Originally Posted By: CATERHAM
Originally Posted By: Shannow
It's obvious that some people don't get the concept of Noack...it's not something that has anything to do with the temperature of the oil in the sump...absolutely nothing to do with sump temperature...oils don't "run cool enough" for Noack to be irrelevant no matter how the science "feels"
It's supposed to represent what happens to the oil that is left above the rings on the downstroke (the rings are hydrodynamically lubricated on the upstroke when the piston speeds up, so the oil has to be the film that has been on the wall, exposed to the heat, oil pressure doesn't get it there).
Studies show that this oil is enriched in additives, so must be so as the oil evaporates off...smaller engines with greater BMEP are MORE likely to have cylinder temperatures that evaporate more.
Noack IS relevent, has nothing to do with sump temperatures and turbos
It never ceases to amaze me how much you like to spread miss information. The December issue of Lubes "N' Greases has an interesting article titled "Volatility: The Inside Story", for those that want to read it.
Some basic facts.
Limiting engine oil volatility has everything to do with controlling oil consumption and oil thickening as a result.
A couple of quotes from the paper:
"The question was, how to maintain healthy engine oil viscosity when vapor losses kept eroding the oil in the sump?"
"Low temperature oil viscosity can suffer when vehicles operate under high-temperature conditions (which volatilize the light ends of the oil and lead to thickening)."
Originally Posted By: CATERHAM
The Noack spec' of an oil doesn"t concern me much as it has no effect that I can detect, besides no synthetic has a poor Noack.
It is important to the OEMs primarily for emission control reasons and therefore if the oil is on a recommended company list it's Noack is acceptable.
http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3431515/Re:_Castrol_0w40_vs_Mobil_1_0w#Post3431500
Guess that you DID read the links after accusing me of continually spreading misinformation...
Originally Posted By: Shannow
It's obvious that some people don't get the concept of Noack...it's not something that has anything to do with the temperature of the oil in the sump...absolutely nothing to do with sump temperature...oils don't "run cool enough" for Noack to be irrelevant no matter how the science "feels"
It's supposed to represent what happens to the oil that is left above the rings on the downstroke (the rings are hydrodynamically lubricated on the upstroke when the piston speeds up, so the oil has to be the film that has been on the wall, exposed to the heat, oil pressure doesn't get it there).
Studies show that this oil is enriched in additives, so must be so as the oil evaporates off...smaller engines with greater BMEP are MORE likely to have cylinder temperatures that evaporate more.
Noack IS relevent, has nothing to do with sump temperatures and turbos
It never ceases to amaze me how much you like to spread miss information. The December issue of Lubes "N' Greases has an interesting article titled "Volatility: The Inside Story", for those that want to read it.
Some basic facts.
Limiting engine oil volatility has everything to do with controlling oil consumption and oil thickening as a result.
A couple of quotes from the paper:
"The question was, how to maintain healthy engine oil viscosity when vapor losses kept eroding the oil in the sump?"
"Low temperature oil viscosity can suffer when vehicles operate under high-temperature conditions (which volatilize the light ends of the oil and lead to thickening)."
Originally Posted By: CATERHAM
The Noack spec' of an oil doesn"t concern me much as it has no effect that I can detect, besides no synthetic has a poor Noack.
It is important to the OEMs primarily for emission control reasons and therefore if the oil is on a recommended company list it's Noack is acceptable.
http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3431515/Re:_Castrol_0w40_vs_Mobil_1_0w#Post3431500
Guess that you DID read the links after accusing me of continually spreading misinformation...