Originally Posted By: m37charlie
Originally Posted By: dnewton3
Filters catch particulate that is large enough to be caught. It can be metals and combustion byproducts. Insolubles are typically soot and other related byproducts. Most full flow filters are reasonably effective at 15um and larger. The bigger the particulate, obviously the easier to catch. Some "insolubles" may be caught, some may not.
But I cannot find any clear reference between what Blackstone calls "insolubles" and what I'd accept as reliable data. I've seen UOAs with really high wear metals such as Fe and Cu, and yet have the insolubles at less than .5. These's no direct reference to show that wear metal ppm and insolubles go hand in hand. What really made me start to pay little heed to the "insolubles" rating is how UOAs with and without bypass filtration often have very similar insoluble levels. I completely agree that it's good to have low insolubles. I just have seen so many UOAs with different filter brands (full flow and also bypass) show insolubles all in the same range. Look over a bunch of UOA data, and you'll start to see what I mean.
What do you think about bypass centrifuges vs. bypass filters?
Charlie
Centrifuge filters do a much better job of pulling out ever smaller stuff, for sure. But they also perform best when at a steady state of fluid velocity.
There are times in an engine where the rpm will fluctuate greatly with the application. For a street driven delivery vehicle or daily driver, I don't see centrifuge filters being ideal. For OTR or stationary applications, I think they are probably unbeatable for their performance/cost ratio.
I would like to caution that is SUPPOSITION on my part; not facts I can prove. I don't have enough data in my study from centrifuge applications to make a fair "for sure" statement. Further, because few people ever get a PC with their UOA, it makes corelation of the two almost impossible. Still - I think my logic is good, but I'll be the first to admit I cannot prove it at this point; too little data collected.
However, the thing to keep in mind is that ANY bypass filter is likely to clean the fluid to a level down to where the discussion of performance differences between designs and brands is moot because they ALL filter well enough to more than complete the job. I've seen and participated in discussions where people argue the merits of one brand over another. Oil Guard vs Amsoil vs Filtration Solutions vs Gulf Cost vs centrifuge ... etc on and on. Franky, it simply does not matter because the all do such a good job that you oil will be so clean it does not make any practical difference as to which one you choose.