Searched and did not find an answer to my question. As the title suggests, I installed an Amsoil BMK21 bypass with the BP90 filter on my 2007 Honda Civic Si at 93k miles. The car is driven hard/raced, and I have many years of used oil analysis taken pre-bypass showing great results (thread: https://bobistheoilguy.com/forums/ubbthreads.php/topics/3875263/'07_Civic_Si_Amsoil_ss_0w30_8k#Post3875263). The next UOA will be the first one post-bypass install. The bypass was installed during an oil change with 6 fresh quarts of Amsoil AZO 0w30 on 9/11/15. I currently only have 7000 miles on this oil fill with one full quart of makeup oil added. I plan to get it analyzed soon. My question is in regard to the way the bypass setup could skew UOA results. Since none of my previous used oil analysis included using a bypass setup, future results seem less comparable to old results. The way I think of it, the bypass filter is 98.7% efficient at two microns. The full flow Amsoil Ea15k13 filter is 98.7% efficient at 20 microns. Won't filtering particles with the same percent efficiency at 18 less microns also filter wear metals in the 3-19 micron range that oil analysis would usually register (assuming Blackstone Lab's equipment registers particles of this size)? Is this thought process on the right track? Could I use an extraction pump to analyze this oil (without changing it) to keep an eye on it? Should I sample as usual when I change the oil? Or do I need to cut the bypass filter open and send a sample of the pre-bypass filter media oil to Blackstone?
Bypass Filter and future UOA
- Thread starter Guitarman200806
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Wear particles are in the submicron range so bypass filtration shouldn't have a large affect on wear. Bypass filtration is primarily for extending lubricant life. I wouldn't do anything extra crazy just keep sending used oil analysis and don't even worry about the bypass.
dnewton3
Staff member
BP filters most certainly will affect a used oil analysis. Typical ICP spectro machines will only see particle up to about 5um in size. But your BP filter is reasonably efficient at 2ish um.
The thing that none of us can tell you is HOW MUCH the BP element will skew data. Some theorize it won't do much; others take a different view. But at this point, I know of no study or article that directly proves just how much this effect matters. I am 100% confident that it will affect the counts, but I have zero ability to tell you by how much. And neither does anyone else.
The thing that none of us can tell you is HOW MUCH the BP element will skew data. Some theorize it won't do much; others take a different view. But at this point, I know of no study or article that directly proves just how much this effect matters. I am 100% confident that it will affect the counts, but I have zero ability to tell you by how much. And neither does anyone else.
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So is it worth sampling normally the next time I change the oil? I just feel like the bypass element filters out wear metals and would "hide" wear that UOA would previously show. If I can't compare it to my previous tests, I'm basically paying to see if the oil itself held up and I wouldn't have any accurate summary of wear?
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Originally Posted By: Guitarman200806
So is it worth sampling normally the next time I change the oil? I just feel like the bypass element filters out wear metals and would "hide" wear that UOA would previously show. If I can't compare it to my previous tests, I'm basically paying to see if the oil itself held up and I wouldn't have any accurate summary of wear?
You have to get a before and after particle count to see ant differences.The main advantage of a bypass filter is to prolong the oil change intervals. Bypass filters do lower the the amount of crud in the oil .
So is it worth sampling normally the next time I change the oil? I just feel like the bypass element filters out wear metals and would "hide" wear that UOA would previously show. If I can't compare it to my previous tests, I'm basically paying to see if the oil itself held up and I wouldn't have any accurate summary of wear?
You have to get a before and after particle count to see ant differences.The main advantage of a bypass filter is to prolong the oil change intervals. Bypass filters do lower the the amount of crud in the oil .
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