OCI, not when but why?

[diyer2]

I commented because I wanted to.

[Grumpy Bear]

12 hours ago, diyer2 said:

I commented because I wanted to.

 

53, what month. 

[Grumpy Bear]

Valvoline Restore and Protect. Did I post this before?

 

[diyer2]

Nov/05/1953

[Grumpy Bear]

3 hours ago, diyer2 said:

Nov/05/1953

 

Same year, 18 days earlier.  

[VicFirth]

On 3/7/2024 at 11:21 PM, Grumpy Bear said:

Valvoline Restore and Protect. Did I post this before?

 

 

I'd be interested to know what gives this oil it's cleaning ability and whether it's truly "novel" or just current technology tweaked in some fashion.  Valvoline isn't exactly what I'd consider a leading edge formulator.  But ya never know.   Who knows what these additive companies can develop.  

[customboss]

4 hours ago, VicFirth said:

 

I'd be interested to know what gives this oil it's cleaning ability and whether it's truly "novel" or just current technology tweaked in some fashion.  Valvoline isn't exactly what I'd consider a leading edge formulator.  But ya never know.   Who knows what these additive companies can develop.  

Restore was developed by Cummins R&D. Because of corporate relationships Valvoline was blender. 
Restore IP was owned by Cummins so Valvoline must have worked a deal with Cummins to market this new product to retail market and gasoline applications. 
If you want to really learn the cleaning mechanism you’ll need better testing than what you posted. 

[Grumpy Bear]

 

[Grumpy Bear]

Oil Consumption V OCI Study #1

 

 

When you run until you have to add a quart to bring it to full, you're missing part of the story. 

 

 

I have gone to great lengths to assure accurate measurements and repeated this many, many times. Perfecting technique and equipment as I went until I obtained acceptable repeatability. I was fooled many times early on by the particulars of Dizzy's oiling system. She fools me no more. 

 

Oil consumption is not steady state. Kind of important when warranty work is under consideration. There is a reason they use 'new oil' when they do this study. It consumes more slowly AND given the short number of miles the study is run over, a play in the OEMs favor indeed. But it can be useful in other ways as well. 

 

Is this due to fuel dilution? Perhaps. But I have repeated this pattern even when there was no measurable fuel in the oil.

It changes the slope but not the endpoint behavior.

 

Is it shear down? Perhaps. Same effect as dilution and it is mirrored in the consumption pattern behavior. Could it also be a combination. 

 

What is certain is that eventually it reaches a steady state condition affected only thereafter by load. 

 

On this run, the motor consumed 2 ounces of oil over the first 500 miles. 4 ounces in the 338 miles. Over the last 504 miles it consumed 15-1/2 ounces of oil. The last segment broken into three where the add was pretty much identical every check and adjust. 

 

 So, in the beginning it used about a quart in 8K miles and by the end a quart in 1,158 miles. Calculated by segment, not over all. 

 

In the graph then the blue line is 'over all'. Total miles by total add per segment. The orange is segment miles by segment add. The red line is the slope of the orange line. That little dip in both, a segment run in the rain in high wind at Interstate speed (load). 

 

Now stead state what is known it that if the consumption test were run for say:

 

500 miles the consumption would be a quart in 8K miles.

1,000 miles it would be about a quart in 2.8K miles.

Run for a 2.5K OCI it would be a quart in 1,500 miles. 

As a segment the steady state value a quart in 1,158 miles. 

 

So an oil change every 1K miles puts 28-1/2 ounces into the combustion chamber over 2.5K miles of service.

An oil change every 2.5K puts 1-2/3 quarts through the combustion chamber. 187% more with the longer OCI. 

Well that can't be good for the cats. 

 

It also isn't good for the oil or cleanliness. 

 

In motors that don't look like they use oil all you can say is "over the OCI length" chosen.

 

Oil and its behavior is altered by blowby. The older and more worn the motor that short it takes to condemn the oil to the same degree so:

 

OCI is less a function of miles or hours and more a function of ring seal. 

 

 

Edited March 11, 2024 by Grumpy Bear

[VicFirth]

I always found it interesting when oil consumption remains at zero for say 3-4k miles, then between 4k-5k it loses a quart.  Never quite fully understood why that happens.  

 

This was an older Honda known for having low tension rings.  

Edited March 11, 2024 by VicFirth

[customboss]

7 hours ago, Grumpy Bear said:

Oil Consumption V OCI Study #1

 

 

When you run until you have to add a quart to bring it to full, you're missing part of the story. 

 

 

I have gone to great lengths to assure accurate measurements and repeated this many, many times. Perfecting technique and equipment as I went until I obtained acceptable repeatability. I was fooled many times early on by the particulars of Dizzy's oiling system. She fools me no more. 

 

Oil consumption is not steady state. Kind of important when warranty work is under consideration. There is a reason they use 'new oil' when they do this study. It consumes more slowly AND given the short number of miles the study is run over, a play in the OEMs favor indeed. But it can be useful in other ways as well. 

 

Is this due to fuel dilution? Perhaps. But I have repeated this pattern even when there was no measurable fuel in the oil.

It changes the slope but not the endpoint behavior.

 

Is it shear down? Perhaps. Same effect as dilution and it is mirrored in the consumption pattern behavior. Could it also be a combination. 

 

What is certain is that eventually it reaches a steady state condition affected only thereafter by load. 

 

On this run, the motor consumed 2 ounces of oil over the first 500 miles. 4 ounces in the 338 miles. Over the last 504 miles it consumed 15-1/2 ounces of oil. The last segment broken into three where the add was pretty much identical every check and adjust. 

 

 So, in the beginning it used about a quart in 8K miles and by the end a quart in 1,158 miles. Calculated by segment, not over all. 

 

In the graph then the blue line is 'over all'. Total miles by total add per segment. The orange is segment miles by segment add. The red line is the slope of the orange line. That little dip in both, a segment run in the rain in high wind at Interstate speed (load). 

 

Now stead state what is known it that if the consumption test were run for say:

 

500 miles the consumption would be a quart in 8K miles.

1,000 miles it would be about a quart in 2.8K miles.

Run for a 2.5K OCI it would be a quart in 1,500 miles. 

As a segment the steady state value a quart in 1,158 miles. 

 

So an oil change every 1K miles puts 28-1/2 ounces into the combustion chamber over 2.5K miles of service.

An oil change every 2.5K puts 1-2/3 quarts through the combustion chamber. 187% more with the longer OCI. 

Well that can't be good for the cats. 

 

It also isn't good for the oil or cleanliness. 

 

In motors that don't look like they use oil all you can say is "over the OCI length" chosen.

 

Oil and its behavior is altered by blowby. The older and more worn the motor that short it takes to condemn the oil to the same degree so:

 

OCI is less a function of miles or hours and more a function of ring seal. 

 

 

And valve and valve guide seal. 
What I call the power cylinder. 
EGR cycle contributes greatly too.

 

Edited March 11, 2024 by customboss

[diyer2]

I have had a few vehicles that had what I call delayed oil use. After an oil change one wouldn't use oil until about 1500 miles. The other one about 2k miles.  

Both had 3k OCI's with synthetic oil.

As the oil got dirtier the more oil was used. 

[Grumpy Bear]

14 hours ago, customboss said:

And valve and valve guide seal. 
What I call the power cylinder. 
EGR cycle contributes greatly too.

 

 

Gas Engine Reliability: Understanding Engine Oil Consumption (powermag.com)

Written by:

 

—Thijs Schasfoort and Clinton Buhler are senior technical services advisors for Petro-Canada Lubricants.

 

Found this a few days ago. Some counter intuitive points. Let us know what you think. I think you will like this one. Ash caught my attention. Many things did. "Ring Buffering" was another one. I'd never seen this explained before. It was just interesting. 

 

 

Edited March 12, 2024 by Grumpy Bear

[customboss]

3 hours ago, Grumpy Bear said:

 

Gas Engine Reliability: Understanding Engine Oil Consumption (powermag.com)

Written by:

 

—Thijs Schasfoort and Clinton Buhler are senior technical services advisors for Petro-Canada Lubricants.

 

Found this a few days ago. Some counter intuitive points. Let us know what you think. I think you will like this one. Ash caught my attention. Many things did. "Ring Buffering" was another one. I'd never seen this explained before. It was just interesting. 

 

 

That link is for “stationary gas engines” of which the fuel is methane.

 

Keep that in mind.  Why the deposits formations are counterintuitive.

 

Natural gas is a very dirty fuel. Once the methane burns off the rest of the fuel leaves gross deposits that eat oil and cause piston deposits and valve recession and  torching of valves. Spark plugs deposits are also a very troublesome issue. OTR trucks running nat gas engines sometimes need 15000 mile plug changes. 

Ring buffering is a fact of power cylinder concerns. Once again MOFT is a critical element in the search of  a Goldy Locks idealizing of a desired DYNAMIC VIS desired. 

Our spark gasoline/ethanol engines do not see combustion chamber temps that nat gas engines do. 
 

Ash formation in these nat gas engines is gross. 
 

 

[Grumpy Bear]

 

2 hours ago, customboss said:

Ring buffering is a fact of power cylinder concerns. Once again MOFT is a critical element in the search of  a Goldy Locks idealizing of a desired DYNAMIC VIS desired.

 

Got ya on NG fuel. I was thinking broader terms. Mechanics of the processes. Fuel will certainly have a huge impact. 

 

I found this paragraph most interesting: 

 

[Quote] Oil film thickness varies over the piston stroke length. Mid-stroke the piston speed is high and the rings travel on the liner surface in a fully hydrodynamic regime. As the piston slows down and enters either turnaround zone, the hydrodynamic effect lessens and the piston rings start pressing themselves through the oil film. The buffering effect will prevent the rings from reaching the liner before the piston starts moving again and the rings re-enter the hydrodynamic regime. The minimum required oil film thickness is determined by the amount of buffering that is needed. In practice, a partly flooded lubrication regime provides sufficient buffering effect to avoid top dead center ring/liner wear and will help to improve combustion chamber sealing and to reduce inertial throw-off (reduce oil consumption). [End Quote]

 

When I see this on the thrust side, I think the MOFT isn't being met. 

 

 

 

Hone hatching has been 'polished' away. (Above)

 

Different from scoring a cylinder. 

Looks like a lock got loose