Originally Posted By: ZeeOSix
Originally Posted By: KCJeep
Originally Posted By: crazyoildude
louvers... Not my favorite although it seems to help the media from not tearing by (in my opinion) slowing down the oil flow.. Im sure that comment will bring some other beliefs..
Slowing down the oil flow through the louvers would INCREASE stress on the media, not decrease it. Although the whole thing is a moot point anyway.
A reduction of flow rate through a fixed opening means the flow rate through that opening has been decreased and 'slowed down'.
What a whole bunch of louvers does is help more evenly distribute the oil flow through the media. That in turn helps reduce concentrated areas of higher flow rate, which helps reduce the stress on the media in those locations.
If there were only two large holes in the center tube, then those two large holes would have to flow all the oil volume and it would also increase the stress on the media at those points because the flow volume per hole would be large. Evenly distributing all the flow through hundreds of smaller holes or louvers eliminates localized stress on the media due to concentrated high flow areas.
Louvers are fine if they are open and clean edged. They are becoming the prevalent type. The placement and number of holes though, within reason, doesn't change the stress on the media much if any, IMO. The oil flows through the media, through the valleys between pleats, and out the holes mainly. Some flows through the points of the pleats based on area. Witness Fram Ultra skimpy hole spacing. Plenty of solid tube on Frams. The Toyota longer filter OI installed recently has about the bottom 1/4 of the center tube with no holes. Oil flows up the valleys to the holes and out. As long as the area of the holes is greater than the inlet holes and there are holes near valleys it shouldn't matter.