OCI, not when but why?

KARNUT · December 6, 2022

When I had my Toyota they wanted to see you every 5K miles. But only changed the oil at 10. Basically they were charging 25$ for rotating your tires. And 40$ for oil changes. Usually the time you waited was the same. I told them their whole set up was screwy. Basically pay for tires twice through the cost of rotation. Discount tire does it for free. There’s really no logical thinking when it comes to automobiles. Me included.

Grumpy Bear · December 6, 2022

I have not had nearly the success with the mechanical that my father and his brothers had, but I do continue to have a record better than double that of Joe Average. Much of that has nothing to do with my ability.

Uncle Bob's million-mile flathead for example was the result of a time when moving the powertrain from one decade to the next was about as easy as buttering your bread. That motor was born in a 36 "C" cab, moved to 40 something pickup, into a series of 50 Fords then back to a 37-half ton. After accomplishing the million miles was moved to an engine stand where it became a generator driver and finally a running motor in the school engine lab. When he retired, it was discarded by the school running as well as it did the day he bought it.

Today the drive line is pretty much done when the body is done. OEMs got their way. Everything is disposable. Few things interchangeable.

I sell a car when it quits moving or I get such a silly offer rationality insist I sell. I've had a few quit moving before 200K. Wrecked one and had one burn down. A few rotted out to an unsafe condition. While Joe Average gets 1.2% over the 200K mark I'm closer to 95% including the wrecks and rot out. Of those I got over the 200K mark I sold to others who went on to drive them to the 300K mark. A few others over 250K before meeting a tree, pole or deer. Have a Honda right now over 238K that is wrestling with rot but not yet defeated. LOL.

Point is we all work against a stacked deck and yet, you can still beat the house if you care to. Just takes a different set of skills and dogged determination. My current projects, Dizzy and Pepper, are those I am honing my rust and rot prevention skills on. The drivelines are already in the bag. I continue to hone my operating skill with every mile.

Pepper has been exceptional. I've spent zero $$$$ in breakdown maintenance. About $300 in premature part failures. The remarkable money not spent on Pepper has come in the form of 'normal wear and tear' that has far exceeded the limits of normal.

Because the OEM tires were not installed by my mechanic I did pay for R&B and all said and done, yes, I paid for the tire 2X. HOWEVER, I got 3X the service life from them as rated against the factory tire warranty of 40K.

Brakes are going to go 250K or better at current wear rates. Part of that is driving style and highway miles but it is also constant attention to keeping slides free and greased. Keeping fluid changed.

Battery is soon to cross 8 years' service life. Battery Tender during lulls in driving. Most miles are highway so many fewer starts than Joe Average. Wipers last forever due to my OCD windshield service. Most of my service requires zero money and just constant attention to detail.

UAO is just a new tool in the box I'm learning to use and has already paid dividends.

Grumpy Bear · March 2, 2023

Wear

Page 3 of this tread I posted this graph showing were vs the TBN/AN relationship.

Here is an example of wear verses miles on unit.

Take Aways:

1.) It takes longer than one may think for a power cylinder to settle down in sheading iron as reported in your UOA.

2.) Wear materials 'build' in your sample with mileage and samples of different lengths must be "normalized" to a standard. This fellow chose 1,000 miles. In this fellows case at 50K miles is roughly 5 ppm/K so if his OCI is say 5 K then his UOA would be reporting 25 ppm Fe. Early on when this chart is showing 15 ppm/K his report on 5K OCI would have shown 75 ppm.

3.) This graph should impress on you the breadth of variations possible during a unit's history. A single point does not a trend make.

4.) Some of that swing is the operator and ambient conditions of operation. But in this case, it is also the use of different lubricants. This fellow has several graphs, some of them showing one products points' highlighted in red.

5) At some point this trend line will go flat and continue there until the unit expires.

Which I hope explains this last often posted graph.

This graph does not show 'rate' of wear, ppm, but rather 'absolute wear', inches/mm of bore increase for example and clarity. That is as Fe ppm/k is declining, the absolute wear, measurable dimension, is increasing.

6.) So the lower the Fe ppm/K, the longer the unit last. All other things equal, and they never are.

7.) Extending OCI past the first graph's wear slope is a false economy. No good comes of running TBN into the ground.

customboss · March 2, 2023

35 minutes ago, Grumpy Bear said:

Wear

Page 3 of this tread I posted this graph showing were vs the TBN/AN relationship.

Here is an example of wear verses miles on unit.

Take Aways:

1.) It takes longer than one may think for a power cylinder to settle down in sheading iron as reported in your UOA.

2.) Wear materials 'build' in your sample with mileage and samples of different lengths must be "normalized" to a standard. This fellow chose 1,000 miles. In this fellows case at 50K miles is roughly 5 ppm/K so if his OCI is say 5 K then his UOA would be reporting 25 ppm Fe. Early on when this chart is showing 15 ppm/K his report on 5K OCI would have shown 75 ppm.

3.) This graph should impress on you the breadth of variations possible during a unit's history. A single point does not a trend make.

4.) Some of that swing is the operator and ambient conditions of operation. But in this case, it is also the use of different lubricants. This fellow has several graphs, some of them showing one products points' highlighted in red.

5) At some point this trend line will go flat and continue there until the unit expires.

Which I hope explains this last often posted graph.

This graph does not show 'rate' of wear, ppm, but rather 'absolute wear', inches/mm of bore increase for example and clarity. That is as Fe ppm/k is declining, the absolute wear, measurable dimension, is increasing.

6.) So the lower the Fe ppm/K, the longer the unit last. All other things equal, and they never are.

7.) Extending OCI past the first graph's wear slope is a false economy. No good comes of running TBN into the ground.

Modern engine contact wear is rings (maybe), cam and crank. Most other large bearing components aren’t gonna show Fe. 30-40 years ago yes.

customboss · March 2, 2023

Analyze this liquidpiston......LOL

https://www.liquidpiston.com/

Grumpy Bear · March 2, 2023

2 hours ago, customboss said:

Modern engine contact wear is rings (maybe), cam and crank. Most other large bearing components aren’t gonna show Fe. 30-40 years ago yes.

I generally write/speak/discus in terms of the sealing surfaces of the power cylinder. Foremost of these isn't the ring. It's the bore and for gas SI motors they are not exceptionally hard nor alloyed. It doesn't live in a pressurized area like a rod bearing. Lubrication depending mostly on location in the bore the rings are. Boundary, barely mixed, boundary, rinse and repeat twice per revolution. Most early iron is from the bore. As is most continuation. It is the reference point of the post.

Cam and followers are alloy and hard. Unless the sample contains steel alloy metals as well, nickel, chrome......bore it is.

Grumpy Bear · March 23, 2023

Heat, Oxygen, Contamination & OCI

Things that destroy an oil and bring it to condemnation. The OLM 'advice' the truck provides considers these stable and foreseeable.

Heat is managed by expected loads and thermostats and oxygens access to the oil is controlled via the CCV/PCV fresh air side. Contamination is the tricky one. They must sneak pas the rings to make it to the crankcase.

So, question; how much blowby does GM use as the amount that allows your oil to survive the 7,500 mile PLUS OCI? Is it the amount design team use? 0.03 to 0.05% of fuel? Or perhaps the 0.36% of fuel they use to address ring issues under warranty? Both contribute MUCH different stresses on the oil.

I'll bet the former and not the latter. But hey, what do I know. Keep pushing that quart in 2K motor to the 7.5K OLM limit.

:idiot:

Grumpy Bear · March 26, 2023

Compare these two charts:

The difference is the effect of boiling frogs slowly. First chart is pre-multigrade when oils were straight cuts decades ago. Lighter cut got lighter and heavier cuts got heavier. Some just disappeared.

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The page below COSTCO Kirkland Signature 5W30.

Note the number of ways 100 C viscosity is measured.

100 C Nominal 10.91.

100 C LTHS 6.9

100 C Shear Stability 9.4.

This tells you something important about the VII package. It shears with use AND with shear rate. Low VI without dilution is not just possible, it's inevitable. It's also the most important specification, period.

Oils that do not contain VII do not shear down. That means all three viscosity measurements at 100 C will be the same.

Grumpy Bear · March 31, 2023

Well, this is Disturbing....

I'm looking at Blackstone reports for Pennzoil 0W40 and they are listing the grade "normal" range as 11.3-14.5 cSt. Look up a post. How about 12.5-16.3 cSt. Drilling down on this I find the "normal' value in the Blackstone report is what is "normal" for this product, not the SAE Grade. :wtf: Wait! What?....

If this isn't bad enough this particular oil is shearing down to a mid 30 grade in under 2500 miles and yes dilution is under a half percent.

This got me looking into the Valvoline Dura Blend 5W30 I just took out of Dizzy. 10.6 cSt in the bottle so TODAY a lower half 30 Grade but a few years back a basement 30 Grade (up a post, left chart). 2K miles and it's a 20 Grade. :banghead:

So let me see if I understand this correctly. I can't get the public to give up 30W so I will lower it's spec to a 20 and the sheep will do as I please thinking they are doing what they have always done? :idiot: I'll just lie them into submission.

Watch your 6 kids!

Edited March 31, 2023 by Grumpy Bear

Ubiquity · March 31, 2023

I must tell you, I have a lot of reading to do before I have a chance at understanding the oil properties posts you make.

Apparently I had still been stuck in the muck of ignorance after reading your motor oil report. On the first run through I read that Marty advises some individuals in this group who just so happen to have 6 children, that they'd better watch over them or the oil giants will get them. I had to rewind for a moment to realize you meant watching your 6 O'clock position (posterior).

Thanks for the unintended laugh that I had on myself. Now I can return to my fog of ignorance.

Grumpy Bear · March 31, 2023

4 hours ago, 2015regcablongbed said:

I must tell you, I have a lot of reading to do before I have a chance at understanding the oil properties posts you make.

Apparently I had still been stuck in the muck of ignorance after reading your motor oil report. On the first run through I read that Marty advises some individuals in this group who just so happen to have 6 children, that they'd better watch over them or the oil giants will get them. I had to rewind for a moment to realize you meant watching your 6 O'clock position (posterior).

Thanks for the unintended laugh that I had on myself. Now I can return to my fog of ignorance.

The hardest thing I do is make myself understood.

KARNUT · March 31, 2023

1 hour ago, Grumpy Bear said:

The hardest thing I do is make myself understood.

Seeing those charts make my eyes bleed. I picked up over the years what vehicles generally need more frequent maintenance. Like going to the doctor for my yearly blood work. The results come in. I’m comparing with the previous year’s on my chart. About the time I got myself worked up. The nurse calls and says you’re doing great for your age. You should probably cut back on…. to head off future problems. And I do. Much like changing oil more often in certain vehicles. To ward off future problems.

Grumpy Bear · April 1, 2023

10 hours ago, 2015regcablongbed said:

I have a lot of reading to do before I have a chance at understanding the oil properties posts you make.

If you have a question, ask. I'll try to answer it. PM works too.

Grumpy Bear · April 1, 2023

On 11/10/2022 at 8:50 PM, swathdiver said:

I know a little about oil. After thirty plus years of driving one observation is that after about 5,000 miles the oil is dead. There's little lubricity in it as you rub it between your fingers compared with new oil. You can literally feel the renewed pep in the engine right after an oil change. I've noticed this with conventional oils and synthetic oils in mostly the 10W30 and 5W30 range in my lifetime.

Circling back.... (I love the above observation by the way).

My father showed us boys this 'feel the oil' when we were knee high. A valid test IMHO.

The Importance of Lubricant Film Strength (machinerylubrication.com)

[quote from this link] Film strength can be described as the lubricant’s ability to lessen the effects of friction and control wear by means other than the film thickness. [end quote]

If you read this entire link, you will find that polarity is a huge part of lubricity and it a large part of film strength. Nearly all antiwear additives and 'oily' bases are polar materials.

When talking to my father this week about this 'feel' thing he mentioned it along with his comments on the oil consumption of the Flathead Ford. "Something leaves the oil". What he was referring to was 'slipperiness" Lubricity!

Taking a shower in soft water with a bar of Castle Soap (lye based) and it is slick feeling. Can't rinse it off. When the salt is depleted in the softener.... STICK. :crackup: "Something left the water (oil)".

It's a property of oil that is not tested and does not show up on any UOA I know of. And before someone says, "No but additives are and they are an indirect proxy". Well, yes and no. Showing up in the FTIR doesn't mean 'active'. Base and acid balance would be closer and yet when the oil 'feels' dry those numbers will still be well before the crossing point.

Question? Do you know what temperature it takes to activate the ZZDP/ZZTP additives? 180 C / 356 F.

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Just a good read with morning coffee.

Piston Rings, Oil & Cylinder Wall Finish - Engine Builder Magazine