I put a stock replacement, standard volume Melling pump in it. Same as all my windsors.
Can too thick of oil be damaging?
- Thread starter RDY4WAR
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Originally Posted by RDY4WAR
I put a stock replacement, standard volume Melling pump in it. Same as all my windsors.
Excellent. I've seen far too many folks toss in an HV pump like they did in their SBC for whatever reason.
I put a stock replacement, standard volume Melling pump in it. Same as all my windsors.
Excellent. I've seen far too many folks toss in an HV pump like they did in their SBC for whatever reason.
Originally Posted by Whimsey
In my pre BITOG days I was under the impression that with oil "thickerer is the betterer" .
Whimsey
In my pre BITOG days I was under the impression that I should use what it said in the manual.
In my post-BITOG days I am under the impression that with oil "thickerer is the betterer" .
In my pre BITOG days I was under the impression that with oil "thickerer is the betterer" .
Whimsey
In my pre BITOG days I was under the impression that I should use what it said in the manual.
In my post-BITOG days I am under the impression that with oil "thickerer is the betterer" .
20wts may not be as readily available in other countries where they specify 30wts because they don't have CAFE there and the old adage thicker is better drives consumers to leave 20wt's on the shelf if there were there.
A UOA is the best way to tell what your engine does best on given your driving style, fuel usage, engine setup, oil and filter used. It's a complex situation and there is no blanket that says 30's 40's or 50 weight oils are better because they are thicker.
Do baselines, modify a variable (eg: Change the weight of the oil) and re-test. Then make a decision based on the data. NOT based on a "Feeling" based on what the data says.
A UOA is the best way to tell what your engine does best on given your driving style, fuel usage, engine setup, oil and filter used. It's a complex situation and there is no blanket that says 30's 40's or 50 weight oils are better because they are thicker.
Do baselines, modify a variable (eg: Change the weight of the oil) and re-test. Then make a decision based on the data. NOT based on a "Feeling" based on what the data says.
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Originally Posted by StevieC
20wts may not be as readily available in other countries where they specify 30wts because they don't have CAFE there and the old adage thicker is better drives consumers to leave 20wt's on the shelf if there were there.
If the grade were specifically for longevity, it would be there...they can ship a car to a country but not the oil specifically specified for it ???
Your logic is circular...the oil's not there, so the specify 30...and the customers leave the thinner oil on the shelves...which is it ?
I can get two brands of 0W16, a handful of 0W20s, and a few 5W20s in a five minute drive (see the pics I posted last weekend)...but GM STILL specifiy Dexos 2 oils with greater than 3.5HTHS for the Australian market, stating that thinner will void warranty.
20wts may not be as readily available in other countries where they specify 30wts because they don't have CAFE there and the old adage thicker is better drives consumers to leave 20wt's on the shelf if there were there.
If the grade were specifically for longevity, it would be there...they can ship a car to a country but not the oil specifically specified for it ???
Your logic is circular...the oil's not there, so the specify 30...and the customers leave the thinner oil on the shelves...which is it ?
I can get two brands of 0W16, a handful of 0W20s, and a few 5W20s in a five minute drive (see the pics I posted last weekend)...but GM STILL specifiy Dexos 2 oils with greater than 3.5HTHS for the Australian market, stating that thinner will void warranty.
If you read my earlier post I said they allow other weights but specify a 20 so they could care less if it's optimal or not and let the market decide what the shelves will stock.
Originally Posted by StevieC
If you read my earlier post I said they allow other weights but specify a 20 so they could care less if it's optimal or not and let the market decide what the shelves will stock.
But here they SPECIFY >3.5HTHS...where they SPECIFY Dexos 1 in CAFEville.
The oxen have been delivering Dexos1 to Oz just as long as they have been delivering Dexos 2, but for warranty, in Oz, GM SPECIFY (not allow, SPECIFY) Dexos 2.
You aren't reading my posts either by the looks of it.
If you read my earlier post I said they allow other weights but specify a 20 so they could care less if it's optimal or not and let the market decide what the shelves will stock.
But here they SPECIFY >3.5HTHS...where they SPECIFY Dexos 1 in CAFEville.
The oxen have been delivering Dexos1 to Oz just as long as they have been delivering Dexos 2, but for warranty, in Oz, GM SPECIFY (not allow, SPECIFY) Dexos 2.
You aren't reading my posts either by the looks of it.
Originally Posted by StevieC
Do baselines, modify a variable (eg: Change the weight of the oil) and re-test. Then make a decision based on the data. NOT based on a "Feeling" based on what the data says.
Probably not practical for me (and probably not economic for anyone) since I dunno how or if I'd get a UOA done here, probably wouldn't want to pay for one if I could, and I believe the significance of UOA metals data is questionable anyway.
There is, however, a "middle way", involving first principles and published data, which seem to indicate that "thicker is better" if cold-starts and maximum fuel economy arent of much interest. Thats not going to apply to everyone.
Do baselines, modify a variable (eg: Change the weight of the oil) and re-test. Then make a decision based on the data. NOT based on a "Feeling" based on what the data says.
Probably not practical for me (and probably not economic for anyone) since I dunno how or if I'd get a UOA done here, probably wouldn't want to pay for one if I could, and I believe the significance of UOA metals data is questionable anyway.
There is, however, a "middle way", involving first principles and published data, which seem to indicate that "thicker is better" if cold-starts and maximum fuel economy arent of much interest. Thats not going to apply to everyone.
Originally Posted by Ducked
Originally Posted by Whimsey
In my pre BITOG days I was under the impression that with oil "thickerer is the betterer" .
Whimsey
In my pre BITOG days I was under the impression that I should use what it said in the manual.
In my post-BITOG days I am under the impression that with oil "thickerer is the betterer" .
+1 .... for enhanced components protection.
Originally Posted by Whimsey
In my pre BITOG days I was under the impression that with oil "thickerer is the betterer" .
Whimsey
In my pre BITOG days I was under the impression that I should use what it said in the manual.
In my post-BITOG days I am under the impression that with oil "thickerer is the betterer" .
+1 .... for enhanced components protection.
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Originally Posted by RDY4WAR
Great info. Thanks for all of the replies so far.
I've torn down and built several engines. Earlier this year, I had to rebuild an engine I'd built a few years ago. It only had 18k miles on it. It was a 306ci SBF. I built it a little tight with .0020" main and .0018" rod bearing clearances. I recommended 10w-30. He didn't take my recommendation and ran VR1 20w-50 with Lucas oil stabilizer instead. He brought it back for a rebuild because he cut open his filter and found a lot of shavings. It still held 40 psi oil pressure at hot idle with no knocking. When I tore it down, 4 out of the 5 main bearings had spalling. Those same bearings had discoloration but no scuffing, uneven wear, or anything that would indicate metal to metal contact. The crank wasn't out of round. I put new bearings in, along with new seals and gaskets, and sent it back out. I took into consideration that he wasn't going to run anything but 20w-50 so I opened up the clearances to .0028" and .0026". I still am not sure what caused the bearings to spall but have been curious if the oil viscosity being too high for the clearances was a contributing factor.
IMHO, my take is :it's the out of true alignment of main bearing housing sets in this engine block (that requires rebuild), if you had not done so.
Oil discoloration < high heat < oil starvation < system centre line alignment , never mind crankshaft has true centre line.
Oil viscosity grade in use is likely not an issue.
Great info. Thanks for all of the replies so far.
I've torn down and built several engines. Earlier this year, I had to rebuild an engine I'd built a few years ago. It only had 18k miles on it. It was a 306ci SBF. I built it a little tight with .0020" main and .0018" rod bearing clearances. I recommended 10w-30. He didn't take my recommendation and ran VR1 20w-50 with Lucas oil stabilizer instead. He brought it back for a rebuild because he cut open his filter and found a lot of shavings. It still held 40 psi oil pressure at hot idle with no knocking. When I tore it down, 4 out of the 5 main bearings had spalling. Those same bearings had discoloration but no scuffing, uneven wear, or anything that would indicate metal to metal contact. The crank wasn't out of round. I put new bearings in, along with new seals and gaskets, and sent it back out. I took into consideration that he wasn't going to run anything but 20w-50 so I opened up the clearances to .0028" and .0026". I still am not sure what caused the bearings to spall but have been curious if the oil viscosity being too high for the clearances was a contributing factor.
IMHO, my take is :it's the out of true alignment of main bearing housing sets in this engine block (that requires rebuild), if you had not done so.
Oil discoloration < high heat < oil starvation < system centre line alignment , never mind crankshaft has true centre line.
Oil viscosity grade in use is likely not an issue.
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Originally Posted by RDY4WAR
What about on cold starts? On a 50 degree morning, a more viscous 20w-50 would take longer to circulate to the top of the engine than a less viscous 10w-30, correct? If that is correct, wouldn't that contribute to more long term wear?
Actually until you get below freezing the difference is negligible
What about on cold starts? On a 50 degree morning, a more viscous 20w-50 would take longer to circulate to the top of the engine than a less viscous 10w-30, correct? If that is correct, wouldn't that contribute to more long term wear?
Actually until you get below freezing the difference is negligible
The potential problems with using a high viscosity oil like a 20W50 are covered in detail above. These include poor cold startability (but only in very cold climes), less power & relatively poor fuel economy.
However it might be worth mentioning some of the very positive benefits of plopping a 'tight' Group I 20W50 in your engine...
- Greater Minimum Oil Film Thickness & higher HTHS. You will see this reflected in lower cam & lifter wear on most industry standard engine wear tests.
- Low Noack Volatility; as low as 3%-ish if you blend it properly.
- Low VII polymer loading (one of the lowest for the 'typical' viscosity grades). Put this together with that low Noack, and you'll deffo see this reflected in low piston deposits on tests like the Sequence IIIF/IIIG. You won't get late onset oil control ring stickage (& out of control oil loss) with a tight Group I 20W50!
- Very good oil solvency. As a result you'll get far less deposits on tests like the TEOST even though the oil will be inherently more prone to oxidation.
- it can be produced on fully depreciated plants that were built 50 years ago. As a consequence, it's dirt cheap to make which is why so much of the world is still wedded to it.
However it might be worth mentioning some of the very positive benefits of plopping a 'tight' Group I 20W50 in your engine...
- Greater Minimum Oil Film Thickness & higher HTHS. You will see this reflected in lower cam & lifter wear on most industry standard engine wear tests.
- Low Noack Volatility; as low as 3%-ish if you blend it properly.
- Low VII polymer loading (one of the lowest for the 'typical' viscosity grades). Put this together with that low Noack, and you'll deffo see this reflected in low piston deposits on tests like the Sequence IIIF/IIIG. You won't get late onset oil control ring stickage (& out of control oil loss) with a tight Group I 20W50!
- Very good oil solvency. As a result you'll get far less deposits on tests like the TEOST even though the oil will be inherently more prone to oxidation.
- it can be produced on fully depreciated plants that were built 50 years ago. As a consequence, it's dirt cheap to make which is why so much of the world is still wedded to it.
SonofJoe, that's good info.
How can someone identify a tight group I 20w-50 oil? Or a better question, what oils on the shelf currently employ that base oil?
How can someone identify a tight group I 20w-50 oil? Or a better question, what oils on the shelf currently employ that base oil?
Originally Posted by Shannow
Joe,
good info...so how would it go for things like turbocharger coking and the like ?
If you believe that Teost is a good predictor of turbo deposits (which is what Savant, the inventors of the test, would have you believe), then a tight 20W50 should be good on turbo coking.
However, I personally loathe all Teost tests. It produces results that correlate with nothing and as such, can be highly misleading. If you have a gasoline turbo engine, use a full synthetic. If you drive said car like a maniac, opt for PAO/Ester over Group III.
Joe,
good info...so how would it go for things like turbocharger coking and the like ?
If you believe that Teost is a good predictor of turbo deposits (which is what Savant, the inventors of the test, would have you believe), then a tight 20W50 should be good on turbo coking.
However, I personally loathe all Teost tests. It produces results that correlate with nothing and as such, can be highly misleading. If you have a gasoline turbo engine, use a full synthetic. If you drive said car like a maniac, opt for PAO/Ester over Group III.
Originally Posted by RDY4WAR
SonofJoe, that's good info.
How can someone identify a tight group I 20w-50 oil? Or a better question, what oils on the shelf currently employ that base oil?
I doubt very much if you can find any Group I engine oils in the US now, let alone a tight 20W50. The 20W50s you can buy will be all Group II and pretty sloppily blended. As such you lose any advantages of oil solvency, Noack & polymer loading.
The other thing that surprised me, when I looked at the price of VR1 20W50 here in the UK, was how extortionately expensive it is! The profit margins on this stuff probably dwarf what they make on their top tier oils. I guess 20W50 is a rarity now and suppliers can charge what the market will bear.
I suspect I do know where you could easily get such an oil but you won't like the answer. The country is very hot and sandy and starts with the letter 'I'. Interestingly, when I last looked, said oils all contained additives produced by American companies. We live in a Topsy-Turvy world....
SonofJoe, that's good info.
How can someone identify a tight group I 20w-50 oil? Or a better question, what oils on the shelf currently employ that base oil?
I doubt very much if you can find any Group I engine oils in the US now, let alone a tight 20W50. The 20W50s you can buy will be all Group II and pretty sloppily blended. As such you lose any advantages of oil solvency, Noack & polymer loading.
The other thing that surprised me, when I looked at the price of VR1 20W50 here in the UK, was how extortionately expensive it is! The profit margins on this stuff probably dwarf what they make on their top tier oils. I guess 20W50 is a rarity now and suppliers can charge what the market will bear.
I suspect I do know where you could easily get such an oil but you won't like the answer. The country is very hot and sandy and starts with the letter 'I'. Interestingly, when I last looked, said oils all contained additives produced by American companies. We live in a Topsy-Turvy world....
wemay
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Enjoy your vehicles, pick a viscosity, or two or three from which ever manual you choose to adhere to from any county you deem appropriate and oci you're comfortable with.
Whether CAFE inspired for "efficiency" or thicker for "extra protection", your car/truck will make it to several 100k miles.
Now, becsuse a mfr recommends a different (higher or lower viscosity, depending on your point of view) grade in another country does not mean the grade recommended in your manual is incapable of protecting your car. Ambient temps, driving styles, oil change intervals, traffic, engine design, and warm fuzzies all have there place in your choice.
Whether CAFE inspired for "efficiency" or thicker for "extra protection", your car/truck will make it to several 100k miles.
Now, becsuse a mfr recommends a different (higher or lower viscosity, depending on your point of view) grade in another country does not mean the grade recommended in your manual is incapable of protecting your car. Ambient temps, driving styles, oil change intervals, traffic, engine design, and warm fuzzies all have there place in your choice.
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wemay, nice effort at thin statesmanship.
GM, speccing the same engines in the US for Dex 1, and Oz as Dex 2 tells you something about what the engineers really think for the two markets.
The OP asked would thick damage anything...the answer is no.
edit...unlike the other situation...
GM, speccing the same engines in the US for Dex 1, and Oz as Dex 2 tells you something about what the engineers really think for the two markets.
The OP asked would thick damage anything...the answer is no.
edit...unlike the other situation...
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