I've read quite a few threads on here about more frequent oil changes causing more wear due to the fresh oil washing away the anti-wear layer put in place by the old oil, but how realistic is this theory? I'm planning on 4K OCI's on the Roadmaster on conventional oil, and I'm considering it severe service due to mostly short trips and random intervals of idling. I'm considering possibly even doing 3-3.5K mile OCI's, as that's what I used to do. When I say realistic, I mean how likely is it that this theory of premature wear is something to consider when planning out my intervals. What say you?
How Realistic Is This Theory?
- Thread starter Red91
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I don't think that motor is really going to be hard on oil to be honest. Single cam, push rod, short timing chain, decent sized sump, and larger filter. The LO5 motor should be pre fast burn heads, and has limited output as well. This is a flat tappet motor though, so maybe some thought on going with a higher zinc / phosphorus add pack oil? Maybe something SM / SL rated? Maybe a good candidate for an HDEO?
As long as it is mechanically sound (good rings, ect) I would run that motor much further than 3k with the right oil.
As for the theory? I don't buy in myself. If it does manifest I don't think its enough to effect anything within the reasonable life of the motor. By which I mean, maybe it could manifest if it was run out to 500k+.
Excellent car, I love B body cars.
As long as it is mechanically sound (good rings, ect) I would run that motor much further than 3k with the right oil.
As for the theory? I don't buy in myself. If it does manifest I don't think its enough to effect anything within the reasonable life of the motor. By which I mean, maybe it could manifest if it was run out to 500k+.
Excellent car, I love B body cars.
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I believe the 5.7 in my car is a roller cam engine, but I could be wrong. I think '87 to '95 truck and van TBI V8's were flat tappet, and the car and station wagon TBI V8's were roller cam. At any rate, I'm running Delo 400 SAE 30. I'd like to change at least twice a year, and 4K will translate into that for me.
MolaKule
Staff member
Originally Posted By: Red91
I've read quite a few threads on here about more frequent oil changes causing more wear due to the fresh oil washing away the anti-wear layer put in place by the old oil, but how realistic is this theory?...What say you?
I don't think there is any real data to support that other than a few inferential comments from papers whose authors wanted some limelight as if they had discovered something new.
Consider this about an oil change:
1. fresh oil carries a new additive pack that replenishes the additive components (that have been degraded) including the detergent and Anti-Wear components,
2. replaces oxidization byproducts and the contaminants that were previously there.
I've read quite a few threads on here about more frequent oil changes causing more wear due to the fresh oil washing away the anti-wear layer put in place by the old oil, but how realistic is this theory?...What say you?
I don't think there is any real data to support that other than a few inferential comments from papers whose authors wanted some limelight as if they had discovered something new.
Consider this about an oil change:
1. fresh oil carries a new additive pack that replenishes the additive components (that have been degraded) including the detergent and Anti-Wear components,
2. replaces oxidization byproducts and the contaminants that were previously there.
Last edited:
Originally Posted By: Red91
I've read quite a few threads on here about more frequent oil changes causing more wear due to the fresh oil washing away the anti-wear layer put in place by the old oil, but how realistic is this theory?
That's a bunch of B+S from guys that don't change their own oil and are too cheap to hire their oil changed.
I've read quite a few threads on here about more frequent oil changes causing more wear due to the fresh oil washing away the anti-wear layer put in place by the old oil, but how realistic is this theory?
That's a bunch of B+S from guys that don't change their own oil and are too cheap to hire their oil changed.
Originally Posted By: Merkava_4
That's a bunch of B+S from guys that don't change their own oil and are too cheap to hire their oil changed.
+1
That's a bunch of B+S from guys that don't change their own oil and are too cheap to hire their oil changed.
+1
Originally Posted By: Red91
I believe the 5.7 in my car is a roller cam engine, but I could be wrong. I think '87 to '95 truck and van TBI V8's were flat tappet, and the car and station wagon TBI V8's were roller cam. At any rate, I'm running Delo 400 SAE 30. I'd like to change at least twice a year, and 4K will translate into that for me.
It looks like 92 and 93 did indeed have the LO5 engine which seems to be flat tappet. I like your oil choice myself for that motor. If you are only doing it twice a year I'd leave that be. I will move a change right before it gets really cold in the winter myself, so I understand the convenience of doing them not just by mikage.
I believe the 5.7 in my car is a roller cam engine, but I could be wrong. I think '87 to '95 truck and van TBI V8's were flat tappet, and the car and station wagon TBI V8's were roller cam. At any rate, I'm running Delo 400 SAE 30. I'd like to change at least twice a year, and 4K will translate into that for me.
It looks like 92 and 93 did indeed have the LO5 engine which seems to be flat tappet. I like your oil choice myself for that motor. If you are only doing it twice a year I'd leave that be. I will move a change right before it gets really cold in the winter myself, so I understand the convenience of doing them not just by mikage.
I really don't subscribe to it, but the idea intrigues me. I like having clean oil in the engine though, and I'll probably never adopt a 10K mile OCI. 3-4K have always served me well.
The TBI small blocks are probably my favorite engines, and the one in my wagon is nice and torquey down low. Yeah, the Delo really appeals to me for older engines, it's got nice zinc and phosphorous levels and has a -17 degree F pour point. Pretty well the ideal oil for my situation.
There is a body of engineering evidence that says oil makes anti-wear (AW) compounds in that specific engine based on the metallurgy used, the heat and pressures available, etc. These compounds are "activated" from the additive package.
The goal is to have some of these locally formed AW compounds available at all times. So the consensus is to retain 10% of used motor oil when you change. That is usually accomplished by leaving the filter in place for a few weeks after an oil drop. The used oil will mix with the new and keep some AW functioning until the new oil has had a chance to form compounds too. Then change the filter and top up.
Obviously none of this would work if you switched brands and started with a new Add-Pak based on other chemistry... So depending on how long you want that motor to run (mechanically), you might consider staying with a reliable brand that can be bought at reasonable cost and used repeatedly.
In the long run, delaying a car or truck replacement by a few years, or an engine overhaul will offset the cost difference in oil by many many times over
The goal is to have some of these locally formed AW compounds available at all times. So the consensus is to retain 10% of used motor oil when you change. That is usually accomplished by leaving the filter in place for a few weeks after an oil drop. The used oil will mix with the new and keep some AW functioning until the new oil has had a chance to form compounds too. Then change the filter and top up.
Obviously none of this would work if you switched brands and started with a new Add-Pak based on other chemistry... So depending on how long you want that motor to run (mechanically), you might consider staying with a reliable brand that can be bought at reasonable cost and used repeatedly.
In the long run, delaying a car or truck replacement by a few years, or an engine overhaul will offset the cost difference in oil by many many times over
The L05 in my 1992 Roadmonster was a roller cam, I had to replace the timing chain and had a look at it.
From my memory: Cars (Camaro, Caprice, Roadmonster, Custom Cruiser) had roller cams.
The truck/van L05 (same RPO, inexplicably) had a flat tappet cam.
I think the OP had it right.
PS: I miss that car a lot. It finally left with 240K of hard Michigan miles on it.
From my memory: Cars (Camaro, Caprice, Roadmonster, Custom Cruiser) had roller cams.
The truck/van L05 (same RPO, inexplicably) had a flat tappet cam.
I think the OP had it right.
PS: I miss that car a lot. It finally left with 240K of hard Michigan miles on it.
Originally Posted By: BrocLuno
There is a body of engineering evidence that says............
Reference? Link?
There is a body of engineering evidence that says............
Reference? Link?
I drive mine almost every day. In fact, today is the first day in probably a month or more that it hasn't been driven. I love the wagons, they are just so dang handy.
Originally Posted By: volodymyr
Originally Posted By: Merkava_4
That's a bunch of B+S from guys that don't change their own oil and are too cheap to hire their oil changed.
+1
+2
Originally Posted By: Merkava_4
That's a bunch of B+S from guys that don't change their own oil and are too cheap to hire their oil changed.
+1
+2
MaxLife 10w30 or 40 changed every 4,000 mi. or 3 months (assuming driven every day - estimation on time frame) and rest easy.
Originally Posted By: OneEyeJack
Originally Posted By: BrocLuno
There is a body of engineering evidence that says............
Reference? Link?
http://www.bobistheoilguy.com/forums/ubb...r_W#Post4049815
And a few other papers indicate that USED oil forms tribofilms on virgin metal surfaces faster.
And other stuff that I've read indicate that the tribofilms can last for some tens of hours when run with additive free oil.
So I'm not so sure where the line in the middle is here, or if there IS a line in the middle.
My current routine is to change the filter every second oil change, and do the filter a couple of weeks after the oil, so that it gets whatever's floating around in the fresh oil (some of them are pretty dirty) out.
Originally Posted By: BrocLuno
There is a body of engineering evidence that says............
Reference? Link?
http://www.bobistheoilguy.com/forums/ubb...r_W#Post4049815
And a few other papers indicate that USED oil forms tribofilms on virgin metal surfaces faster.
And other stuff that I've read indicate that the tribofilms can last for some tens of hours when run with additive free oil.
So I'm not so sure where the line in the middle is here, or if there IS a line in the middle.
My current routine is to change the filter every second oil change, and do the filter a couple of weeks after the oil, so that it gets whatever's floating around in the fresh oil (some of them are pretty dirty) out.
Originally Posted By: MolaKule
Originally Posted By: Red91
I've read quite a few threads on here about more frequent oil changes causing more wear due to the fresh oil washing away the anti-wear layer put in place by the old oil, but how realistic is this theory?...What say you?
I don't think there is any real data to support that other than a few inferential comments from papers whose authors wanted some limelight as if they had discovered something new.
Consider this about an oil change:
1. fresh oil carries a new additive pack that replenishes the additive components (that have been degraded) including the detergent and Anti-Wear components,
2. replaces oxidization byproducts and the contaminants that were previously there.
IDK
Dave Newton showed pretty conclusively that wear rates were lower per thousand miles on longer drain intervals.
OTOH, I ran many engines for many thousands of miles on short 3-4K drains long before I even considered UOAs or wear rates. There is an old-school philosophy that an engine will last just about forever if given plenty of fresh, clean oil. Seems like common sense.
The data as presented by D. Newton don't really support that notion, though.
Originally Posted By: Red91
I've read quite a few threads on here about more frequent oil changes causing more wear due to the fresh oil washing away the anti-wear layer put in place by the old oil, but how realistic is this theory?...What say you?
I don't think there is any real data to support that other than a few inferential comments from papers whose authors wanted some limelight as if they had discovered something new.
Consider this about an oil change:
1. fresh oil carries a new additive pack that replenishes the additive components (that have been degraded) including the detergent and Anti-Wear components,
2. replaces oxidization byproducts and the contaminants that were previously there.
IDK
Dave Newton showed pretty conclusively that wear rates were lower per thousand miles on longer drain intervals.
OTOH, I ran many engines for many thousands of miles on short 3-4K drains long before I even considered UOAs or wear rates. There is an old-school philosophy that an engine will last just about forever if given plenty of fresh, clean oil. Seems like common sense.
The data as presented by D. Newton don't really support that notion, though.
Aren't UOAs are really supposed to be about determining whether or not the oil is still serviceable or needs to be changed? They are also helpful to discover if there is contamination from the coolant system or if theres a fuel system related problem as well. That's what I've read on here many times.
I am not trying to give you a hard time here.
It's not the end all and be all of determining the interior conditions of a motor. That's performed by a tear down and weighing parts and measuring specs to within 0.00x or even 0.000x.
I am not trying to give you a hard time here.
It's not the end all and be all of determining the interior conditions of a motor. That's performed by a tear down and weighing parts and measuring specs to within 0.00x or even 0.000x.
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Who cares? It doesn't matter. It's a $500 car.
Close thread.
Close thread.
Originally Posted By: fdcg27
Originally Posted By: MolaKule
Originally Posted By: Red91
I've read quite a few threads on here about more frequent oil changes causing more wear due to the fresh oil washing away the anti-wear layer put in place by the old oil, but how realistic is this theory?...What say you?
I don't think there is any real data to support that other than a few inferential comments from papers whose authors wanted some limelight as if they had discovered something new.
Consider this about an oil change:
1. fresh oil carries a new additive pack that replenishes the additive components (that have been degraded) including the detergent and Anti-Wear components,
2. replaces oxidization byproducts and the contaminants that were previously there.
IDK
Dave Newton showed pretty conclusively that wear rates were lower per thousand miles on longer drain intervals.
OTOH, I ran many engines for many thousands of miles on short 3-4K drains long before I even considered UOAs or wear rates. There is an old-school philosophy that an engine will last just about forever if given plenty of fresh, clean oil. Seems like common sense.
The data as presented by D. Newton don't really support that notion, though.
Dave Newton didn't prove anything. He has no data that was controlled for the variables discussed below. Of course he never returned to the thread for any discussion of how he had controlled those variables.
Quote:
Originally Posted By: dnewton3
I'm not inflating anything. My data analysis is fair and accurate.
I am open to any discussion based upon facts and credible study (not conjecture or theory) that would counter mine.
Let's start with your data. We'll deal with the SAE article in separate posts.
Your data is Blackstone UOA, correct?
Do you have VOA's for each of the data points you use? It's necessary to subtract any wear metals present in the virgin oils, as any present effect your results.
I've given the following alternate explanation for higher wear metals at lower mileage in the past. It's a valid phenomenon that may explain part or all of what you see in a simple UOA. The "blip" we see in UOAs can not be used to demonstrate this supposed phenomenon either. Carryover is an uncontrolled variable.
Let's take an engine with a 5 qt. sump with 10% carryover that produces a constant 10ppm Fe per 1000 miles, and a 10K OCI as an example. Draw a sample at 1 mile and at every 1K thereafter. This is what the data would look like:
1 mile 11 ppm = 11ppm/mile
1K miles 21 ppm = 0.0210 ppm/mile
2K miles 31 ppm = 0.0155 ppm/mile
3K miles 41ppm = 0.0137 ppm/mile
4K miles 51 ppm = 0.0128 ppm/mile
5K miles 61 ppm = 0.0122 ppm/mile
6K miles 71 ppm = 0.0118 ppm/mile
7K miles 81 ppm = 0.0116 ppm/mile
8K miles 91 ppm = 0.0114 ppm/mile
9K miles 101 ppm = 0.0112 ppm/mile
10K miles 111 ppm = 0.0111 ppm/mile
There you go, higher wear metals seen in shorter mileage UOAs explained by simple math, no extra wear required.
Have you determined the extent of this phenomenon for every engine and application in your data set and corrected for it? If not you can not say that the increased wear metals is from wear.
Have you done experiments to determine if the higher metals might be from fresh oil solving varnish and sludge an releasing precipitated wear metals back into the oil? Unless you have proof that this is not a factor, you can't claim the higher wear metals are from wear.
How are you distinguishing metals present from wear vs entering the oil by other mechanisms, such as corrosion? The first rule of analytical chemistry is that if you are going to analyze for iron, don't store the sample in an iron bottle.
The big elephant in the room is that UOA by ICP is not a proxy for wear. The limits of the instrumentation prevent it from being used as such. It is possible to have "high" wear metals and lower wear than an engine with "low" wear metals. What supporting proof do you have for each data point that is is a valid indicator of wear? An example would be ferrographic particle counts, or measurements of each engine correlating actual wear with the UOA data.
Now, let's talk about the size of those particles that make it into the plasma. You've probably read many times that ICP can see wear particles at about 5 microns. The labs will tell you this also. They are wrong.
The particle size is based on the aerodynamic diameter, not the actual diameter. An ICP is designed to have a hard cut off of 4.5-5.0 microns due to the fact that droplets larger than that destabilize the plasma. That's where the 5 micron figure comes from. The problem is that is the aerodynamic diameter and is based on a spherical droplet of water. Aerodynamic diameter is affected by density and shape. Metals have a higher density than water, therefore smaller particles are required to achieve the same aerodynamic diameter and be allowed to pass through to the plasma.
This is one of the many reasons why "wear metals" do not serve as a good indicator of wear. The ICP only sees a portion of "normal" wear and miss most if not all of the larger particles generated by abnormal and break-in wear. The other is that due to the different densities of the metals the instrument does not see them equally. Given an equal amount and distribution of particle sizes, the ICP could read 4X as much aluminum as lead due to the density difference between the two. An accurate measure of what is in the oil can only be made if the oil undergoes a digestion to put the metals in solution.
The first 5 pages of this presentation cover what I have talked about. The illustration at the top of page 5 shows the relationship visually. They use a material with a density of 4000 kg/m3 for illustration. Aluminum, depending on alloy has a density of about 2700-2800, copper 8940, iron/steel 7850, and lead 11340. Visualize the 4000 kg/m3 circles at half that size and that is roughly the relative size of an iron particle that an ICP can see vs the 4.5 micron water droplet.
Aerodynamic Diameter
Ed
_________________________
Never attribute to engineers that into which politicians, lawyers, accountants, and marketeers have poked their fingers.
Originally Posted By: MolaKule
Originally Posted By: Red91
I've read quite a few threads on here about more frequent oil changes causing more wear due to the fresh oil washing away the anti-wear layer put in place by the old oil, but how realistic is this theory?...What say you?
I don't think there is any real data to support that other than a few inferential comments from papers whose authors wanted some limelight as if they had discovered something new.
Consider this about an oil change:
1. fresh oil carries a new additive pack that replenishes the additive components (that have been degraded) including the detergent and Anti-Wear components,
2. replaces oxidization byproducts and the contaminants that were previously there.
IDK
Dave Newton showed pretty conclusively that wear rates were lower per thousand miles on longer drain intervals.
OTOH, I ran many engines for many thousands of miles on short 3-4K drains long before I even considered UOAs or wear rates. There is an old-school philosophy that an engine will last just about forever if given plenty of fresh, clean oil. Seems like common sense.
The data as presented by D. Newton don't really support that notion, though.
Dave Newton didn't prove anything. He has no data that was controlled for the variables discussed below. Of course he never returned to the thread for any discussion of how he had controlled those variables.
Quote:
Originally Posted By: dnewton3
I'm not inflating anything. My data analysis is fair and accurate.
I am open to any discussion based upon facts and credible study (not conjecture or theory) that would counter mine.
Let's start with your data. We'll deal with the SAE article in separate posts.
Your data is Blackstone UOA, correct?
Do you have VOA's for each of the data points you use? It's necessary to subtract any wear metals present in the virgin oils, as any present effect your results.
I've given the following alternate explanation for higher wear metals at lower mileage in the past. It's a valid phenomenon that may explain part or all of what you see in a simple UOA. The "blip" we see in UOAs can not be used to demonstrate this supposed phenomenon either. Carryover is an uncontrolled variable.
Let's take an engine with a 5 qt. sump with 10% carryover that produces a constant 10ppm Fe per 1000 miles, and a 10K OCI as an example. Draw a sample at 1 mile and at every 1K thereafter. This is what the data would look like:
1 mile 11 ppm = 11ppm/mile
1K miles 21 ppm = 0.0210 ppm/mile
2K miles 31 ppm = 0.0155 ppm/mile
3K miles 41ppm = 0.0137 ppm/mile
4K miles 51 ppm = 0.0128 ppm/mile
5K miles 61 ppm = 0.0122 ppm/mile
6K miles 71 ppm = 0.0118 ppm/mile
7K miles 81 ppm = 0.0116 ppm/mile
8K miles 91 ppm = 0.0114 ppm/mile
9K miles 101 ppm = 0.0112 ppm/mile
10K miles 111 ppm = 0.0111 ppm/mile
There you go, higher wear metals seen in shorter mileage UOAs explained by simple math, no extra wear required.
Have you determined the extent of this phenomenon for every engine and application in your data set and corrected for it? If not you can not say that the increased wear metals is from wear.
Have you done experiments to determine if the higher metals might be from fresh oil solving varnish and sludge an releasing precipitated wear metals back into the oil? Unless you have proof that this is not a factor, you can't claim the higher wear metals are from wear.
How are you distinguishing metals present from wear vs entering the oil by other mechanisms, such as corrosion? The first rule of analytical chemistry is that if you are going to analyze for iron, don't store the sample in an iron bottle.
The big elephant in the room is that UOA by ICP is not a proxy for wear. The limits of the instrumentation prevent it from being used as such. It is possible to have "high" wear metals and lower wear than an engine with "low" wear metals. What supporting proof do you have for each data point that is is a valid indicator of wear? An example would be ferrographic particle counts, or measurements of each engine correlating actual wear with the UOA data.
Now, let's talk about the size of those particles that make it into the plasma. You've probably read many times that ICP can see wear particles at about 5 microns. The labs will tell you this also. They are wrong.
The particle size is based on the aerodynamic diameter, not the actual diameter. An ICP is designed to have a hard cut off of 4.5-5.0 microns due to the fact that droplets larger than that destabilize the plasma. That's where the 5 micron figure comes from. The problem is that is the aerodynamic diameter and is based on a spherical droplet of water. Aerodynamic diameter is affected by density and shape. Metals have a higher density than water, therefore smaller particles are required to achieve the same aerodynamic diameter and be allowed to pass through to the plasma.
This is one of the many reasons why "wear metals" do not serve as a good indicator of wear. The ICP only sees a portion of "normal" wear and miss most if not all of the larger particles generated by abnormal and break-in wear. The other is that due to the different densities of the metals the instrument does not see them equally. Given an equal amount and distribution of particle sizes, the ICP could read 4X as much aluminum as lead due to the density difference between the two. An accurate measure of what is in the oil can only be made if the oil undergoes a digestion to put the metals in solution.
The first 5 pages of this presentation cover what I have talked about. The illustration at the top of page 5 shows the relationship visually. They use a material with a density of 4000 kg/m3 for illustration. Aluminum, depending on alloy has a density of about 2700-2800, copper 8940, iron/steel 7850, and lead 11340. Visualize the 4000 kg/m3 circles at half that size and that is roughly the relative size of an iron particle that an ICP can see vs the 4.5 micron water droplet.
Aerodynamic Diameter
Ed
_________________________
Never attribute to engineers that into which politicians, lawyers, accountants, and marketeers have poked their fingers.
- Status
