MolaKule
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Article on Varnish
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Are they saying that changing brands of API cert oil that cause mixing of base stocks and additives can lead to increased varnish?
MolaKule
Staff member
"Although API Group II and III formulated lubricants outperform API Group I (solvent refined) oils in virtually all categories, the research to date is inconclusive concerning varnish prevention."
The article is a good addition, thanks.
aehaas
aehaas
depends where the varnish is and how much there is.
I just started using a blended oil (Schaeffer's 7000 10W30) in one of my vehicles. It's 80% Grp II+/20% PAO. This article indicates it just may be a "varnish monster", as opposed to the full synthetics or Grp II+ oils. Has anyone noticed increased varnish using the Schaeffer's 7000?
This may explain the demise of many older motors...they were ran with Grp I oils for most of their lifetimes...when oil formulations changed to GrpII and III the propensity for varnish and sludge were increased...could be a reason oil manufacturers are using additives we have not seen before to combat this...makes one wonder if that old tractor really needs modern oil...or if those "vintage" oils have some merit...
Well this article certainly provides some evidence that mix and match oil formulations by us at home are NOT exactly the best thing in the world if one is trying to control this problem. Guess this also means that me constantly changing oils' brands is NOT a good way to prevent it either.
Looks like I'm still doing it wrong as well.
The point thought that I liked reading was about just how much further we are pushing engines to do the job. Back in the "old days", if an engine was able to produce 50 bhp per liter, that was considered "high output". Now, that is almost a drop in the bucket with most of the multi-valve, turbo charging, and supercharging going on.
Looks like I'm still doing it wrong as well.
The point thought that I liked reading was about just how much further we are pushing engines to do the job. Back in the "old days", if an engine was able to produce 50 bhp per liter, that was considered "high output". Now, that is almost a drop in the bucket with most of the multi-valve, turbo charging, and supercharging going on.
I noticed that they were offering a solution to the varnish problem which includes removal of submicronic particles. Sounds like some sort of bypass or centrifuge spinner to me. I remember once seeing a test done by Amsoil on NYC cab fleet and remember that the engines that were run 60k miles on the Amsoil with a bypass oil filter were cleaner in some areas that those using normal 3000 mile oil changes on regular oil. Seemed pretty unbelievable to me. I wonder that if adding the LC every 1000 miles helps to reduce this varnish formation. I'm not completely convinced it removes a lot of varnish, though.
Read an article ,form an opinion on something we really have no clue on ,and have a new thing to worry about something that is not worth worrying about.
I do routine and normal maintenance, and am very much overkill on the OCI intervals that I use...I'm not worried at all. Just anal...
This article'c contents have some applications to motor oil (degradation mechanisms and detection methods) but it's directed at gas turbines and there are some important differences. Additized Group 1 can make good gas turbine oil and there have been varnish problems when a Group 2 based oil replaces the formerly used Group 1 based oil, because the former has lower solvency (ability to keep the varnish in suspension). But don't extend this fact to motor oils. A purely Group 1 based motor oil would suck for deposit prevention in typical drain intervals.
Gotcha JAG, thanks for the clear up on that one...forgot about as group increases/solvency decreases.
I guess even though a turbine spins a whole lot faster than a piston engine ever thought of, there is less shear stress, right? So a lower group basestock would be more than adequate to reduce the varnish build up.
I guess even though a turbine spins a whole lot faster than a piston engine ever thought of, there is less shear stress, right? So a lower group basestock would be more than adequate to reduce the varnish build up.
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