Different oil filters - reduced oil flow?

[ChristianReske]

Gentlemen,

out of a accident and curiosity me and a friend compared diffenrent oil filters in the garage.

I was stunned to found out that the OEM one (BLUE) have 6 holes with 7mm diameter, this gives a cross sectional area of 231 square mm.
In contrast, the black filter for this car by a very reputable company has 8 holes with 5mm diameter, this gives a cross sectional area of 157 square mm.

So, at first glance, the black filter reduces the oil flow about roughly 30%.
This can´t be good for the engine. Did i miss something?

 

[MParr]

The filters don’t appear to be for the same application.

 

[ChristianReske]

At first glance yes, you are right.
But the black one is the recomended one for this car. Checked twice at the Hompeage / online catalouge of the manufacturer.
The maker of the car uses big and small oil filters, the aftermakets ones are also big and small ones, depending wich company makes them. You can use whatever you want.

The main difference is that the bigger ones are meant for longer OCIs.

The difference in size of the oil inlet holes is what puzzles me...

 

[viscous]

Check out these threads for concerns about small inlet and outlet holes:
https://www.bobistheoilguy.com/forums/threads/fram-inlet-holes.283872/
https://www.bobistheoilguy.com/forums/threads/fram-xg-10060.274473/

I put the xg 10060 on yesterday but took it off today. I just can't see how 3 rows of holes that are only 1/8 inch or so will flow enough oil. I went back to a wix that has 4 rows of holes and are twice the size.

 

[SubieRubyRoo]

If the black one is the recommended one, that means it has enough flow. End of story. Additional "flow" over what's required will not help anything, because you've already satisfied the requirements. Plus, the filter is the very next thing after a positive displacement oil pump... the volume is going to be controlled by the pump, NOT the filter.

 

[MParr]

Okay, the blue one is the OEM filter. A direct cross to the OEM filter is going to be close to the same size.

 

[Job]

If you can measure the inside diameter of the mounting stud you should find its cross sectional area is less than the filter holes. If not it still makes no difference to flow, it just means the pressure goes up or down depending on the size of the restrictions. The oil goes on to squeeze through main bearings which have one or so thousandths of clearance. Unless the back pressure is more than the oil pump relief valve the flow is the same.

 

[ChristianReske]

Thank you all!
Farnsworth, i think you nailed it. Thanks.

 

[ABN_CBT_ENGR]

Flow is volume over time.

With a PD pump pumping volume- the "velocity" of the fluid increases to compensate for the changes in holes ( many large filter banks do this as well to give more filtration time)

Its like the garden hose filling the bucket versus the spray nozzle from the same spigot. Velocities change but the bucket fills at the same rate.

Flow didn't change. ( all other variables equal and unchanged)

Basic pumping and fluid dynamics 100

 

[blupupher]

why don't you post the vehicle info so we can see what the filters are, as well as post the aftermarket filter name and part number.

 

[ZeeOSix]

This can´t be good for the engine. Did i miss something?

Probably missed two things:
1) What's the area of the main oil gallery mounting spud that the filter screws on to? Is is less than 157 mm^2?
2) The base plate total hole area won't matter because of the positive displacement oil pump (the most misunderstood component in the oiling system) ensures the same flow volume. The pump would just have to work a hair harder with a hair more restriction in the oiling system, and therefore its output pressure would increase by a PSI or two. No big deal.

 

[ChristianReske]

Thank you all!

What i have missed complety is the size of the bore of the mounting spud that the filter screws on to, where the oil flows back into the engine after it passed the filter. Likely not more than 12 or 10mm - 15/32" or 25/64" . Much smaller than the inlet holes of the filter. I will measue it next time when i change the filter.

@ blupupher: The blue one is a Honda 15400-PCX-004, the black one is a Mahle OC617. Honda S2000.