Cold Start Thickness - Dr. Haas
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Originally Posted By: Art_Vandelay
Originally Posted By: BuickGN
The smaller spread in numbers, the less likely it is to shear.
I'm sure that is true. Except for the case of some 0w30 oils specifically GC. It is more shear stable than any 5w30 made. I wonder if that is just a consequence of very high PAO content?
ANY 5w30 eh?
Originally Posted By: BuickGN
The smaller spread in numbers, the less likely it is to shear.
I'm sure that is true. Except for the case of some 0w30 oils specifically GC. It is more shear stable than any 5w30 made. I wonder if that is just a consequence of very high PAO content?
ANY 5w30 eh?
Originally Posted By: Taylor
Originally Posted By: Art_Vandelay
Originally Posted By: BuickGN
The smaller spread in numbers, the less likely it is to shear.
I'm sure that is true. Except for the case of some 0w30 oils specifically GC. It is more shear stable than any 5w30 made. I wonder if that is just a consequence of very high PAO content?
ANY 5w30 eh?
I was under the impression that it was. Which 5w30 is more shear stable than GC?
Originally Posted By: Art_Vandelay
Originally Posted By: BuickGN
The smaller spread in numbers, the less likely it is to shear.
I'm sure that is true. Except for the case of some 0w30 oils specifically GC. It is more shear stable than any 5w30 made. I wonder if that is just a consequence of very high PAO content?
ANY 5w30 eh?
I was under the impression that it was. Which 5w30 is more shear stable than GC?
How did you arrive to this conculsion?
To answer your question, I don't know! For all I know it very well may be true. My point is that, that's a pretty bold statement.
There are a couple of variables that could make an oil shear stable, base stocks would be one. VII's would be another, but that may or may not be directly related to base stock. Oils do funny things, look at Mobil 1's 0w40 for ex. It shears to a 30w rather quickly, and hen seems to stabilize.
To answer your question, I don't know! For all I know it very well may be true. My point is that, that's a pretty bold statement.
There are a couple of variables that could make an oil shear stable, base stocks would be one. VII's would be another, but that may or may not be directly related to base stock. Oils do funny things, look at Mobil 1's 0w40 for ex. It shears to a 30w rather quickly, and hen seems to stabilize.
Depends on the oil, I would imagine most 0w-30's have a lower pour point. But you may find a SAE 30 that comes close.
I live in VA so I have never been on a quest for the oil with the lowest pour point. FOR ME there are other, more important factors when choosing an oil. However if I lived somewhere where it got down to -60 degrees C, this would be a rather important factor.
I live in VA so I have never been on a quest for the oil with the lowest pour point. FOR ME there are other, more important factors when choosing an oil. However if I lived somewhere where it got down to -60 degrees C, this would be a rather important factor.
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Originally Posted By: Taylor
Depends on the oil, I would imagine a 0w30 has a lower pour point. But you may find a SAE 30 that comes close.
Thanks. This can get confusing, seeing Dr. Haas's chart and how the 30Wt is so much further away from that "10" at 100C. This seems as clear as mud.
I look at pour point, HTHS and a few other things. Cold start is important to me since I spend a lot of time in some very cold places during the winter.
AD
Depends on the oil, I would imagine a 0w30 has a lower pour point. But you may find a SAE 30 that comes close.
Thanks. This can get confusing, seeing Dr. Haas's chart and how the 30Wt is so much further away from that "10" at 100C. This seems as clear as mud.
AD
Originally Posted By: Taylor
How did you arrive to this conculsion?
To answer your question, I don't know! For all I know it very well may be true. My point is that, that's a pretty bold statement.
I was going by many of the readings I've done on here, where 5w30 is claimed to shear down to a 20 weight. If you read the CAFE threads this is always mentioned. So I was using that perspective and comparing it to GC's reputation as a stay in grade, extremely robust oil. I don't think I've read a single UOA on GC where the oil sheared down to a 20 weight.
I still believe that what I said is correct. Yet, I am absolutely fine with being wrong. I enjoy the learning just as much either way.
How did you arrive to this conculsion?
To answer your question, I don't know! For all I know it very well may be true. My point is that, that's a pretty bold statement.
I was going by many of the readings I've done on here, where 5w30 is claimed to shear down to a 20 weight. If you read the CAFE threads this is always mentioned. So I was using that perspective and comparing it to GC's reputation as a stay in grade, extremely robust oil. I don't think I've read a single UOA on GC where the oil sheared down to a 20 weight.
I still believe that what I said is correct. Yet, I am absolutely fine with being wrong. I enjoy the learning just as much either way.
Originally Posted By: Art_Vandelay
Yet, I am absolutely fine with being wrong. I enjoy the learning just as much either way.
+1 A person is never too old or too young to learn. I enjoy learning and sharing, and have no problems admitting mistakes either.
AD
Yet, I am absolutely fine with being wrong. I enjoy the learning just as much either way.
+1 A person is never too old or too young to learn. I enjoy learning and sharing, and have no problems admitting mistakes either.
AD
The problem is you can go off of this magic number ten, because there is no magic number, no silver bullet, no end all be all! Every motor is different, even withen it's on family. And different motors like different additives, viscosities, base stocks, etc. What worka for one may not work for the other. IMO like most things in life it's about balance. There are pros and cons with eveything.
Originally Posted By: Art_Vandelay
Originally Posted By: Taylor
How did you arrive to this conculsion?
To answer your question, I don't know! For all I know it very well may be true. My point is that, that's a pretty bold statement.
I was going by many of the readings I've done on here, where 5w30 is claimed to shear down to a 20 weight. If you read the CAFE threads this is always mentioned. So I was using that perspective and comparing it to GC's reputation as a stay in grade, extremely robust oil. I don't think I've read a single UOA on GC where the oil sheared down to a 20 weight.
I still believe that what I said is correct. Yet, I am absolutely fine with being wrong. I enjoy the learning just as much either way.
One reason it may stay in it it's grade so well is the fact that it's on the thicker end of it's grade. Meaning it has a lot of room to shear before it becomes a 20w.
Originally Posted By: Taylor
How did you arrive to this conculsion?
To answer your question, I don't know! For all I know it very well may be true. My point is that, that's a pretty bold statement.
I was going by many of the readings I've done on here, where 5w30 is claimed to shear down to a 20 weight. If you read the CAFE threads this is always mentioned. So I was using that perspective and comparing it to GC's reputation as a stay in grade, extremely robust oil. I don't think I've read a single UOA on GC where the oil sheared down to a 20 weight.
I still believe that what I said is correct. Yet, I am absolutely fine with being wrong. I enjoy the learning just as much either way.
One reason it may stay in it it's grade so well is the fact that it's on the thicker end of it's grade. Meaning it has a lot of room to shear before it becomes a 20w.
Originally Posted By: ADFD1
Originally Posted By: Art_Vandelay
Yet, I am absolutely fine with being wrong. I enjoy the learning just as much either way.
+1 A person is never too old or too young to learn.
AD
Some people to develop a high level of immunity as they age.
Originally Posted By: Art_Vandelay
Yet, I am absolutely fine with being wrong. I enjoy the learning just as much either way.
+1 A person is never too old or too young to learn.
AD
Some people to develop a high level of immunity as they age.
Pressure is not flow!!
Someone mentioned the test we used to do on motors to test bearings, chunking up the distributor shaft with an electric drill
(thus spinning the oil pump) and looking at the crankshaft bearings with the pan off. Even with lots of pressure, virtually no oil flows through that .002 bearing clearance when:
the oil is cold and you have good bearings.
Now, according to the big GM/Mobil/others study that was published in the SAE journal around 1980, the cylinder walls are starved for oil for a long time after startup with thicker oils in cold temperatures. When hot the situation changes from "a drop of oil every once in a while" to a continous shower of oil.
That study was the forerunner of the switch from 10wXXX oils to 5Wxxx oils. Their test results showed that cylinder wall wear was clearly much less with 5wXX oils, then with 10Wxx oils during the first 3 miles of operation - and that the bearings themselves were uneffected either way.
Those old enough to have done a lot of machine shop work in the 70's will remember that Ford attempted to save money by eliminating the little "squirter" drill hole in the top side of the rods big end. That resulted in thousands of engines being rebuilt in the north by Ford, under warranty due to extreme cylinder wall wear and scoring. (many at about 35,000 miles) This problem did not occur in the south at all!!! Note that those engines would have had plenty of pressure, but little flow, with cold thick oil in wintertime. I personally witnessed a 460 CI Lincoln continental, a 200 CI maverick and a pair of 2300 CC Pintos, all paid for by Ford under warranty. (The undrilled rods were always replaced when doing warranty work)
And, enhancing my paycheck.......
As you can see, arguments that center around how fast the pressure comes up are meaninless. Only flow counts - for the cylinder walls.
Some motors, like BUICKGN's 3.8 get lots of flow from the rod bearings due to their tortured crankshaft design and GM I believe always recommended 10Wxx oils in them. And many Turbo models have additional oil sprayed up to cool the piston bottoms, perhaps Buick can give us additional information about the 3.8's peculiar oil requirements.
Someone mentioned the test we used to do on motors to test bearings, chunking up the distributor shaft with an electric drill
(thus spinning the oil pump) and looking at the crankshaft bearings with the pan off. Even with lots of pressure, virtually no oil flows through that .002 bearing clearance when:
the oil is cold and you have good bearings.
Now, according to the big GM/Mobil/others study that was published in the SAE journal around 1980, the cylinder walls are starved for oil for a long time after startup with thicker oils in cold temperatures. When hot the situation changes from "a drop of oil every once in a while" to a continous shower of oil.
That study was the forerunner of the switch from 10wXXX oils to 5Wxxx oils. Their test results showed that cylinder wall wear was clearly much less with 5wXX oils, then with 10Wxx oils during the first 3 miles of operation - and that the bearings themselves were uneffected either way.
Those old enough to have done a lot of machine shop work in the 70's will remember that Ford attempted to save money by eliminating the little "squirter" drill hole in the top side of the rods big end. That resulted in thousands of engines being rebuilt in the north by Ford, under warranty due to extreme cylinder wall wear and scoring. (many at about 35,000 miles) This problem did not occur in the south at all!!! Note that those engines would have had plenty of pressure, but little flow, with cold thick oil in wintertime. I personally witnessed a 460 CI Lincoln continental, a 200 CI maverick and a pair of 2300 CC Pintos, all paid for by Ford under warranty. (The undrilled rods were always replaced when doing warranty work)
And, enhancing my paycheck.......
As you can see, arguments that center around how fast the pressure comes up are meaninless. Only flow counts - for the cylinder walls.
Some motors, like BUICKGN's 3.8 get lots of flow from the rod bearings due to their tortured crankshaft design and GM I believe always recommended 10Wxx oils in them. And many Turbo models have additional oil sprayed up to cool the piston bottoms, perhaps Buick can give us additional information about the 3.8's peculiar oil requirements.
Originally Posted By: fsskier
Pressure is not flow!!
Someone mentioned the test we used to do on motors to test bearings, chunking up the distributor shaft with an electric drill
(thus spinning the oil pump) and looking at the crankshaft bearings with the pan off. Even with lots of pressure, virtually no oil flows through that .002 bearing clearance when:
the oil is cold and you have good bearings.
Why would it? The crank isn't moving. Oil doesn't flow THROUGH hydrodynamic bearings. It flows TO them.
Pressure is not flow!!
Someone mentioned the test we used to do on motors to test bearings, chunking up the distributor shaft with an electric drill
(thus spinning the oil pump) and looking at the crankshaft bearings with the pan off. Even with lots of pressure, virtually no oil flows through that .002 bearing clearance when:
the oil is cold and you have good bearings.
Why would it? The crank isn't moving. Oil doesn't flow THROUGH hydrodynamic bearings. It flows TO them.
Originally Posted By: fsskier
Pressure is not flow!!
Someone mentioned the test we used to do on motors to test bearings, chunking up the distributor shaft with an electric drill
(thus spinning the oil pump) and looking at the crankshaft bearings with the pan off. Even with lots of pressure, virtually no oil flows through that .002 bearing clearance when:
the oil is cold and you have good bearings.
Now, according to the big GM/Mobil/others study that was published in the SAE journal around 1980, the cylinder walls are starved for oil for a long time after startup with thicker oils in cold temperatures. When hot the situation changes from "a drop of oil every once in a while" to a continous shower of oil.
That study was the forerunner of the switch from 10wXXX oils to 5Wxxx oils. Their test results showed that cylinder wall wear was clearly much less with 5wXX oils, then with 10Wxx oils during the first 3 miles of operation - and that the bearings themselves were uneffected either way.
Those old enough to have done a lot of machine shop work in the 70's will remember that Ford attempted to save money by eliminating the little "squirter" drill hole in the top side of the rods big end. That resulted in thousands of engines being rebuilt in the north by Ford, under warranty due to extreme cylinder wall wear and scoring. (many at about 35,000 miles) This problem did not occur in the south at all!!! Note that those engines would have had plenty of pressure, but little flow, with cold thick oil in wintertime. I personally witnessed a 460 CI Lincoln continental, a 200 CI maverick and a pair of 2300 CC Pintos, all paid for by Ford under warranty. (The undrilled rods were always replaced when doing warranty work)
And, enhancing my paycheck.......
As you can see, arguments that center around how fast the pressure comes up are meaninless. Only flow counts - for the cylinder walls.
Some motors, like BUICKGN's 3.8 get lots of flow from the rod bearings due to their tortured crankshaft design and GM I believe always recommended 10Wxx oils in them. And many Turbo models have additional oil sprayed up to cool the piston bottoms, perhaps Buick can give us additional information about the 3.8's peculiar oil requirements.
Which is why I never bought into the idea of oil shooting out of pushrods when an engine was first started means that all is good with parts getting lubricated. Those bearings need thinner oil to get to them faster than thick cold oil.
AD
Pressure is not flow!!
Someone mentioned the test we used to do on motors to test bearings, chunking up the distributor shaft with an electric drill
(thus spinning the oil pump) and looking at the crankshaft bearings with the pan off. Even with lots of pressure, virtually no oil flows through that .002 bearing clearance when:
the oil is cold and you have good bearings.
Now, according to the big GM/Mobil/others study that was published in the SAE journal around 1980, the cylinder walls are starved for oil for a long time after startup with thicker oils in cold temperatures. When hot the situation changes from "a drop of oil every once in a while" to a continous shower of oil.
That study was the forerunner of the switch from 10wXXX oils to 5Wxxx oils. Their test results showed that cylinder wall wear was clearly much less with 5wXX oils, then with 10Wxx oils during the first 3 miles of operation - and that the bearings themselves were uneffected either way.
Those old enough to have done a lot of machine shop work in the 70's will remember that Ford attempted to save money by eliminating the little "squirter" drill hole in the top side of the rods big end. That resulted in thousands of engines being rebuilt in the north by Ford, under warranty due to extreme cylinder wall wear and scoring. (many at about 35,000 miles) This problem did not occur in the south at all!!! Note that those engines would have had plenty of pressure, but little flow, with cold thick oil in wintertime. I personally witnessed a 460 CI Lincoln continental, a 200 CI maverick and a pair of 2300 CC Pintos, all paid for by Ford under warranty. (The undrilled rods were always replaced when doing warranty work)
And, enhancing my paycheck.......
As you can see, arguments that center around how fast the pressure comes up are meaninless. Only flow counts - for the cylinder walls.
Some motors, like BUICKGN's 3.8 get lots of flow from the rod bearings due to their tortured crankshaft design and GM I believe always recommended 10Wxx oils in them. And many Turbo models have additional oil sprayed up to cool the piston bottoms, perhaps Buick can give us additional information about the 3.8's peculiar oil requirements.
Which is why I never bought into the idea of oil shooting out of pushrods when an engine was first started means that all is good with parts getting lubricated. Those bearings need thinner oil to get to them faster than thick cold oil.
AD
I think if you don't run the thinnest oil you can your engine will explode, because that's what I read on the internet.
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