Noack evaporation, how it's determined

[wemay]

 

[AZjeff]

Thanks, about what you'd expect. Wonder if the oil is analyzed before and after to determine change in properties?

 

[wemay]

Good question

 

[GermanAutohaus]

Originally Posted By: AZjeff
Thanks, about what you'd expect. Wonder if the oil is analyzed before and after to determine change in properties?


The body performing the NOACK test may also take it upon themselves to test the oil in various ways after evaporation, but typically the only notable change is the viscosity as lighter ends (molecules) are lost. It's totally independent of what the ASTM D-5800 is testing though.

 

[benjy]

many say our oils do not get that hot, but i remember seeing info that shows it does in certain parts in an engine + diesels see even higher temps than typical gas engines + i suspect big motorcycle engines also see some extreme temps, not to mention the affects of shared oil supplies. oil changes are surely cheap insurance compared to engine repair or replacements!!!

 

[Shannow]

It's as hot as it gets in the ring belt of your engine, and studies have shown a definite change in the additive concentration as the lighter fractions leave...
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3372187/Oil_ring_belt_residence_time_a

NOACK standard and a Selby paper here...
https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4820020/Re:_Thin_cleans_better,_allows#Post4820020

There's another "competing" technology the TGA method that weighs the samples as they are heated.
http://www.perkinelmer.com/CMSResources/...lVolatility.pdf

 

[Garak]

With the latter one, one might be able to actually get a curve, then. Trying to get data on that might be another matter altogether.