Significance of center tube holes

[circuitsmith]

I wonder what fraction of the total flow resistance is due to the holes in the center tube.

I have a Toyota filter and a P1 in front of me.
On both filters circular holes cover maybe 10% of the center tube's surface area.
Other filters have a lot of perforations instead of round holes.
With oil flow pressing the filter pleats against the center tube it seems a lot of the oil has to trickle sideways through a tight area to reach a hole.

 

[SuperDave456]

It all depends on how many Gallons of oil per minute you want to push through the filter.
The thing that will cause the most restriction is the media, that's by design. All those little holes in the center tube add up in surface area.

Considering that filters start to burst around 250-300 PSI.
I can only imagine the only thing that would cause something like that is some kind of mechanical issue. Like the bypass to the pump being blocked and the driver is redlining it on a cold engine.

Besides by then the filter is already destroyed internally, not due to the little holes, but the media collapsing under the pressure.

 

[webfors]

Better to support the media with a solid centre tube than open that space for little to no benefit in oil flow.

That being said, some filters do indeed look lacking in centre tube holes (i.e: purolators).

 

[Pete C.]

Find out the total open area of the center tube. Find the area of the hole in the filter mount on the engine (the hole in the mounting stud) does this answer your question? If the crease of the pleats only covered the holes you'd still not have to worry. but the holes are offset, thus some holes are covered and others are open. Find something else to worry about.

Originally Posted By: circuitsmith
I wonder what fraction of the total flow resistance is due to the holes in the center tube.

I have a Toyota filter and a P1 in front of me.
On both filters circular holes cover maybe 10% of the center tube's surface area.
Other filters have a lot of perforations instead of round holes.
With oil flow pressing the filter pleats against the center tube it seems a lot of the oil has to trickle sideways through a tight area to reach a hole.

 

[circuitsmith]

Originally Posted By: Pete C.
Find something else to worry about.


I was just thinking out loud.
Perhaps you should find something else to be grouchy about.

 

[ZeeOSix]

Originally Posted By: circuitsmith
I wonder what fraction of the total flow resistance is due to the holes in the center tube.

Basically zero. See this thread, which shows the total delta-P across the oil filter in test (a Purolator PureOne PL14006). If the total pressure drop across the filter is 5 psi at 12 gpm, then probably less than 1 psi is attributed to the inlet holes and center core holes flow restriction.

http://www.bobistheoilguy.com/forums/ubb...451#Post1619451

Originally Posted By: circuitsmith
I have a Toyota filter and a P1 in front of me.
On both filters circular holes cover maybe 10% of the center tube's surface area.


I've done this exercise before - you can do it too to prove it to yourself. Measure open area of one hole in the center tube, then multiply by total number of holes. Total area will be more than total area of the hole in the filter mounting stud on the engine. Same can be said about the total area of the inlet holes on the base plate. The filter designers know not to make the holes a choke point for flow.

 

[ZeeOSix]

Originally Posted By: Pete C.
If the crease of the pleats only covered the holes you'd still not have to worry. but the holes are offset, thus some holes are covered and others are open. Find something else to worry about.


IMO, even if a center tube hole was covered by a media pleat edge, it won't be enough to totally seal off the hole. All the holes in the center tube are going to flow.

 

[cp3]

Very significant! If they're not there it's going to be a problem!

Any benefit to the directional perforations over the holes?

 

[Pete C.]

None worth mentioning. Except the cost savings in being able to use thinner coil stock.

Originally Posted By: cp3
Very significant! If they're not there it's going to be a problem!

Any benefit to the directional perforations over the holes?