Originally Posted by ABN_CBT_ENGR
Originally Posted by ZeeOSix
Misformed louvers have been seen in more than one brand of oil filters. The first post where I showed bad vs good formed louvers, those were two filters of the same brand and part number ... just made on different days and/or on different machines. Oil filter manufacturing can be sloppy, as can be seen by the many cut & posts just in this forum alone.
Certainly have no problem accepting that but has the same due diligence been done to determine that a legitimate product was being compared ( and not a counterfeit) as has been gone into on other threads about spark plugs?
Also, is the slit opening still within the OEM range of tolerance and doesn't affect the design performance criteria?
So far nothing has been presented but pictures clearly illustrating a visual difference in 2 products but nothing factual or verified showing its legit, within tolerance, creating adverse effects or anything else.
Without checking all of those items listed ( and maybe a few others too) we are left with unsubstantiated commentary and unfounded conclusions based on what peoples perceptions are based solely on a visual look see without all the facts.
All of the filters I've seen with closed up louvers on the local store shelves were not counterfeit. It sounds like you don't believe that legitimate filters on the shelf can have misformed and closed off louvers, just like some people here don't believe certain filters can suffer from torn media (even after hundreds have been reported/posted in this forum) ... unless they see it with their own eyes.
And what do you think the "OEM range of tolerance" is? OEM specs and tolerances of any kind can never be found from the OEM (not even a simple efficiency spec), and are never divulged by OEMs. If anything, center tube design would fall into the total max delta-p specs. Closed up louvers can certainly cause increased delta-p. But again, malformed louvers is a manufacturing issue, not a design issue. If two filters of the same brand and part number have a huge disparity in the way the louvers are formed, then it's clearly an inconstant manufacturing and QA problem.
Like I always say ... make your own decisions on what to use. If someone wants to use filters with nearly totally closed louvers then knock yourself, lol. It's not rocket science to look down the center tube to see if the louvers are opened up, or closed down - so yeah, "perception based solely on a visual look" is the best bet. That's all I need in order to decide if I want to use a filter with louvers or not.