500 ppm of trimer moly / organomoly blend FM may have helped that as well. This oil also contained just 350 ppm of Ca. High intensity, short duration.

Did the lower detergent help ZDDP work more efficiently at a lower concentration?

Did the high amount of FM help bolster the low ZDDP?

Did the type of ZDDP make more of a difference than the lower detergent and higher FM?

I haven't a clue.

I just know it worked. As far as this discussion is concerned, HDEO could be the same principle but in reverse.

 

[FCD]

Maybe the primary ZDDP that HDEOs use isn't exactly designed for gas engines, but i think we all could agree that HDEOs are a proven safe choice for older flat tappet engines.

 

[LeoStrop]

This is a good link provided by claluja about ZDDP AW film formation.

It was posted on this thread