6.7L Engine Design
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Thanks for this thread, and for the discussion & information, Paul. I'm surprised to hear 7% fuel as a tolerable level; is that number based on FTIR testing, or an extrapolation from a flash point number (such as what most UOAs provide)? If it's an extrapolation from flash point, would you base it on open-cup (like most UOA houses), or closed-cup flash point? In our monitoring program, we get both FTIR fuels concentration and closed-up flash point data. Our fuel dilution and flash point numbers are always significantly different from what most see in their UOAs, based on our different (better, IMO) testing systems, so that's why I'm curious.
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MZ5,
There are two primary test methods that are used. Note that I've tried to write this so that those unfamiliar will hopefully have a better understanding of these tests. The Fourier transform infrared (FTIR) gas chromatography or just infrared or IR test for short, tests for water and glycol content, fuel dilution, oxidation, nitration and soot index. For those not familiar with the Infrared analysis, it's the most widely accepted test method in the industry today to determine lube condition. The test in it's basic form looks for Contamination Oxidation, Sulfation, Nitration, Water, Antifreeze and Soot and degradation of the oil in general (detergents, etc.)
Then there's a 2nd test, the base metals trace test, derived from the normal wear debris from the various metallic components. These particles are the result of rotating or sliding component within the engine assembly (pistons, rings, bearings, crank, etc.) The ASTM D5185 globally standardized test is pretty much the benchmark criteria used in the industry also known as atomic emission spectroscopy. It looks for pretty much any of the base metals used today, aluminum, boron, barium, calcium, chromium, copper, iron, lead, zinc, etc. etc.
So between the Fourier transform infrared (FTIR) gas chromatography with mass selective detector (GCMS) and the Inductively coupled plasma (ICP) you now have a nice overall snapshot of all the data needed to evaluate oil condition. This can then be used as an indicator to determine a number of things such as how well a particular oil stands up for a given application or how well an engine assembly is wearing.
The important piece of information here is that each test is only a snapshot in time. For this data to have any useful meaning, you really need to have multiple test results to correlate the data over a period of time (compare test results from multiple oil changes). And yes, the initial oil change will almost always have the highest levels of trace metals due to the initial break-in period. Imho, the results of the first oil change, at least for trace metals should be omitted when the data is gathered from a mass produced engine. This is normal, and has little correlation value. However, in the event of catastrophic failure, oil analysis is crucial for root cause analysis.
There are also some control factors that need to be observed such as making sure the same oil type is being used, the same fuel is being used, etc. This will help to eliminate variability in the test results by uncontrolled outside factors. This can have a significant impact on the test results and potentially lead to incorrect conclusions. It's also helpful during the testing process if there's a sample of the original unused oil. This helps determine a baseline of the oils original properties in relation to the used oil.
Now having said all that, you might be interested to know that most powertrain OEM developers rely on external 3rd party experts to perform these oil tests. Companies like Southwest Research Inst. design and develop comprehensive lab environments on a large scale for the sole purpose of providing unbiased reliable test data using latest measurement technologies. They provide this for the automotive, airline (turbines), military and pretty much any industry that uses lube oils.
Hope this helps!
-Paul
There are two primary test methods that are used. Note that I've tried to write this so that those unfamiliar will hopefully have a better understanding of these tests. The Fourier transform infrared (FTIR) gas chromatography or just infrared or IR test for short, tests for water and glycol content, fuel dilution, oxidation, nitration and soot index. For those not familiar with the Infrared analysis, it's the most widely accepted test method in the industry today to determine lube condition. The test in it's basic form looks for Contamination Oxidation, Sulfation, Nitration, Water, Antifreeze and Soot and degradation of the oil in general (detergents, etc.)
Then there's a 2nd test, the base metals trace test, derived from the normal wear debris from the various metallic components. These particles are the result of rotating or sliding component within the engine assembly (pistons, rings, bearings, crank, etc.) The ASTM D5185 globally standardized test is pretty much the benchmark criteria used in the industry also known as atomic emission spectroscopy. It looks for pretty much any of the base metals used today, aluminum, boron, barium, calcium, chromium, copper, iron, lead, zinc, etc. etc.
So between the Fourier transform infrared (FTIR) gas chromatography with mass selective detector (GCMS) and the Inductively coupled plasma (ICP) you now have a nice overall snapshot of all the data needed to evaluate oil condition. This can then be used as an indicator to determine a number of things such as how well a particular oil stands up for a given application or how well an engine assembly is wearing.
The important piece of information here is that each test is only a snapshot in time. For this data to have any useful meaning, you really need to have multiple test results to correlate the data over a period of time (compare test results from multiple oil changes). And yes, the initial oil change will almost always have the highest levels of trace metals due to the initial break-in period. Imho, the results of the first oil change, at least for trace metals should be omitted when the data is gathered from a mass produced engine. This is normal, and has little correlation value. However, in the event of catastrophic failure, oil analysis is crucial for root cause analysis.
There are also some control factors that need to be observed such as making sure the same oil type is being used, the same fuel is being used, etc. This will help to eliminate variability in the test results by uncontrolled outside factors. This can have a significant impact on the test results and potentially lead to incorrect conclusions. It's also helpful during the testing process if there's a sample of the original unused oil. This helps determine a baseline of the oils original properties in relation to the used oil.
Now having said all that, you might be interested to know that most powertrain OEM developers rely on external 3rd party experts to perform these oil tests. Companies like Southwest Research Inst. design and develop comprehensive lab environments on a large scale for the sole purpose of providing unbiased reliable test data using latest measurement technologies. They provide this for the automotive, airline (turbines), military and pretty much any industry that uses lube oils.
Hope this helps!
-Paul
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I have had my new 2011 F250 Diesel for 3 months and I have 12,000 miles on it already. I love the truck. My question is why does the engine compartment look like it was designed by a committee. Why is the dipstick in the back of the engine so that you have to reach over a really hot engine to check it. Why is the oil filler in the back as well. Is there a particular reason? If not I would sure put in my two cents to have it moved back to the front of the engine to make it easier. Also why is it that you have to take the grill off to change a light bulb. I have had three chevy's in the last 10 years and they were so easy to service. This new Ford is the best looking truck on the market but could sure use some common sense when it comes to servicing.
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Dbags
I do not know if you have seen all of Paul's posts regarding the 6.7 design. He actually covered the dipstick location in another post. He commented about how that was a very difficult item to engineer given the layout of the engine. Surely the oil fill situation is similar. He also has addressed the ease of serviceability issue from the last 2 engines.
Regards
I do not know if you have seen all of Paul's posts regarding the 6.7 design. He actually covered the dipstick location in another post. He commented about how that was a very difficult item to engineer given the layout of the engine. Surely the oil fill situation is similar. He also has addressed the ease of serviceability issue from the last 2 engines.
Regards
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