1978 Ford Thunderbird 400 6.6L Rotella T6 5w-40 3.1k mi
- Thread starter Danimal1q2w3
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You added three quarts. As it was stated, adding the make up oil will make the report better than it actually is. Your engine probably needs atleast new valve seals. Make sure your PCV system is working properly. I wouldn't get too optimistic with the use of max life, you got a 43 year old engine and the valve seals got to be hard as a rock.
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I don’t see how adding oil could possibly dilute wear metal. Wouldn’t it just make them less concentrated and back to a normal concentration?
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Those were SWEET cars!! I wonder how a "classic car formula" oil in 10W-30, 10W-40, or 20W-50 would do? I would use a conventional oil also.
I don't know enough about older engines and UOA's to give you an opinion. But I am curious what type of MPG you are getting driving this thing. If I remember correctly you bought this car after it had been sitting a long time right? Pretty cool that you're actually driving it now.
It sat for like 5-6 years. I drive it often.
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dnewton3
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You sort-of answered your own question. Being "less concentrated" means diluted in a layman's explanation. At face value it seems easy. But it's a bit more complex than that ...
There's a few theories on this. And they are based on conditions we don't really have any conclusive study data for. Adding make-up oil in large quantities will certainly dilute a sump IF that sump were proportionally gaining volume. But, you're adding oil because the oil is going "out" and to keep the sump at a safe operational oil (constant) level, you have to "add" more oil (but the "volume" in the engine stays the "same" because the level is intact). The debate gets nuanced when we take about where that missing oil goes, and what does it take with it????? Does the oil which leaves drip on the ground? Does it get consumed in the combustion process? Does it evaporate with poor NOACK performance? And, when these are considered, does the oil leave behind the wear metals when it does leave on it's journey out of the engine?
It would also depend WHEN the UOA were taken, relative to the last known oil top-off. For example, when do you decide to take the UOA? Typically as some predetermined mileage mark (Xxxx miles). My old 6.6L Dmax engine spec'd 10 quarts. When the oil hit the "add" mark on the dipstick, it was 2 quarts "low". That would imply that it lost 20% of the volume in "normal" operation. So do I take the UOA at the 8-qrt level, or add 2 quarts and then take the UOA???? That is, after all, a 20% shift in volume, but both the "low" and "full" levels are deemed acceptable by the OEM. If there were 100 small particles of aluminum in the sump, the percent concentration would be altered if I add the oil before or after the UOA.
100 particles / 10 qrts = 10 particles per quart
100 particles / 8 qrts = 12.5 particles per quart (a 25% increase over the other method)
Heck, you can even debate the state of "what percent shift happens???"
If you presume that 10 qrts being "full" is the starting point, and you end at 8 quarts, you lost 20% volume.
But if you presume 8 quarts is the starting point, and you add 2 qrts to go up to the full mark, you added 25% volume.
It's a matter of where you start and which way you go, because you change the volume by the same magnitude UoM volume (2 qrts), but you shifted the volume by either 20% or 25% depending on where you start!
ICP UOA analysis gives us a typical "ppm" (parts per million) view. That is based on the known volume of the sample, but the concentration of the sample relative to the state of the sump when the sample is taken is an unknown. We know how the sample is diluted when it's in the lab sample cup, but we don't know about it's dilution when the oil was drawn from the engine.
Here's a few boring reads that might help regarding the different methods being discussed:
Calculate actual concentration of a metal from the ICP-MS result?
I have digested 200 mg of sample in HNO³ and H2O2 and diluted upto 25 ml. After analysis on ICP-MS the answer is 99 ppm of Mg. Now How to calculate the actual concentration of Mg in the actual sample?
www.researchgate.net
1.5: ICP-AES Analysis of Nanoparticles
ICP-AES is a spectral technique that is used to both determine the presence of metal analyte and the concentrations thereof. The ICP-AES method is introduced and a practical example is presented. …
chem.libretexts.org
When it comes to the typical engine oil UOA and top-off dilution, it's all theory and I've not seen any data from SAE or other studies which definitively proves or disproves one rationale over another.
Here on BITOG, there is no standardized criteria on when to take a UOA, and under what conditions. So that's just one of the many variables which are induced into "macro" data sets.
Dave.
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That is among the longest cars ever built. Compress each cylinder with air at TDC and with a spark plug hose adapter, remove the valve springs a pair at a time and replace the seals. That is the cheapest and easiest quick fix for oil consumption I know of. If it continues to gulp oil, machining/hard parts is in the engines future. That 400 cubes delivering about 100 horsepower at the wheels I imagine. 1978 not a stellar year for vehicles.
Excellent explanation.You sort-of answered your own question. Being "less concentrated" means diluted in a layman's explanation. At face value it seems easy. But it's a bit more complex than that ...
There's a few theories on this. And they are based on conditions we don't really have any conclusive study data for. Adding make-up oil in large quantities will certainly dilute a sump IF that sump were proportionally gaining volume. But, you're adding oil because the oil is going "out" and to keep the sump at a safe operational oil (constant) level, you have to "add" more oil (but the "volume" in the engine stays the "same" because the level is intact). The debate gets nuanced when we take about where that missing oil goes, and what does it take with it????? Does the oil which leaves drip on the ground? Does it get consumed in the combustion process? Does it evaporate with poor NOACK performance? And, when these are considered, does the oil leave behind the wear metals when it does leave on it's journey out of the engine?
It would also depend WHEN the UOA were taken, relative to the last known oil top-off. For example, when do you decide to take the UOA? Typically as some predetermined mileage mark (Xxxx miles). My old 6.6L Dmax engine spec'd 10 quarts. When the oil hit the "add" mark on the dipstick, it was 2 quarts "low". That would imply that it lost 20% of the volume in "normal" operation. So do I take the UOA at the 8-qrt level, or add 2 quarts and then take the UOA???? That is, after all, a 20% shift in volume, but both the "low" and "full" levels are deemed acceptable by the OEM. If there were 100 small particles of aluminum in the sump, the percent concentration would be altered if I add the oil before or after the UOA.
100 particles / 10 qrts = 10 particles per quart
100 particles / 8 qrts = 12.5 particles per quart (a 25% increase over the other method)
Heck, you can even debate the state of "what percent shift happens???"
If you presume that 10 qrts being "full" is the starting point, and you end at 8 quarts, you lost 20% volume.
But if you presume 8 quarts is the starting point, and you add 2 qrts to go up to the full mark, you added 25% volume.
It's a matter of where you start and which way you go, because you change the volume by the same magnitude UoM volume (2 qrts), but you shifted the volume by either 20% or 25% depending on where you start!
ICP UOA analysis gives us a typical "ppm" (parts per million) view. That is based on the known volume of the sample, but the concentration of the sample relative to the state of the sump when the sample is taken is an unknown. We know how the sample is diluted when it's in the lab sample cup, but we don't know about it's dilution when the oil was drawn from the engine.
Here's a few boring reads that might help regarding the different methods being discussed:
Calculate actual concentration of a metal from the ICP-MS result?
I have digested 200 mg of sample in HNO³ and H2O2 and diluted upto 25 ml. After analysis on ICP-MS the answer is 99 ppm of Mg. Now How to calculate the actual concentration of Mg in the actual sample?1.5: ICP-AES Analysis of Nanoparticles
ICP-AES is a spectral technique that is used to both determine the presence of metal analyte and the concentrations thereof. The ICP-AES method is introduced and a practical example is presented. …
When it comes to the typical engine oil UOA and top-off dilution, it's all theory and I've not seen any data from SAE or other studies which definitively proves or disproves one rationale over another.
Here on BITOG, there is no standardized criteria on when to take a UOA, and under what conditions. So that's just one of the many variables which are induced into "macro" data sets.
Dave.
The wear metals level is influenced (1) how the oil is being lost, and (2) whether the sump is full or low when the sample is taken.
Roger that. It will also be a great indication of the engine condition. Blow by the piston rings will be heard escaping into the crankcase. Poor valve sealing will be heard either through the intake/carb and/or exhaust. (intake or exhaust valve sealing).
Wow. What a reply. Gives you a lot to think about. lol.You sort-of answered your own question. Being "less concentrated" means diluted in a layman's explanation. At face value it seems easy. But it's a bit more complex than that ...
There's a few theories on this. And they are based on conditions we don't really have any conclusive study data for. Adding make-up oil in large quantities will certainly dilute a sump IF that sump were proportionally gaining volume. But, you're adding oil because the oil is going "out" and to keep the sump at a safe operational oil (constant) level, you have to "add" more oil (but the "volume" in the engine stays the "same" because the level is intact). The debate gets nuanced when we take about where that missing oil goes, and what does it take with it????? Does the oil which leaves drip on the ground? Does it get consumed in the combustion process? Does it evaporate with poor NOACK performance? And, when these are considered, does the oil leave behind the wear metals when it does leave on it's journey out of the engine?
It would also depend WHEN the UOA were taken, relative to the last known oil top-off. For example, when do you decide to take the UOA? Typically as some predetermined mileage mark (Xxxx miles). My old 6.6L Dmax engine spec'd 10 quarts. When the oil hit the "add" mark on the dipstick, it was 2 quarts "low". That would imply that it lost 20% of the volume in "normal" operation. So do I take the UOA at the 8-qrt level, or add 2 quarts and then take the UOA???? That is, after all, a 20% shift in volume, but both the "low" and "full" levels are deemed acceptable by the OEM. If there were 100 small particles of aluminum in the sump, the percent concentration would be altered if I add the oil before or after the UOA.
100 particles / 10 qrts = 10 particles per quart
100 particles / 8 qrts = 12.5 particles per quart (a 25% increase over the other method)
Heck, you can even debate the state of "what percent shift happens???"
If you presume that 10 qrts being "full" is the starting point, and you end at 8 quarts, you lost 20% volume.
But if you presume 8 quarts is the starting point, and you add 2 qrts to go up to the full mark, you added 25% volume.
It's a matter of where you start and which way you go, because you change the volume by the same magnitude UoM volume (2 qrts), but you shifted the volume by either 20% or 25% depending on where you start!
ICP UOA analysis gives us a typical "ppm" (parts per million) view. That is based on the known volume of the sample, but the concentration of the sample relative to the state of the sump when the sample is taken is an unknown. We know how the sample is diluted when it's in the lab sample cup, but we don't know about it's dilution when the oil was drawn from the engine.
Here's a few boring reads that might help regarding the different methods being discussed:
Calculate actual concentration of a metal from the ICP-MS result?
I have digested 200 mg of sample in HNO³ and H2O2 and diluted upto 25 ml. After analysis on ICP-MS the answer is 99 ppm of Mg. Now How to calculate the actual concentration of Mg in the actual sample?1.5: ICP-AES Analysis of Nanoparticles
ICP-AES is a spectral technique that is used to both determine the presence of metal analyte and the concentrations thereof. The ICP-AES method is introduced and a practical example is presented. …
When it comes to the typical engine oil UOA and top-off dilution, it's all theory and I've not seen any data from SAE or other studies which definitively proves or disproves one rationale over another.
Here on BITOG, there is no standardized criteria on when to take a UOA, and under what conditions. So that's just one of the many variables which are induced into "macro" data sets.
Dave.
About 18 feet. It’s great. Haha. I want to put a 460/c6 in eventually so it’s days are numbered
You will not get as good of results with Maxlife 5w30 as you did with Rotella. These old motors don't much care for the "resource conserving" stuff. Keep using the diesel oil in it.
I
I agree. I’m a thickie. Just an experiment. Might try Mobil xw40 HM
Btw with regards to your 460 plans, you can stroke the existing 400M to 434ci with a stroker (4.250) rotating assembly, and you'll have less weight on the nose that way. Big blocks are great for the drag strip but you'll have a better balanced street ride sticking with a small block.
Of course if you just wanted to drag a 460 out of the junkyard and freshen it up, that would obviously be a lot cheaper. But anyway.
Of course if you just wanted to drag a 460 out of the junkyard and freshen it up, that would obviously be a lot cheaper. But anyway.
Appreciate that. I’m probably one of the youngest guys on here. These engines are way older than me and I appreciate the insight
I don’t know how you managed to 3x the oil change interval, seeing your previous report.
I wouldn’t have been able to do it. I’d slowly creep 100 miles at a time. Hahaha
Probably just going to stick to 3kI don’t know how you managed to 3x the oil change interval, seeing your previous report.
I wouldn’t have been able to do it. I’d slowly creep 100 miles at a time. Hahaha
Good idea on any carburated engine.
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