Virgin FE7317 cut open w/light to bypass seal area.

[4WD]

This one shows two coils doing different jobs:

 

[ZeeOSix]

More chits and giggles pics!
This from video on Super Tech filter. Very dramatic demonstration of BIG TIME failure of flashlight test. Note the very significant “nubs” on the sides of the bypass. They appear to be there to “secure” the valve body in place, However, they result in significant “voids” along the sides, allowing light to pass easily. I think this is instructive in understanding what’s allowing light to pass in other designs similar to this, but not as dramatic. Look closely at the bottom pic and you can spot the nubs protruding.
Again, this begs the question >>>How, if at all, does this impact bottom line filtration efficiency?<<<<<

View attachment 238518

View attachment 238519

"Nubs" are fine as long as the actual metal-to-metal sealing interface is done right. Like in this thread (link below), there are "nubs" on the inside of the center tube near the face of the end cap to hold the leaf spring tight, but the leaf spring seals well because it's flat and smooth where it makes the seal with the circular ridge on top of the end cap.

https://bobistheoilguy.com/forums/t...th-bypass-flashlight-test.386754/post-6999418

 

[Sayjac]

Where do you see adhesive? It may be oil if I understand correctly.

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That's it. Easily seen how much better, smother the seal area ring finish is as compared to the topic Champ Labs made FE. No light seen Fram made Titanium, light seen with the topic.

 

[Glenda W.]

I just purchased the next test subject!! My plan.

1. Flashlight test with holes cut in canister.
2. Flashlight test removed from canister to compare.
3. If gaps are found carefully apply some drops of oil on gaps to see if they leak with gravity.

Should be fun!! I will start a new thread to avoid more congestion here.