Oil & Fuel Oil Filter Flow - Physical Limitation

[Peter 315]

Just buy a OEM filter and Fuhgeddaboudit.....

 

[WinterDeere]

Just buy a OEM filter and Fuhgeddaboudit.....

Then what will we talk about on a Wednesday afternoon? Of course, we only have until morning to figure it out, by the original assertion.

I suspect the resistance offered by the filter element, pleated paper or what-have-you, is going to be an order of magnitude higher than the drain holes, no matter what their sizing and count.

 

[Coyote_CS2220]

All your area calculations are off. Area of a round hole is Pie*(r squared)

Yup.......however the relative difference is still there.
Total Area of holes: =(PI()*((Hole Diameter/2)^2))*#of Holes

A Kioti filter has 8holes X 7mm =38.5mm2 area (308mm2 Total)
A Wix 51334 has 6holes X 6.5mm =33.2mm2 area (199mm2 Total)
A Fram PH3593A has 12holes X 4mm = 12.5mm2 area (151mm2 Total)

Did I open that can of worms........or do we have any mechanical engineers in the audience?

I know the bypass valve is there and these are full flow oil filters by design, but wouldn't the restricted flow area reduce the filtration?

How can the Fram get away with having 1/2 the total outer hole area for oil flow?

 

[newbury]

Reads like a good discussion for BITOG (Bob is the oil guy).

 

[Coyote_CS2220]

Reads like a good discussion for BITOG (Bob is the oil guy).

Yes.....I thought of that first and did a site search to see if my question was asked before.......alas no luck in my site search of Bob.

If I strike out here, I will post on Bob.

I'm thinking it may have something to do with the dynamics of fluid flow......but my education in that area of engineering is limited.

I am certain there is a good reason for these design differences.

 

[WinterDeere]

How can the Fram get away with having 1/2 the total outer hole area for oil flow?

Fram seems to get so much consistently bad press from every expert on automotive oils and filters, that I'd just chalk this up as yet one more reason to buy Wix over Fram. However, do note each have varying grades, for example in Wix:

1. Protec = economy grade
2. Wix original = good stuff
3. XP = extreme duty

The 51334XP has 8 holes, whereas you're calling out the regular 51334 at 6 holes. The flow rates are 9-11 GPM on both, which indicates those holes are not a primary restrictor.

 

[MoKelly]

I see
It’s Wednesday….

Yikes. You are correct.

I’m a day younger!

 

[Coyote_CS2220]

Yes.....I thought of that first and did a site search to see if my question was asked before.......alas no luck in my site search of Bob.

If I strike out here, I will post on Bob.

I'm thinking it may have something to do with the dynamics of fluid flow......but my education in that area of engineering is limited.

I am certain there is a good reason for these design differences.

Sorry, after doing more searching on Bob using different terminology, I find that this has been a big (and complicated) discussion point for some time - sic "Delta-P".

Ya, can of worms.

It would appear that in the mechanics of the total oil pumping/filtration system no filter will restrict the flow in such a way to limit engine lubrication for a variety of reasons.

Quote:
"As for inlet holes size and number, been discussed here many times. As long as the total area all inlet holes at least equivalent to inner area engine block filter mounting stud, all good. I'll say OFs in use today easily meet or exceed that."
One Bob thread on inlet holes

For the filters I quote the hole size that mounts to the engine block filter mounting stud is a M20 (in filter base) so the inside diameter of the return line is about 14 or 15 mm (I will have to measure ID next time I change the filter). This would make the return line ~154-176mm2 area which is in the ball-park of the Fram inlet diameter of 151mm2.

What goes in has to come out, right.

I think I have answered my question, sorry if I got anyone riled.

 

[DarkBlack]

Quote:
"As for inlet holes size and number, been discussed here many times. As long as the total area all inlet holes at least equivalent to inner area engine block filter mounting stud, all good. I'll say OFs in use today easily meet or exceed that."

It’s all good. Nobody should be “riled”. Good topic for a tractor forum. What else would we talk about?

BITOG has some good information, but it also has a lot of anecdotal information and BS.
Take your quote for example. They assume if area is the same it’s the same for flow, but it’s not. Area for area , multiple small passages are more restrictive than an equivalent area single passageway

 

[Coyote_CS2220]

Take your quote for example. They assume if area is the same it’s the same for flow, but it’s not. Area for area , multiple small passages are more restrictive than an equivalent area single passageway

When I read it I thought the same - intuitively at least , but I do not know enough about the dynamics of oil flow to say so factually.

I can see small holes as an issue with very cold viscous oil, but I ask myself why would Fram make small holes (that are more restrictive?) when it would be just as easy to make bigger holes?? Why would Fram go out of their way to produce an inferior product?? Hoping for failure? Orange oil filters with small inlet holes sell better than the competition??

I would think someone with more knowledge of oil flow dynamics would have pointed this out by now.

Intuitively, my speculation is it is all about marketing - perhaps their market research shows enough/targetted people like the look, colour and small holes?? I don't know and after looking over their tech info on their website they certainly don't say much other than they have 12 inlet holes and M20 return.

Intuitively, I am with you - bigger holes are better - at least as far as oil filters are concerned.