Wix vs. PureOne - Flow Restriction

[Gary Allan]

Quote:
If you could get 10 gpm out of an oil pump, then that particular filter example you gave would only have a 4 psid across it ... which is well below any by-pass valve setting that I know of, so it really wouldn't be "slammed up against the relief".


The point is, regardless of what the PSID across the media would be @ 10gpm of flow with the 150SSU fluid ..YOUR ENGINE WOULD MOST LIKELY BE SLAMMED UP AGAINST THE OIL PUMP'S RELIEF VALVE AND YOU WOULD NEVER ACHIEVE IT.

Do you still think that a flow rating at a static psi of applied pressure allows you to integrate data as it would be seen in service? PSID is PSID, right? Posted flow potential numbers work well too, right?

Next?

That was a hydraulic filter rating, btw.

Originally Posted By: Nyquist
Continue. I love fluid dynamics!

Originally Posted By: Gary Allan
Now is the point where I field objections.

 

[SuperBusa]

Originally Posted By: Gary Allan
Quote:
If you could get 10 gpm out of an oil pump, then that particular filter example you gave would only have a 4 psid across it ... which is well below any by-pass valve setting that I know of, so it really wouldn't be "slammed up against the relief".


The point is, regardless of what the PSID across the media would be @ 10gpm of flow with the 150SSU fluid ..YOUR ENGINE WOULD MOST LIKELY BE SLAMMED UP AGAINST THE OIL PUMP'S RELIEF VALVE AND YOU WOULD NEVER ACHIEVE IT.


You never specified if it was the filter's by-pass or the engine's oil pump by-pass ... since we were talking about oil filters I'd assume the former. You need to be careful in you discussions to not lead astray.

Originally Posted By: Gary Allan
Do you still think that a flow rating at a static psi of applied pressure allows you to integrate data as it would be seen in service? PSID is PSID, right? Posted flow potential numbers work well too, right?


With a fluid of given viscosity, there is a specific flow vs. delta P curve for every oil filter made. If an engine's oil system resistance is more than the oil filter's (which is surely is), then it's a mute point as the engine becomes the higher "resistor in the circuit".

But, as you've said earlier, an engine's oil pump is ideally a positive displacement pump. So, if an oil pump can put out say 8 GPM at high engine RPM, then the engine and filter will see 8 GPM flowing through them as long as their by-pass valves stay shut. The oil pressure will naturally increase of course as the engine's RPM increases due to the higher flow rate through a "fixed resistance". This is easily seen on any oil pressure gauge as RPMs increase.

Of course, if the filter's by-pass valve OR the engine's by-pass valve opens, then some of that 8 GPM flow will change it's route, and the oil pressure will remain constant at whatever the valve's relief pressure is if the engine's by-pass is active.

Yes, I fully understand that the engine's oil pump by-pass can activate before the oil filter's by-pass ever does ... the engine by-pass is operating on absolute system pressure while the filter's by-pass is operating only on filter delta P.

I think we are on the same page here, but have different ways of looking at the same physics of the system.

 

[Gary Allan]

Quote:
I think we are on the same page here, but have different ways of looking at the same physics of the system.


After a fashion

 

[SuperBusa]

Well, after having some email discussions with the engineers at Purolator, I've decided to go with the PureOne. It has a substantially better beta rating than the Wix/NAPA in the 20+ micron range ... guess that's where they get thier claim of 99.9% filtration rating (Beta 1000) for 20+ microns to be specific. Beta was 2 (50%) for 5+ microns. 5 microns is getting down there. The Wix/NAPA would be my 2nd choice though.

 

[postjeeprcr]

Originally Posted By: SuperBusa
Well, after having some email discussions with the engineers at Purolator, I've decided to go with the PureOne. It has a substantially better beta rating than the Wix/NAPA in the 20+ micron range ... guess that's where they get thier claim of 99.9% filtration rating (Beta 1000) for 20+ microns to be specific. Beta was 2 (50%) for 5+ microns. 5 microns is getting down there. The Wix/NAPA would be my 2nd choice though.


Did they send this information to you in an email or did you talk on the phone? If in an email can you post it here. I am sure many people would be interested in seeing it.

 

[Gary Allan]

I don't think that they claim 99.9%. The boxes I've seen are 98.6 ..which is a much more realistic Beta75.

I don't think there's too many Wix ultra fine hydraulic filters that meet a 2/1000 (usually it's 2/20/75 or 2/75/1000 etc.) 5/20.

 

[SuperBusa]

Originally Posted By: postjeeprcr
Originally Posted By: SuperBusa
Well, after having some email discussions with the engineers at Purolator, I've decided to go with the PureOne. It has a substantially better beta rating than the Wix/NAPA in the 20+ micron range ... guess that's where they get their claim of 99.9% filtration rating (Beta 1000) for 20+ microns to be specific. Beta was 2 (50%) for 5+ microns. 5 microns is getting down there. The Wix/NAPA would be my 2nd choice though.


Did they send this information to you in an email or did you talk on the phone? If in an email can you post it here. I am sure many people would be interested in seeing it.


Yes, it was via email. What I posted above is what the engineer at Purolator told me. I also asked about the flow vs delta P on the PureOne, but he hasn't answered yet ... probably tomorrow, since I sent the email late in the day. Will post info if he responds.

 

[SuperBusa]

Originally Posted By: Gary Allan
I don't think that they claim 99.9%. The boxes I've seen are 98.6 ..which is a much more realistic Beta75.

I don't think there's too many Wix ultra fine hydraulic filters that meet a 2/1000 (usually it's 2/20/75 or 2/75/1000 etc.) 5/20.



Read for yourself.
http://www.purolatorautofilters.net/en-us/products/oil_filters/Pages/pureoneoilfilters.aspx

Purolator engineer told me via email the beta on the PureOne was (his exact email text follows):
"PureOne is 50 % efficient for 5 micron and 99.9 % for 20 micron ratings ... implying Beta = 2 for 5 micron and Beta = 1000 for 20 microns."

Here's the equivalent filter for my car in Wix (NAPA Gold the same). Note beta is 2/20 = 6/19, meaning 50% efficient for 6u and 95% efficient for 19u. Still a very decent filter, but 5% getting through is something I'd rather prevent if possible.

http://www.wixfilters.com/filterlookup/PartDetail.asp?Part=51356

 

[Gary Allan]

Very respectable numbers. The holding capacity is decent too.

 

[Gary Allan]

Quote:
Of course, if the filter's by-pass valve OR the engine's by-pass valve opens, then some of that 8 GPM flow will change it's route, and the oil pressure will remain constant at whatever the valve's relief pressure is if the engine's by-pass is active.

Yes, I fully understand that the engine's oil pump by-pass can activate before the oil filter's by-pass ever does ... the engine by-pass is operating on absolute system pressure while the filter's by-pass is operating only on filter delta P.



I wanted to noodle this a bit more.

The filter media ends up being a bunch of orifices. In most flow conditions, the turbulent nature of flow through them is not apparent as pressure elevations/alterations. When you see the spec'd limits/ratings at a given viscosity, generating a given PSID, you're more or less seeing those reactive inhibitors to flow come to bear.

Whenever an oil pump's relief valve opens, there is elevated PSID across the filter. It's the difference between the max pressure (not always max) ..and the pressure developed by less oil flowing to the engine ..developing less back pressure.

Aside from loading factors that are lowering the flow rate (at visc) at which squeezing the oil through the smaller orifices (or fewer of them) ..the only time you can have any appreciable filter bypass activity ..or rather ...more than negligible PSID across the filter ..is when the pump is in relief.

The two, for the most part, are 100% inter-related (aside from loading qualification mentioned).