micron rating question

[oil pan 4]

I do have engines with differential pressure on the engine oil filters but I'm going to see how long can run them before they clog, don't really care about the difference between various filters.
What is the difference between a hydraulic filter running cold fluid and an engine oil filter running cold oil on start up?

Obviously all filters are not created equal. But it looks like the wix rock catcher still flows more than the fram ultra.
The royal purple shows how much difference there can be and the fram shows how little difference there can be between a rock catcher and good filters.
And I was talking about cold oil and paper filters originally...
Clearly there's synthetic media filters that flow more and catch way smaller than paper filters, I never said there wasn't.

Example I have is with hydraulic filters, wix 57123 vs the wix a31a06ga. The 57123 does 8 microns at 12 to 14gpm the wix a31a06ga does 6 micron at 22gpm because of it's unobtaium glass filter media. Both filters are close to the same size.

 

[ZeeOSix]

I do have engines with differential pressure on the engine oil filters but I'm going to see how long can run them before they clog, don't really care about the difference between various filters.
What is the difference between a hydraulic filter running cold fluid and an engine oil filter running cold oil on start up?

If you don't care about the dP level between engine oil filters, then why suggest running a lower efficiency filter in the winter? - Ref post #12.

Yes, all liquid filters will have higher dP as the fluid viscosity increases, and/or the flow rate increases. Most hydraulic filters are higher efficiency than engine oil filters, and typically also have much more media area to help achieve good dP vs flow performance. There are many factors involved with how the dP vs flow curve looks for any given oil filter, and that along with the bypass valve setting all have to be looked at to conclude if one filter is better suited for an application over the other. Only an ISO 4548-12 type dP vs flow test will show exactly how an oil filter "flows". Just looking at the efficiency is not a good way to determine a filters flow performance. And even if Filter A has more dP vs flow, if the bypass setting is set accordingly then it's basically a non-issue if it has 2-3 PSI more dP at the max engine pump flow rate. PD oil pumps are used for a reason on engine oiling systems.

Obviously all filters are not created equal. But it looks like the wix rock catcher still flows more than the fram ultra.

With a positive displacement oil pump, "more flow" is basically a misnomer. See above comments.

The royal purple shows how much difference there can be and the fram shows how little difference there can be between a rock catcher and good filters.
And I was talking about cold oil and paper filters originally...
Clearly there's synthetic media filters that flow more and catch way smaller than paper filters, I never said there wasn't.

This is again the reason you can't just make a blanket statement that more efficient oil filters don't flow as well (meaning more dP vs flow) as less efficient oil filters. If a slightly more flow restrictive filter (meaning more dP vs flow) doesn't put the oil pump in pressure releif and/or the filter doesn't bypass much if any, then a 2-3 PSI more dP at full oil pump flow rate doesn't really matter.

Example I have is with hydraulic filters, wix 57123 vs the wix a31a06ga. The 57123 does 8 microns at 12 to 14gpm the wix a31a06ga does 6 micron at 22gpm because of it's unobtaium glass filter media. Both filters are close to the same size.

Yes, full synthetic media can flow much better (meaning less dP vs flow) than non-synthetic media - and at the same time be higher efficiency. But it also depends on the total surface area of the media. That's why the total media area went up on the non-wire backed (synthetic blend media) Ultra of same model number compared to the wire backed full synthetic media Ultra.

On a side note - when WIX (or any other filter maker) shows a specification of a "max oil flow rate", there is absolutely no information on what the really means. When WIX says a filter is rated at 6 microns and flows 22 GPM, there is missing information about that statement. What's the efficiency at 6 microns, and what's the oil viscosity and dP associated with the "22 GPM" spec? Is the "max oil flow" spec when the bypass valve starts to open when the oil is at X cSt? If the max oil flow spec is based on the bypass valve setting, then if Filter A has a higher bypass setting than Filter B, then it could have a higher "max oil flow" spec. WIX's max flow spec is nebulous without more information about the basis of the spec.

 

[oil pan 4]

I was talking about bypassing cold old not which one flows more in general. I work on hydraulic system alot, obviously a positive displacement pump doesn't really care about filter flow rates it's just going to send it.
The way I figure it is if the filter "flows more oil" the less likely it is to bypass oil through the bypass in the bottom of the filter next to where the dirt collects...
The positive displacement oil pump doesn't care if there is a big filter, a small filter, no filter, clogged filter, if it's going to push oil through the bypass or not.

When wix says their fiter flows 22gpm,thats their words not mine and it's all I can find on flow unless there happens to be some independent testing.
If they say one of their filters flows more than the other, probably believing them is a good place to start, unless they clearly made a mistake.
Their flow ratings don't always make sense, for example they have a paper 21 micron lawn mower size oil filter about 3 inches in diameter and less than 3 inches long that's rated to flow 9 to 11gpm then they have the same diameter filter that's over double the length, also paper, also rated 21, micron follow rated for 8 to 10gpm. I'm not exactly sure how they come up with their numbers either.
Only difference I see is the small one appears to intended for lawnmowers and motorcycles the the long one appears to intended for John Deere, so probably diesel engines.

 

[ZeeOSix]

I was talking about bypassing cold old not which one flows more in general. I work on hydraulic system alot, obviously a positive displacement pump doesn't really care about filter flow rates it's just going to send it.

Yes, I know ... and I'm talking about how a filter's flow performance can not be determined solely on it's efficiency rating. Gave reasons why ... it's the dP vs flow curve of a filter, and the bypass valve setting which will determine if it will bypass or not in actual use. Also, part of that equation is how thick is the oil, and how much oil volume does the PD put out per RPM. Lots of factors involved, not just the filter's efficiency. That's why it makes no sense to say "use a less efficient oil filter in the winter time", which is what kicked off this whole discussion.

The way I figure it is if the filter "flows more oil" the less likely it is to bypass oil through the bypass in the bottom of the filter next to where the dirt collects...
The positive displacement oil pump doesn't care if there is a big filter, a small filter, no filter, clogged filter, if it's going to push oil through the bypass or not.

Yes, if a filter has less dP vs flow, then it may or may not bypass more ... because it also depends on the bypass valve setting and the engine it's mounted on, meaning what's the oil viscosity and pump volume output vs PRM, and also what's the pump's pressure relief setting? Lots of factors involved. Pretty much any filter could be put into bypass if someone revved an engine real high right after a cold start when the oil is at -25F for example. That's when the vehicle operator must realize to keep the engine RPM down until the oil warms up.

When wix says their fiter flows 22gpm,thats their words not mine and it's all I can find on flow unless there happens to be some independent testing.
If they say one of their filters flows more than the other, probably believing them is a good place to start, unless they clearly made a mistake.
Their flow ratings don't always make sense, for example they have a paper 21 micron lawn mower size oil filter about 3 inches in diameter and less than 3 inches long that's rated to flow 9 to 11gpm then they have the same diameter filter that's over double the length, also paper, also rated 21, micron follow rated for 8 to 10gpm. I'm not exactly sure how they come up with their numbers either.
Only difference I see is the small one appears to intended for lawnmowers and motorcycles the the long one appears to intended for John Deere, so probably diesel engines.

I know it's Wix's words/specs. I've called Wix Tech line to ask what that "max flow" spec actually means because it's totally nebulous (as your examples show), and the Wix Tech line people can never say exactly what it means. Like said earlier, if the bypass valve of a specific filter is part of the "max flow" equation, then it makes it even more nebulous of a specification. It's a useless spec when you don't know what it's actually based on.

 

[oil pan 4]

I have some limited data on cold filtering.
On my small engines that ran a bypass filter I use a Baldwin bt344-s hydraulic filter that rated is 10 micron normal 27 micron absolute, so a unremarkable paper filter. Physical size is 3.7 inches wide and less than 4.5 inches tall, approximately the size of what you find on a typical v8 pickup truck engine and is rated between 9 to 12gpm depending on who makes it, Baldwin doesn't seem to have flow ratings posted.
Running the bypass wide open on a small engine, getting around 1gpm cold and by cold I mean like 90F. That's producing about 10psid across the filter. This is with 10w-40 oil.
Normally I manually set a valve to bleed off a little case pressure so that it's only filtering 1 gallon every 3 or 4 minutes and I get no pressure differential reading at that rate. The filter is pretty new only has about 8 hours on it.
Yeah around 1gpm flow on a summer day, 10w-40 oil making 10psid isn't encouraging as the typical bypass on an engine oil filter is 8 to 11psi and a typical engine with a full flow oil filter setup is probably flowing more than 1gpm even at idle.

 

[ZeeOSix]

Yeah around 1gpm flow on a summer day, 10w-40 oil making 10psid isn't encouraging as the typical bypass on an engine oil filter is 8 to 11psi

What's the bypass setting on that Baldwin filter? Most oil filters for auto engines these days are quite a bit more than 8 to 11 PSI.

 

[ZeeOSix]

I have some limited data on cold filtering.
On my small engines that ran a bypass filter I use a Baldwin bt344-s hydraulic filter that rated is 10 micron normal 27 micron absolute, so a unremarkable paper filter.

If you're going to use a bypass filter setup, why not use a filter that's meant for a bypass filter setup, and higher efficiency than 99% @ 27μ.

 

[oil pan 4]

If you're going to use a bypass filter setup, why not use a filter that's meant for a bypass filter setup, and higher efficiency than 99% @ 27μ.

Don't worry about my application. I added this filter to a small engine that otherwise has no oil filter using junk that I had laying around. This is not a traditional bypass filter setup. It is a bypass as in it bleeds off some of the line pressure, bypasses it through a filler on its way back to the oil sump, bypassing the normal oil flow route. Idk what else to call it.
If I look on the WIX website filter finder about 80% to 90% of their oil filters with 3/4-16, 13/16-16 and 20x1.5 threads you know typical car, SUV and pickup oil filters and are made with a bypass. Those bypass filters are rated usually 8 to 11psi so I would say 8 to 11psid is very relevant. A few are 14 or 15 psi, some are 20 to 22 those are usually listed as hydraulic filters and a very few are in the 30psi or higher range.
One reason I used a hydraulic filter was because it had a built in 20 to 22psi bypass I'll change the filter when when the psid gauge is in or near the red when the engine is warm and filtering 1 gallon every 3 to 4 minutes.
Yeah it is kind of unsettling that around 1gpm of flow through a rock catcher on summers day with 10w-40 oil could be unseating the bypass valve...
I'll collect more data when I can, such as use a beaker and stop watch to get actual flow numbers and at colder temperatures this winter.

 

[ZeeOSix]

One reason I used a hydraulic filter was because it had a built in 20 to 22psi bypass I'll change the filter when when the psid gauge is in or near the red when the engine is warm and filtering 1 gallon every 3 to 4 minutes.

There's most likely a reason that filter has a high bypass valve setting - it probably has a relatively high dP vs flow curve. What's the dP when the oil is at 200+ F ?

So you're trying to conclude that automotive oil filter's have the same dP vs flow performance as hydraulic application filters? Not so sure I'd trust that conclusion without seeing valid test data.

Maybe put something like an Ultra or Titanium or similar on there and see if the dP is different under the same flow conditions.

I'll collect more data when I can, such as use a beaker and stop watch to get actual flow numbers and at colder temperatures this winter.

So all these oil flow numbers you're claiming are just a guess at this point? If you haven't made that measurement, then you don't know what it is without guessing.

 

[oil pan 4]

How much difference do you think there is going to be between a paper element hydraulic filter and a paper element oil filter rated for similar microns?
I bet its not going to be that much difference.
At 150f running max bypass flow I get no reading on the psid gauge so it's likely fine as the engine gets close to being warm, at least on a newish filter.

I used to test turbo charger oil flow I got a real good idea what 1qt to 1gpm looks like.

When I made these observations I wasn't even trying to test filter flow I was just seeing if my cheap psid gauges showed a reading. What I saw was not encouraging, I really didn't expect to see a reading with 10w-40 oil at 90f running less than 2gpm on a new filter.
If you don't believe it feel free to test it your self I'm good with being wrong on this.

I'm working on getting a decent psid gauge that doesn't not have a retarded low range. What I have now are just hydraulic filter change gauges, they don't really register anything less than 4 to 5psi. I'm looking at getting one with a nice expanded 0 to 20psi scale.

Based on what I have seen I'm already looking at over sized filters with higher pressure bypasses for the vehicles.
Found a double length oil filter for my wife's car with a 15psi bypass. The Hyundai filters do have a bypass, Don't know what it bypasses at, but it's wix replacement has a 8 to 11psi bypass.

 

[oil pan 4]

Well that was fast. I made a low ball offer on this for $20 shipped and got it.
It appears to be adjustable if not just subtract 3psi off the reading.

 

[ZeeOSix]

How much difference do you think there is going to be between a paper element hydraulic filter and a paper element oil filter rated for similar microns?
I bet its not going to be that much difference.
At 150f running max bypass flow I get no reading on the psid gauge so it's likely fine as the engine gets close to being warm, at least on a newish filter.

Yeah, seems your gauge(s) aren't the best. Here are some other members who did some on the vehicle dP testing, which shows way less than 10 PSI dP at 70-80F "cold start" on automotive oil filters at elevated RPM which would probably be way more than 1 GPM of oil flow. Lots of stuff to read, but it interested here are the links. There use to be graphs in Jim Allan's threads, but with the board migration to new software seems they were lost.

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[oil pan 4]

That's why I would specifically use a mechanical psid gauge hooked up to the filter head.

Well on an old V8 small block Chevy, one of the few engines where people bothered to figure the flow rate of the pump and how much oil actually goes through the engine. With hot 10w-30 the engine at idle will have no problem pushing 2.5gpm throughout the engine with 20 to 30psi. A
So around 1gpm cold seems well within the realm of possibilities.

Almost 3psi retriction on a new filter is encouraging. With hot oil and a new filter I'm also seeing near zero psid on the filter, a least less than 4 to 5 psi. Could be 3psi.

14c is pretty nice out, new filters are always good. I'm thinking more like properly cold and not so new filters.

 

[oil pan 4]

Also I did take apart an engine for rebuild that had built in 3 to 5psi bypass valve about 20 years ago.

 

[ZeeOSix]

Also I did take apart an engine for rebuild that had built in 3 to 5psi bypass valve about 20 years ago.

What engine? That's a very low oil filter bypass setting. How did you determine it opened at 3 to 5 PSI?

 

[oil pan 4]

Easy, measure surface area of the oil filter bypasses plug, was about 1/3 of a square inch surface area and it took a about 1lb but less than 2lb pressure to offset the spring. The spring just seemed really weak, that's why I bothered to look closer at it. It was an old 6.2l diesel engine, I dramatically increased the amount of seat force in the bypass spring by using the both the old and new springs and stretching them.

 

[ZeeOSix]

Yeah, a 3 to 5 PSI filter bypass valve is not ideal in an engine like that unless the oil filter was the size of a 55 gallon drum, lol.

 

[oil pan 4]

Yeah, a 3 to 5 PSI filter bypass valve is not ideal in an engine like that unless the oil filter was the size of a 55 gallon drum, lol.

I'm thinking oversize filters in everything that will fit them.