While we're on the subject of cheap filters......

[The_Champ]

Originally Posted By: BigAl
Gary, a free flowing filter can't can't give your oil pump more displacement, but no pump puts out the same flow regardless of back pressure. There is always a certain amount of "slip" (oil that moves backward through the clearances in the pump)and slip increases with pressure. A more restrictive filter might go into bypass more often as well.

However . . .

I seriously doubt that the center tube in ANY automotive filter has enough restriction to cause a meaningful or even measurable decrease in flow. Media, possibly, but center tube? Very doubtful.

The plastic center tube of an Ecore filter is plenty strong. Since it's so open, I do wonder if it supports the media as well as a metal core . . . but I haven't heard of any big problems in the field.


In tests done by Champion Labs, our nylon core of our filter actually has a higher collapse strength than our metal center tubes in our automotive filters.

 

[Gary Allan]

Quote:
Gary, a free flowing filter can't can't give your oil pump more displacement, but no pump puts out the same flow regardless of back pressure. There is always a certain amount of "slip" (oil that moves backward through the clearances in the pump)and slip increases with pressure. A more restrictive filter might go into bypass more often as well.


Sure, you will have marginal losses ..but AFAIK, no swinging member here has any data on it ..nor any idea the variance. I'd say that in my observations, the differences are so little that you can't see a difference day to day that amounts to 1 PSI difference. That is, I'd say that you're dwelling in the "inches of water column" factional realm.


Everyone here can cling to the notion that a filter is tighter or looser. While this is true, it's about as important in 99.44% of the time as whether you tipped the oil bottle upside down for 10 minutes or 2 hours.

I don't care how many lanes of traffic you have on a highway, it can be 40 lanes wide or 4 lanes wide. It make little difference in bumper to bumper traffic with single lane exit ramps. Below the pump relief level ..the filter just isn't even there.

Now let's say you have a lame pump, one that is worn, then sure, you can get HLA noise when switching from one filter to another. Don't blame the filter ..which works seamlessly on millions of units for being "too restrictive". The oil pump is junk.

The same notion may work for someone like Patman. He shifts at the redline and will have the oil flow jerking around with momentum that may not be able to match the pump output. He may see a slight difference between one over another.

This is all handled, in "fit" engines, with the pump relief valve and the filter bypass valve. It contains it, typically, to a very narrow range.