|Topic Review (Newest First)|
|06-22-2021 06:14 AM|
|06-22-2021 02:12 AM|
|Dust Devil||If you can point out where I'm going over your head, I might be able to do that but there is only so much simplicity that you can use to describe a complex system before the description becomes garbage.|
|06-22-2021 12:20 AM|
I fear you risk losing your readers.
Us shade tree mechanics soon lose the will to read stuff wot is hard to read.
|06-21-2021 02:13 PM|
About filter weight, steel is pretty cheap, if a filter company wants a "quality" weight, they can just thicken up the steel somewhere.
Of course a quality filter is not likely to be the lightest filter available, you can't really tell without cutting it apart and the German filter might weigh less if their steel stamping machines are better so they can make a thinner can.
Heavy didn't work out so great there.
|06-21-2021 02:00 PM|
The bypass valve does not set the pressure drop in an oil filter. Ideally your bypass valve will never open in your filter because it is only there to open if the filter clogs enough to create too much pressure in the can or tear the filter media. It only opens so the filter doesn't cause oil starvation.
The actual spec of an oil filter relief valve is chosen based on how clogged a filter can be tolerated and how long it will take to clog that much vs. the manufacturer's prescribed oil (and filter) change interval (maybe lease terms and warranty terms too).
The oil pump bypass is a different story, it opens when the volume of oil pumped is so great the oil pressure increases to a level that is unnecessarily high for proper lubrication and the bypass reduces parasitic drag from the oil pump and stress on the oil pump driveshaft.
As for your understanding of fluid dynamics, here is a small lesson, fluid dynamics mostly falls in to two categories: compressible fluid dynamics and incompressible fluid dynamics. They are two different topics of study because they are quite different. Air is a compressible fluid, oil is an incompressible fluid. I have studied both, formally and informally. I would not call myself an expert but I'm sure you can understand why I trust my gut feeling more than the knowledge of a person who doesn't see the distinction between compressible and incompressible fluid dynamics.
I stand by my previous statement either side of an oil filter will have will have equal pressure across the surface of the element. To be more clear, the oil pump side of the filter will all see equal pressure and the bearing side of the filter will see equal pressure. Those two pressures are not the same, the bearing side pressure is equal to the oil pump side pressure minus the pressure drop across the element. Thats why I mentioned "either side of the filter element", that would be a stupid thing to say if I thought they were the same.
On the pleated air filter side, it is like I said, "all pressure gradients and boundary layers" which means on one side of a filter you could measure several different pressures depending on the location where the measurement is taken due to the irregular shape of the pleats and the curving paths that air takes through a pleated filter. Both sides will show this and of course there is a pressure drop across the filter but you might find a situation where you can measure higher pressure on the outlet side than the inlet side depending on the location of where you measure on each side. A particularly bad air filter might even have areas with reverse flow.
Life does get technical when you poke in to how things work.
Predicting the behavior of a system requires an understanding of how all of its elements work. The deeper the understanding, the better the prediction. Of course if you misunderstand, your prediction can be way off.
I try not to speak authorotarily or make predictions unless I'm confident that I understand an issue.
Some people don't feel that way.
|06-21-2021 07:57 AM|
"Air flow and hydraulic flow are very different things."
Air is a fluid.
Water is a fluid (hydraulic is about water)
Air, water, and oil are fluids.
Cement powder, glass and ice are also fluids.
The word fluid covers a lot of things.
Fluid flow is fluid flow.
Air water and oil have different viscosities.
Viscosity tells us the rate of flow.
I'm with you about the corners cutting the rate of flow.
Although, I prefer to describe them as increasing the resistance to flow.
However, shallow pleats have more corners per length on flow assuming the width of the filter mediums are the same.
More corners per foot with shallower pleats means equals more resistance to flow per foot.
More resistance to flow means less oil through your medium.
Which raises the spectre of the relief valve opening as high revs.
When the bypass valve opens unfiltered oil goes round your bearings.
Even worse if the relief valve doesn't open of course.
Your longer can might make the risk less,
The thing we need to know, is the surface area of the medium in your shallow pleated filter, and the surface area of the medium on an OEM filter.
Along with the size of the holes (pores) in the media.
Don't life get "technical" when you poke into how things work?
|06-21-2021 01:05 AM|
You contact their factory about their product.
"I want some group 65 batteries."
"Fine, how thick you want the plates."
You tell him.
He tells you the price.
You do a deal.
You sell the batteries to a pile 'em high sell 'em cheap set-up.
And continue making your batteries in Germany because the home market only buys Germany made stuff.
Yeah, I simplified, but that's largely how it works.
You can near enough tell battery quality by it's weight.
The same kind of / sort of applies to filters.
How about you weigh your filter before you cut it open, and look up the weight of a genuine Hummel Mann filter?
After that, compare hole (pore) sizes, if you can find them.
Filter makers are a lot more secretive than they used to be.
|06-20-2021 12:01 PM|
I'm going to have to look in to where my filter was made, unfortunately I threw away the box weeks ago.
With that said, if Schott can set up in China and make good glass, I see no reason why Hummel-Mann can't set up in China and make good oil filters. It's not rocket science, I would mostly worry about Chinese silicone in the ADBV, the quality of the filter material and the glue. Hummel-Mann probably set up a mostly robotic factory (if they were smart) so the QC is probably fine as long as the materials last.
Almost every country is putting in some manufacturing in China. The reason is partly low cost manufacturing but mostly to access the market of China. I bet this is what Hummel-Mann did because it sounds like they kept their bread and butter in Europe. I only learned of Hummel-Mann when I had to order an oil filter for a Mercedes years ago, as far as I know they weren't really in the market of replacement filters for American cars in America until recently. My guess is Asian manufacture opened up that market for them too because they could compete on cost and they probably needed volume to fill up their new robot (?) factory with work.
I'm looking forward to cutting it open now.
|06-20-2021 11:37 AM|
Originally Posted by WJ60 View Post
My gut feeling is that shallow pleats are fine in oil filters because an incompressible fluid is going to have equal pressure (neglecting the effect of gravity) on all parts of either side of the filter element. An air filter is all pressure gradients and boundary layers so I'm not surprised that more corners reduces flow.
|06-20-2021 11:30 AM|
Originally Posted by Jeepsmsc2 View Post
|06-20-2021 11:08 AM|
The viscosity of Rotella T5 I use is 10w 30.
A one gallon bottle at Walmart is usually about $17.
|06-20-2021 07:59 AM|
|06-20-2021 07:50 AM|
The Beta Ratio is a good way of deciding a filter's quality.
Trouble is, it's difficult to find.
Beta Ratio: 2/20=6/20
Burst Pressure: 400 psi
Filter O.D. (Inches): 2.685 in. Filter O.D. (mm): 68 mm
Flow Rate: 7 - 9 gpm Gasket I.D. (Inches): 2.173 in.
Gasket I.D. (mm): 55 mm
Gasket O.D. (Inches): 2.475 in. Gasket O.D. (mm): 63 mm
Height (Inches): 2.977 in. Height (mm): 76 mm
Media Type: Cellulose Micron Rating: 21
Style: Spin-on Oil Filter
Thread Size (Inches): 3/4-16 in. UNSPSC: 40161504
The Beta Ratio gives a good idea of how good a filter is.
It ain'r easy to get your head round though.
|06-20-2021 04:45 AM|
Originally Posted by Jeepsmsc2 View Post
|06-20-2021 02:51 AM|
As you say 18+ years old.
It was the best I could find.
Plus much of it is still relevant.
According to "Bob is the oil guy" "OEM MANN filters are still made in Germany for BMW/AUDI, etc. However, all aftermarket variants for Chrysler, Hyundai, etc. are all from China. IT's called BRAND manufacturing."
I think the writer is probably correct.
Especially where the brand is marketed under another name.
Full discussion here, https://bobistheoilguy.com/forums/th...-china.176148/
Probably the key questions are,
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