ISO 100 oil with various basestocks
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cool pictures looks like GPI and a ESTER is the hot setup.
bruce
bruce
tho were this all 100% base stock only? blended to ISO 100?
try again with a small amount of AO 0.5% of L-57.
bruce
try again with a small amount of AO 0.5% of L-57.
bruce
Hi Bruce,
All of these oils are ISO 100 and are fully formulated by their manufacturer as premium industrial oils (R&O), so they do have anti-oxidants. The results are typical of these base oils in this test, but do not necessarily coorelate to motor oils due to the high detergents in engine oils.
Tom
All of these oils are ISO 100 and are fully formulated by their manufacturer as premium industrial oils (R&O), so they do have anti-oxidants. The results are typical of these base oils in this test, but do not necessarily coorelate to motor oils due to the high detergents in engine oils.
Tom
hey tom how clean would a current hydrotreated Napthenic do?? soft carbon or none at all how about a PIB no carbon?
bruce
bruce
Hi Bruce,
We have not tested any hydrotreated naphthenics, but if they are severely hydrotreated I would imagine the rings would open and the soft carbon associated with naphthenics would be lost. Also we have not attempted to isolate PIBs, but some oils that contain them show dirtier than I would expect, so it's possible that PIB may contribute some varnish like most other polymeric additives.
Tom
We have not tested any hydrotreated naphthenics, but if they are severely hydrotreated I would imagine the rings would open and the soft carbon associated with naphthenics would be lost. Also we have not attempted to isolate PIBs, but some oils that contain them show dirtier than I would expect, so it's possible that PIB may contribute some varnish like most other polymeric additives.
Tom
Could this be the case of the lighter, more volatile elements of the group I burning/evaporating off, leaving less behind to get "cooked". Where as the more stable oils stay put and get cooked for longer periods of time? All oils will degrade if stressed enough.
The ester looks good, but since there are thousands of them out there, the type of ester must be known for this to be useful. I'm sure TomNJ could find one that would perform like the others.
The types/grades of the other base stocks would nice to know as well. They might be using top of the line ester with the others bottom barrel.
This is also an extreme test. These temps are nearly 3 times operating PCMO temps.
The ester looks good, but since there are thousands of them out there, the type of ester must be known for this to be useful. I'm sure TomNJ could find one that would perform like the others.
This is also an extreme test. These temps are nearly 3 times operating PCMO temps.
Hi Tempest,
The ester used here is a diester. We have esters that can do better, such as our advanced POEs, but these are designed for more severe applications, so using such an ester here would not be a fair comparison.
We have not found this test to correlate strongly to volatility but it does correlate well to oxidative stability and polarity, with polarity often the largest factor. This is why the Group I shows reasonably well as it has aromatic compounds that contribute to polarity and hence solubility. Oils that have good oxidative stability breakdown slower, and oils with good solubility (polarity) can dissolve and/or disperse the breakdown products - that is, they clean up their own mess.
All of the oils used here are premium examples of ISO 100 R&O oils, specifically air compressor oils, that were formulated and optimized by their manufacturer. We felt this would be more fair than putting the same additive package in each of the base oils as they may respond differently. In any case, this particular photo was intended to give a visual representation of how the various classes typically perform in this test and not to make a scientific comparison of specific lubricants. We have consistently seen Group III and PAO formulations give more deposits over the many years we have run this particular test.
You are correct that this test is very severe and the results say nothing about performance in motor oils. The test was designed for jet engine oils where it is quite useful, and the photo is generally used to show the cleanliness properties in high temperature applications that are prone to coking, such as turbine engines, oven chains, and reciprocating air compressors.
There are esters that will perform poorly in this test, such as vegetable oils and oleates, but the types of saturated synthetic esters generally used in high temperature applications all do better than the Group III and PAO formulations that we have seen. That said, I still believe Group IIIs and PAOs offer the best value as the main component in synthetic car engine oils since varnish and carbon deposits are rarely a problem, and pure ester could lead to some seal problems. For the real severe high temperature industrial and aviation applications where coking is a problem, 100% ester based oils are the way to go.
Tom
The ester used here is a diester. We have esters that can do better, such as our advanced POEs, but these are designed for more severe applications, so using such an ester here would not be a fair comparison.
We have not found this test to correlate strongly to volatility but it does correlate well to oxidative stability and polarity, with polarity often the largest factor. This is why the Group I shows reasonably well as it has aromatic compounds that contribute to polarity and hence solubility. Oils that have good oxidative stability breakdown slower, and oils with good solubility (polarity) can dissolve and/or disperse the breakdown products - that is, they clean up their own mess.
All of the oils used here are premium examples of ISO 100 R&O oils, specifically air compressor oils, that were formulated and optimized by their manufacturer. We felt this would be more fair than putting the same additive package in each of the base oils as they may respond differently. In any case, this particular photo was intended to give a visual representation of how the various classes typically perform in this test and not to make a scientific comparison of specific lubricants. We have consistently seen Group III and PAO formulations give more deposits over the many years we have run this particular test.
You are correct that this test is very severe and the results say nothing about performance in motor oils. The test was designed for jet engine oils where it is quite useful, and the photo is generally used to show the cleanliness properties in high temperature applications that are prone to coking, such as turbine engines, oven chains, and reciprocating air compressors.
There are esters that will perform poorly in this test, such as vegetable oils and oleates, but the types of saturated synthetic esters generally used in high temperature applications all do better than the Group III and PAO formulations that we have seen. That said, I still believe Group IIIs and PAOs offer the best value as the main component in synthetic car engine oils since varnish and carbon deposits are rarely a problem, and pure ester could lead to some seal problems. For the real severe high temperature industrial and aviation applications where coking is a problem, 100% ester based oils are the way to go.
Tom
Thanks for the info TomNJ...I always learn something from your posts. Glad you are on the board.
If I may pick your brain some more:
Then why is it that they (Grp I) do so poorly in IC engines? Is it because they are closed and have no where for the "dirt" to go? Is this test open?
It sounds like your company is responsible for this test. Can you give a discription of the test or do you have a link to one?
I can see why jet engines/turbines use POE and why this test would be for that. The original poster did not spec. what and who this test is for. Do reciprocating air compressors really get this hot? I would think they would seize long before this temp.
Thanks.
If I may pick your brain some more:
Then why is it that they (Grp I) do so poorly in IC engines? Is it because they are closed and have no where for the "dirt" to go? Is this test open?
It sounds like your company is responsible for this test. Can you give a discription of the test or do you have a link to one?
I can see why jet engines/turbines use POE and why this test would be for that. The original poster did not spec. what and who this test is for. Do reciprocating air compressors really get this hot? I would think they would seize long before this temp.
Thanks.
Hi Tempest,
The varnish/carbon deposit performance of Group I oils in car engines has more to do with the additive system (detergents and dispersants) then the base oil. Most Group I based motor oils have a minimal additive system. And if you are referring to sludge, that is formed via a low temperature mechanism.
This coking test is a proprietary rig developed by a major oil company many years ago, so I cannot give intimate details or photos. In general, a steel block (panel) is held in a glass housing at a slight downward angle. The panel is internally heated to 540F and the oil is dripped onto the panel near the top. As the oil runs down the panel it spreads out and drips off the tip, where it is collected and pumped back to the top of the panel. The glass housing is purged with water saturated air and the test typically runs for 20 hours for esters. When running oils based on mineral oils or PAOs, we abbreviate the test to 3-6 hours as these base oils will not survive the 20 hour test and the panels will go totally black with carbon.
Recip air compressors do not get up to 540F, but they are notorious for deposit build-up on the valves above the cylinders which can lead to reduced efficiencies and sometimes explosions. The deposits are formed from a thin film of oil (from misting) on the hot metal valves, exposed to concentrated oxygen (compressed air). For many years people used naphthenic base oils for the recips because they gave a softer, powdery deposit that was easier to clean. Today most recips use all ester based oils to eliminate the deposit problem.
This coking test was designed for jet engines, but it gives a good reading on an oil's tendency to form deposits when you have a thin film of oil on hot metal, so we use it for other applications as well that are prone to such deposits.
Tom
The varnish/carbon deposit performance of Group I oils in car engines has more to do with the additive system (detergents and dispersants) then the base oil. Most Group I based motor oils have a minimal additive system. And if you are referring to sludge, that is formed via a low temperature mechanism.
This coking test is a proprietary rig developed by a major oil company many years ago, so I cannot give intimate details or photos. In general, a steel block (panel) is held in a glass housing at a slight downward angle. The panel is internally heated to 540F and the oil is dripped onto the panel near the top. As the oil runs down the panel it spreads out and drips off the tip, where it is collected and pumped back to the top of the panel. The glass housing is purged with water saturated air and the test typically runs for 20 hours for esters. When running oils based on mineral oils or PAOs, we abbreviate the test to 3-6 hours as these base oils will not survive the 20 hour test and the panels will go totally black with carbon.
Recip air compressors do not get up to 540F, but they are notorious for deposit build-up on the valves above the cylinders which can lead to reduced efficiencies and sometimes explosions. The deposits are formed from a thin film of oil (from misting) on the hot metal valves, exposed to concentrated oxygen (compressed air). For many years people used naphthenic base oils for the recips because they gave a softer, powdery deposit that was easier to clean. Today most recips use all ester based oils to eliminate the deposit problem.
This coking test was designed for jet engines, but it gives a good reading on an oil's tendency to form deposits when you have a thin film of oil on hot metal, so we use it for other applications as well that are prone to such deposits.
Tom
Tom,
Are you privy to similar testing of blended bastocks, say 50% Ester and 50% PAO?
Thanks.
Are you privy to similar testing of blended bastocks, say 50% Ester and 50% PAO?
Thanks.
Hi 427,
We have not conducted a study of various ratios of esters and PAO as we do not use any PAOs in our formulations, but we have run numerous competitive industrial formulations over the years to help our customers see the difference. Many of these competitive oils were PAO/ester blends and the results were always somewhere between the pure ester and pure PAO results.
Tom
We have not conducted a study of various ratios of esters and PAO as we do not use any PAOs in our formulations, but we have run numerous competitive industrial formulations over the years to help our customers see the difference. Many of these competitive oils were PAO/ester blends and the results were always somewhere between the pure ester and pure PAO results.
Tom
That explains Bruce's question. I was wondering about that.
Would quality PAO based compressor oils (like Amsoil) be that far behind ester based fluids? And I assume the only place one would see a real difference is in large units with high duty cycles?
Thanks again for the information.
problem is the AIR enviroment that is hot that causes gunk in a compressor. Esters will leave no to small amount of carbon, a PAO will work if highly inhibited and NOT run at very high temps a ester is better tho some guys wix the 2 to control costs better.
bruce
bruce
Would Flash/Fire Point of a PAO be an indication of quality/servicability? As in higher is better? Less material burned, less ash to form?
Amsoil's (for example only) PAO's are ~275C Fire point and:
Opinions welcomed.
The Amsoil "Sirocco" ester oils are labeled as biodegradable. The DC ester oils are not. Is the DC oil most likely Phthalate based? Thanks.
Amsoil's (for example only) PAO's are ~275C Fire point and:
Opinions welcomed.
The Amsoil "Sirocco" ester oils are labeled as biodegradable. The DC ester oils are not. Is the DC oil most likely Phthalate based? Thanks.
How about a highly inhibited PAO and ester blend?
""tho some guys wix the 2 to control costs better."'
Thats what I said mix both PAO and ESTER with a good AO.
bruce
PAO/ester blends are used extensively in screw compressors where deposits are not a problem, but I am not aware of pure PAO based recip compressor oils. The low additive solubility of PAOs does not permit high levels on anti-oxidants - typically AO levels are fire points of the PAO is not a significant factor as the oil vapors do not condense on the valves. In fact higher viscosity PAOs tend to give more deposits in our coking test.
Adding ester to PAO improves deposits and allows more anti-oxidants, so this will improve their performance, but not to the level of full ester based recip oils. And since most ester recip oils are based on low cost phthalates, there is not a meaningful cost penalty for going all ester.
Tom
Adding ester to PAO improves deposits and allows more anti-oxidants, so this will improve their performance, but not to the level of full ester based recip oils. And since most ester recip oils are based on low cost phthalates, there is not a meaningful cost penalty for going all ester.
Tom
""low cost phthalates, there is not a meaningful cost penalty for going all ester.""
Tom I must be looking at the wrong suppliers any decent ester is 1.5 to 1.7 times the price of a PAO.
bruce
Tom I must be looking at the wrong suppliers any decent ester is 1.5 to 1.7 times the price of a PAO.
bruce
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