Particulate Size

[WyrTwister]

I read some time back , that particles in the oil , smaller than a certain size , do not hurt anything . Instead of causing wear , they tend to polish . That is about all I remember . Does anyone know if this is true & if it is true , what size that might be ? Thanks , :-)

 

[Ducked]

Seems to be the topic of the week. I doubt that its true. Can you remember where you read it? I also doubt that polishing is wear-free. Dont see how it would work if it was. I'd guess if a particle was small enough to fit between surface asperities the wear it caused would be very low, but probably even then not zero. Recent Parallel Thread

 

[dlundblad]

Polishing is the removal of material.

 

[i_hate_autofraud]

Even if particles were small enough to fit between surface asperities, getting those particles there amounts to wear along the way! Polishing once is OK, but as oil circulates millions of times it becomes wear!

 

[kschachn]

Millions of times? Are you saying that the particles that are never captured by any filter (0.0000% efficiency) are the ones that do this polishing wear? All filters are going to capture particles down to a low level, but just at a low efficiency. My window sceeen at home traps 2 micron particles, just not very efficiently. The same is true for an oil filter per the graphs that were posted. I don’t see how all these damaging particles go through the filter 100 times much less a million.

 

[Ether]

Some related info in this thread,page 6 onwards https://bobistheoilguy.com/forums/ubbthreads.php/topics/4585323/1

 

[goodtimes]

https://www.bing.com/images/search?q=beilby+layer&qpvt=bielby+layer&FORM=IGRE It depends on what kind of microscope you use to inspect the polish. There is a smearing effect, forming of this bielby layer, in some cases. I remember an old guy from the Czech Republic who was a master in optical polishing taught me, years ago. Harsh teaching too, as today I still remember the word bielby. There is a difference between a Carl Zeiss polished lens by a master in Germany, essentially art, and a lens polished in China by merchants. In cars everything is machined or ground, so nothing is really highly optically polished. Silicon wafers for electronics are CMP polished to atomic smoothness with colloidal silica.

 

[SubieRubyRoo]

Bielby Layer

 

[i_hate_autofraud]

Originally Posted By: kschachn

Millions of times? Are you saying that the particles that are never captured by any filter (0.0000% efficiency) are the ones that do this polishing wear? All filters are going to capture particles down to a low level, but just at a low efficiency. My window sceeen at home traps 2 micron particles, just not very efficiently. The same is true for an oil filter per the graphs that were posted. I don’t see how all these damaging particles go through the filter 100 times much less a million.

When I cut open a spin-on filter that has 2 FilterMags on it, rinse with varsol to remove the oil and leave the caught metals, it sure looks like the filter media doesn't do a heck of a lot. Does it catch some? yeah, just not much, what's left could polish and wear as per the question in the first post. When a ran a guesstimate in my case, miles, ave speed, engine hours and GPM likely from the oil pump I came up with 400,000 passes of the oil thru the filter. Oil filter makers in research papers say a particle can be caught, but also may be released later in actual use and caught again, maybe.... the vast majority of particles under 10 microns will easily go thru 100 times +++ easy. Even on my old cars, never had a filter where there was significant solids piled against the pleats of the filter. Yeah, there will be 1 in a million engine and filter that does, but not mine yet.

 

[Ducked]

Originally Posted By: Ether

Some related info in this thread,page 6 onwards https://bobistheoilguy.com/forums/ubbthreads.php/topics/4585323/1

Yeh, that's where I got the ref. in the other recent thread I linked to, originally posted by Shannow. It gives an example of filtered oil with 10,671 particles/ml between 5 and 15 microns, and says most wear is caused by particles below 10 microns. It doesnt support any lower size limit for wear-causing particles.