I am looking at two Wix part numbers. 51356 and 51357. I emailed wix to see what the difference was, and they responded "51357 has a clean side anti-drain back valve, 51356 does not."
I believe what it means is that the 51357 has the adbv at the BASE of the filter, Whereas the 51356 has it at the DOME end (or top) of the filter. FWIW Oldtommy
It's the first Asian filter with such a configuration I've heard of. There are some for higher end Euro's that are like this. It basically tries to prevent the filter from draining in either direction.
So, good? bad? what is interesting, is I have the "Kia" oe version of the filter, and if you look inside, the bypass valve is almost at the top end of the filter (threaded end) and there is no tube with holes visible when you look in. I'm guessing all the oil runs through this "valve" ? I'll try to post a picture, not sure how it will turn out.
One of the PureOnes has that feature I forget the number but have one here somewhere, and also the Mahle OC-47.
It is supposed to prevent a thread side down filter from ever emptying.
Of course, if you like to pre-fill the filter when changing oil as I do, that presents a problem.
The Mahles I used all drained oil after use anyway when I turned them upside down, so I don't know how long the thing works.
I think I remember seeing a pure one that was similar (for a Z-Tec engine) however, I thought I could still see the filter element and holes in it? May be not, only used one once a long time ago.
Anyway, to get to my main purpose of this post, Does the Kia filter or the 51357 look like a better filter for vehicles that use the 51356 (like my mitsu v6) I just wonder about oil flow or restriction?
Can't see the center tube with these deals in there.
I don't see how restriction could be a problem IF the filter is specified for the car.
The outlet ADBV spring is very light on the PureONE and Mahles I cut open.
The only problem I can foresee is maybe if the filter is not specified for the car, and has one of these devices, there is the possibilty that the oulet ADBV could be blocked from opening all the way by the filter mount nipple because the valve plate opens toward the nipple.
If the nipple screws into the filter too far, the little valve plate could be stopped by it.