New motor oil wear problems on older engines

[geeaea]

When you switch fundamental chemistries you can sometimes get a radical seating process that will disrupt some things. More than likely your seals were already shot or rigid and the semisynthetic oil disrupted that state. When I switched from Delvac 1 to Rotella T synthetic (one a PAO the other a Group III XHVII formula) I got consumption within 3000 miles where I had gone 12k without any. The consumption receded with subsequent oil changes and was reduced to zero again.

I would see if Auto-Rx could fix your RMS if you're not able to replace it (not an easy - but doable- task for the DIY'r). Your condition sounds pretty severe ..but I'd try it anyway (Auto-Rx).

HM oils (typically) use esters for some seal swelling and the HM oils typically reside in the upper limits of whatever viscosity grade they're in.

Keep in mind that the further your spread in normal and cold temp spec, the more correction fluids are employed to meet those specs. A 10w-40 IS a 10 weight oil that appears like a 40 weight @ 100C. That's why it's a 10w-40. It appears exactly like a 10 weight @ -25F. What most people have a hard time figuring out ..is that a 10 weight oil @ -25F is like cold glue. It's just thinner cold glue than what a 40 weight would be at that temp. They have false visions of it pouring like water at cold temps and pouring like tar when hot.

Anyway ..bigger spread ..more polymers to "fake" the hot viscosity. These polymers are what "shear" and lower the viscosity and an lead to sludge formation in many cases. The only true weights in conventionals are straight weights. The multiviscs are oils that "simulate" higher viscosities at higher temps. Synthetics are not usually this way. A "straight" 40 weight synthetic may qualify as a 10w or 5w without any correction fluid.

 

[corbinafly]

Let me share some notes from Red Line about zddp.

Lubricants Notes from Redline

By Roy Howell, Chief Chemist, Redline Synthetic Oil Company, Formerly of Lubrisol, 7 April 1992

Notes taken by Jack L. Poller.
The surface gets plated with either Iron Phosphate or Iron Sulfate, both of which are softer than the base Iron. This chemical reaction occurs in the 300 to 400 F range, and the Zinc is a temperature controlling carrier (controls the temperature at which the reaction occurs. When the two metal surfaces come in contact, a small amount of the surface plating is 'scraped' off of the surface. This is replenished by more ZDP contact with the metal. This action prevents the metals welding through heat generated by high friction contact. The ZDP in the lubricant may last up to 20,000 miles.

So, we have a FIFO type thing with a full magazine to "refill" the gap.

So, I reassert that a lower zddp starting level will mean that you will have less latitude in length of OCI.

This is somewhat, IIRC, supported in the current pushrod engines offered by DC. They spec SM oil over 5000 mile OCI's ..as opposed to most everyone else, with roller valve trains can go much further (although this is not a given just because they have roller valve trains).

Sorry, but again, do we know how quickly the "replenishing" occurs? Would the existance of more zdp speed up the process? I would think so. With such small percentages of zdp in the oil, one would think that it could take some time before the proper molecules come in to contact with the "scraped" area. It might not take very long, but who knows?

 

[geeaea]

The proportions between the zdp levels between SJ:SL and SL:SM are not as broad as the differences between our beloved 4.0 and those valve trains that we're warned about in relative severity of need. Keep your eye on the obsession that EcoMike is perseverating on needlessly. Our 4.0 engines are "COMMON AND MUNDANE" sporting COMMON spring rates. If our 4.0 can tax the SM zdp level in normal use ...then SL surely can't do squat for the home equity Jeg's engines ..nor save the cam mans from disclaiming themselves to death out of fear of a consumer insurgency.

..but you're not bringing much to the table here, yourself, are you? You're merely throwing conjecture in contrarian countermeasures.

Do you have anything to support your supposition ..or am I supposed to field every curve that you pull out of your behind? (big smile).

 

[Ecomike]

Ecomike,

ZDDP is sacrificial ...there is no "thickness" to it.

If you happen to have a surface break through the hydrodynamic layer ...zddp is there to "throw itself in harm's way".

Here's a brief excerpt from a GM engine development engineer. It's in regard to how the software was set up around ZDDP decay for the GM OLM. ZDDP decay is the fundamental root calculation in the length of service for oil. The OLM has something like a 50% safety factor for stating when the oil is shot. That is, it decays PRIMARILY by ZDDP decay and then is further decremented by trip length, open loop operation, blablabla.

So, when you're quibbling over the difference between 800 ppm ..and 1200 ppm ....you're looking at the difference between a 7500 mile OCI and a 10,000+ OCI in viable zddp concentrations ..NOT grinding your cam to dust.

On the quibbling over 800 versus 1200 ppm of ZDDP, I have yet to see any guarantee from the oil companies that they will continuing using any ZDDP in their SM formulas. Have you seen an API SM spec that sets any minimum concentration on ZDDP in the SM formulas? The API SL spec set a minimum ZDDP concentration, from what I have read, but they did not set a minimum ZDDP concentration for SM oils that I know of.

On your claim regarding ZDDP "there is no thickness to it" :

Quoting from:
http://uhv.cheme.cmu.edu/pubs/SurfChemTrib.130.pdf

Pg 13:
"Studies of film structure, composition and thickness
Many studies have focused on the thickness of the films produced by ZnDTP. Gunsel et al.[47] used ultra-thin-film interferometry to monitor ZnDTP film formation at various temperatures. A solid film appeared to be forming, under rolling conditions, once a threshold temperature of 130°C was reached. At 200°C, the film grew, over a period of an hour, to a saturation thickness of just over 40nm. Using a similar method, which enabled reaction films to be observed outside the contact in a mixed
rolling/sliding regime, Taylor et al.[54] were able to show that the films could be as thick as 200nm, but depended strongly on the slide-roll ratio. XANES studies[38] have shown that the films are of the order of 40-100nm thick, depending on the concentration of ZnDTP in solution."

Also see fig 10, pg 16!

 

[Ecomike]

Let me share some notes from Red Line about zddp.

Lubricants Notes from Redline

By Roy Howell, Chief Chemist, Redline Synthetic Oil Company, Formerly of Lubrisol, 7 April 1992

Notes taken by Jack L. Poller.
The surface gets plated with either Iron Phosphate or Iron Sulfate,

Corrections, it is zinc and iron polyphosphates and iron sulfide (FeS) not iron sulfate (SO4).

both of which are softer than the base Iron. This chemical reaction occurs in the 300 to 400 F range, and the Zinc is a temperature controlling carrier (controls the temperature at which the reaction occurs.

There are many published reports showing that the reaction is not just thermally driven or controlled, but is also mechanically generated i.e. two surfaces rubbing mechanically against each other without substantial temperatures involved. And the (2) ZDDP reaction films formed by the two different processes, thermal and mechanical, are different in their poly-molecular properties.

When the two metal surfaces come in contact, a small amount of the surface plating is 'scraped' off of the surface. This is replenished by more ZDP contact with the metal. This action prevents the metals welding through heat generated by high friction contact.

The ZDP in the lubricant may last up to 20,000 miles.

MAY? It also MAY NOT!
Where is your data to support this 20,000 mile theory?

There is no try (may), there is Do (will), or Do not (will not)! LOL, quote from another enlightened being, no not G'Kar.

So, we have a FIFO type thing with a full magazine to "refill" the gap.

So, I reassert that a lower zddp starting level will mean that you will have less latitude in length of OCI.

Then why did the oil companies waste money using higher concentrations in the older formulas?

This is somewhat, IIRC, supported in the current pushrod engines offered by DC. They spec SM oil over 5000 mile OCI's ..as opposed to most everyone else, with roller valve trains can go much further (although this is not a given just because they have roller valve trains).[/quote]

 

[BlackJax]

Shell Rotella Synthetic 5W-40 (6bt). Works great. Never had an issue (290k/miles)

 

[Ecomike]

Sorry, but again, do we know how quickly the "replenishing" occurs? Would the existance of more zdp speed up the process? I would think so. With such small percentages of zdp in the oil, one would think that it could take some time before the proper molecules come in to contact with the "scraped" area. It might not take very long, but who knows?

Replenishment is a rate limited reaction step, and is not instantaneous. It is limited by local mechanical friction, localized surface/oil temperature, ZDDP concentration and the metal surface interface and detergent concentration at the metal surface interface.

Higher detergent concentrations reduce the surface film formation rate (film being defined here as containing zinc and iron polyphosphate and sulfides, et.al.). Higher temperatures and higher friction increase the film formation rate. Lower ZDDP concentrations have lower, slower film formation rates.

The trick is to get a balance were the replacement film forms as fast as the existing film is worm away, at least until the OCI has been reached, if not longer since many of us frequently have our lives interupted by events that unexpectly increase our actual OCIs beyond our planned OCIs.

 

[corbinafly]

The proportions between the zdp levels between SJ:SL and SL:SM are not as broad as the differences between our beloved 4.0 and those valve trains that we're warned about in relative severity of need. Keep your eye on the obsession that EcoMike is perseverating on needlessly. Our 4.0 engines are "COMMON AND MUNDANE" sporting COMMON spring rates. If our 4.0 can tax the SM zdp level in normal use ...then SL surely can't do squat for the home equity Jeg's engines ..nor save the cam mans from disclaiming themselves to death out of fear of a consumer insurgency.

..but you're not bringing much to the table here, yourself, are you? You're merely throwing conjecture in contrarian countermeasures.

Do you have anything to support your supposition ..or am I supposed to field every curve that you pull out of your behind? (big smile).

Not trying to counter you, but rather get to the bottom of this. Thinking out loud is a specialty of mine. I'm definitely not saying that I'm right/your wrong. So far I think there are many unanswered questions that are preventing me from being able to take a definite stance on all this.

Life is one curve ball after another...whether it's from my behind or not.:wave1:

 

[Ecomike]

200lbf (force) there is no spec for the seat pressure ..but I imagine it's quite low. That's from the 1999 FSM. It's, naturally, the same for the 2.5


I think that you anoint our beloved 4.0 with too many magical potent powers that it does not have in terms of valve train load.

Haynes lists the 2.5 L spring pressure as 200 lbf and the 4.0 L as 220 lbf max. Why would you think the 2.5 L would be the same as the 4.0?

Now I refer back to the original lnenginering.com web site that referenced test data show 0.095 ppm as the best MINIMUM ZDDP concentration to minimize cam and lifter wear for a 205 lbs pressure spring rate. 0.095, 950 ppm is more than the 800 ppm you accuse me of quibling over. If I start out with 1200 ppm, I would hope to still have 950 ppm before the end of the OCI. That certainly is not going to happen if I start out with 800 ppm, or worse something like 500 ppm that has been documented in one of the SM oils already, namely the Havoline oil. So who's quibling here?

 

[bewilderedbeast]

Well, I'm running Havoline in mine, these days, it's the SM flavor, and the UOA's are excellent-I realize you don't think that matters--and the engine is quiet, smooth and strong.
I would bet that in the far-off future, when my engine gives it up, it won't be due to my choice of oil.
I will keep an ear to the ground, listening for accounts of the expected huge numbers of 4.0's dying due to SM oil usage.

 

[Ecomike]

According to this July 29th, 2007 post at Shell they EXPECT their new CJ-4 Rotella T oil to pass the API tests before the October 2007 deadline.

Hmm, as I recall the labels on the store shelf for this stuff say it already passed API CJ-4 tests. Did I miss something?

:nono:

http://www.imakenews.com/rotella/e_article000530494.cfm?x=b11,0,w

 

[Ecomike]

Well, I'm running Havoline in mine, these days, it's the SM flavor, and the UOA's are excellent-I realize you don't think that matters--and the engine is quiet, smooth and strong.
I would bet that in the far-off future, when my engine gives it up, it won't be due to my choice of oil.
I will keep an ear to the ground, listening for accounts of the expected huge numbers of 4.0's dying due to SM oil usage.

So what was the Zn & P concentration in that last UOA?

 

[geeaea]

Haynes lists the 2.5 L spring pressure as 200 lbf and the 4.0 L as 220 lbf max. Why would you think the 2.5 L would be the same as the 4.0?

Haynes is good enough ..but the FSM is one I'll take to the bank. Haynes is correct ..and I'll even correct myself. There is a seat pressure spec.

Valve open: 202-218 (200 - nuff said)
Valve closed: 71-79
This IS the 2.5 spec and it is IDENTICAL TO THE 4.0 ..same rods ..same pistons ..same valves..same springs.

Why would you think that starting off with 1200 ..with 1200 being "enough" and expecting 900 ppm to be left in suspension at the end of the OCI? This infers that you feel that 300 ppm is all that will be sacrificed in the entire OCI...

Surely you need to give me the rationale behind this assertion here. It surely doesn't add up. Not rhetoric recital ...rationale.

Why would less than 300 ppm of contact rubbing/microwelding prevention require 4 times that saturation to adequately maintain the protection layer.

Mix the numbers up as you please. More ...less ..whatever.

Againm, our 4.0 is as COMMON as a 3.8 Buick ..anything with a pushrod is too.

 

[bewilderedbeast]

So what was the Zn & P concentration in that last UOA?

As I posted on page 9 of this thread, zinc was 650 ppm, and Phos was 550, after 3k miles. Other UOA's show similar levels.

The newer Deposit Shield UOA's show very similar amounts, while VOA's on the new stuff indicate that it starts out at about 850 for zinc and 750 for phos.

 

[Ecomike]

Interesting, I had not heard anything good about Havoline oil in decades. I ran across a post somewhere today that said Havoline has a bunch of molybdenum carbamate in it. Did the moly show up in you OA results?

As I posted on page 9 of this thread, zinc was 650 ppm, and Phos was 550, after 3k miles. Other UOA's show similar levels.

The newer Deposit Shield UOA's show very similar amounts, while VOA's on the new stuff indicate that it starts out at about 850 for zinc and 750 for phos.

 

[bewilderedbeast]

Havoline is an excellent oil, and still priced better than many.
My UOA showed 313ppm of moly. Both the "older" SM version, and the newer "Deposit Shield" SM have been bringing in very excellent results.

 

[Ecomike]

As I previously said "Now I refer back to the original www.lnenginering.com web site (post #1 in this thread) that referenced test data showing 0.095 %" (sorry I had an error there it was percent, not PPM), 950 PPM "as the best MINIMUM ZDDP concentration to minimize cam and lifter wear for a 205 lbs pressure spring rate." So that sets 950 ppm. .095% Zn from the ZDDP as the minimum desirable concentration at the end of OCI.

We know that 1200 ppm of ZDDP has worked in the Sl formulation, or at least we think it has. I am extrapolating to the 950 ppm test data above as a reasonable point for an OCI in order to avoid unnecesary wear. That leaves 250 PPM consumed between OCIs.

As to your last question, the answer is reaction equilibrium. The formation of the active film is reaction rate equilibrium limited by the ZDDP concentration in the oil itself, as well as the film temperature, detergent concentration and surface metal activity which is increased my metal to metal contact.

Just LOOK at the wear data on the 200 lb pressure spring (same as a Jeep) in the www.nlengineering.com/oil.html post. It says:

"In a SAE paper titled "How Much ZDP is Enough?" from 2004, the resulting trend of decreasing phosphorus is as a direct result of observations that modern engines, with lower spring pressures and lighter vavletrain, including multiple intake and exhaust valves, seems to require only .03% Ph to prevent wear. It was further documented that by increasing to 180 lbs of spring pressure with a .03% ZDP resulted in 267 mil of wear where with .05% ZDP concentration tests resulted in 26 mil of wear. That same .05% oil with just 205 lbs of pressure resulted in 153 mil of wear, requiring .095% ZDP to reduce wear, resulting in just 16 mil. The ZDP requirements of a motor oil are directly proportional to valvetrain spring pressure. Most older SOHC and pushrod aircooled Porsche engines have significantly more pressure, as a stock street pushrod Porsche 356 or 912 engine exceeds these levels of spring pressure compared to the levels of pressure on modern engines, for which oils are tested for."

Do you not see the HUGE non linear wear rate versus spring pressure versus ZDDP concentration in that data?

Also it says: "0.12% is ideal for Zn and P levels as documented by the 1977 SAE Journal paper titled "Cam and Lifter Wear as Affected by Engine Oil ZDP Concentration and Type", which evaluated the performance of these oils in various fleets around the country over the span of many years."

Regarding your requirement that my reply not be "rhetoric recital ...rationale." that would take all the fun out of it!

Why would you think that starting off with 1200 ..with 1200 being "enough" and expecting 900 ppm to be left in suspension at the end of the OCI? This infers that you feel that 300 ppm is all that will be sacrificed in the entire OCI...

Surely you need to give me the rationale behind this assertion here. It surely doesn't add up. Not rhetoric recital ...rationale.

Why would less than 300 ppm of contact rubbing/microwelding prevention require 4 times that saturation to adequately maintain the protection layer.

 

[bewilderedbeast]

Do any of these articles, or you, consider the possibility that moly, boron, and/or other additives may very well be capable of doing what the zinc was supposed to be doing?

 

[Ecomike]

Do any of these articles, or you, consider the possibility that moly, boron, and/or other additives may very well be capable of doing what the zinc was supposed to be doing?

Yes they do. But none of them that I know of (no one has posted any data) have been adequetly field, time tested in the real world for several years like the older oils have been (no one has posted any data). Turns out Shell's new Rotella T, CJ-4, already on the store shelves, bearing the new API CJ-4/SM label, has not even passed the new API CJ-4/SM lab tests yet (see my earlier post today).

I just don't like the idea of them (oil companies) experimenting with my engine with out telling me the truth and me agreeing to the tests first.

I do a lot of experimental work myself, but I do it with the knowledge of what I am testing. I don't like being someone elses test mouse with out being told first and with out giving my approval first.

I also see no testing by EPA to pretest and approve the replacement additives to assure that they won't cause cat converters ECDS problems too. (Early Cat Death Syndrome, LOL). Of course the oil companies don't want to tell EPA what they are switching, replacing ZDDP with anyway. It will be another 10 years before we get that bad news.

 

[Ecomike]

Havoline is an excellent oil, and still priced better than many.
My UOA showed 313ppm of moly. Both the "older" SM version, and the newer "Deposit Shield" SM have been bringing in very excellent results.

That may be the highest moly number I have seen. How long have you been using it.