There’s a gap for dirty oil to bypass the media. About 15% was calculated by @ZeeOSix when I measured the opening.
ACDelco PF63 C&P
- Thread starter BrendanC
- Start date
Gotcha.
I wasn't thinking about the lower end. I was thinking about the upper end being held. Makes sense now.
There is still flex in the leaf spring, and therefore do keep force down into the end cap and the guts tight. When it's all ruffled and warped (as show in post 19) then there can be a big gap where dirty oil can leak past the media. It's simply a metal-on-metal "seal", so it needs to be flat and smooth to seal in any decent way.
Yes, WCW also had 'one' ACD that passed flashlight testing. However, a couple of his subsequent ACD dissections failed the tests. The one minor positive imo, at least unlike the Fram FE you're not paying ~$13 for a compromised seal area.
Last edited:
I don't really buy that. If you're saying that it's acting as a spring, maybe. Otherwise, the fenders on my old 4Runner are springs, and so is a can of Coke. Both will return to their original shape after being distorted by light pressure. Heavier pressure will permanently distort them, just as any sort of serious pressure will bend that spacer in the filter can (when it's removed).
Also, the fact that engineers and copy writers call it a leaf spring doesn't really make it one. I think it was Abraham Lincoln that asked if a dog has four legs, but we call the tail a leg, how many legs does it have? Four, because calling the tail a leg doesn't make it one.
I realize that the stamped spacer may flex slightly when the filter is assembled, but its curved edges pressing against the outside of the can keep it from moving very much. Not sure how much compression is used, but it seems to be enough generally to make an impression on compressible filter element ends.
Anything that can flex without deformation to produce force to be used for some purpose can fall into the basic category of a "spring". Just because it could be distorted with too much force doesn't mean it's not acting like a spring as the design intended.
What would you call it? It's more than just a "spacer" ... it also flexes under force. It has to flex some to put a decent amount of force on the media cartridge to keep everything tight. Should it be called "The flexible spacer that puts pressure on the filter guts"? Oh wait, maybe it should just be called the "leaf spring" like it's been defined for decades in the oil filter world.
It's the name the oil filter industry and people who understand oil filter construction have been calling it for decades.
Yes, that's another function of the leaf spring if designed right ... to essentially keep the media cartridge centered in the can on the dome end.
In the end it doesn’t matter what we think. The industry calls it a spring or leaf spring. So that’s the correct verbiage to use when discussing filters. Unlike a favorite YouTube personality that called a bypass valve a one way check valve….or an ADBV plastic.
Last edited:
Sigh… OK, I guess if car fenders and cans of sody-pop are springs, I got nothing. I may not wish to call a stamped piece of sheet metal a spring, but I’ll try not to argue.
