Would you use free Purolator classics???

[ZeeOSix]

Originally Posted By: SilverC6

The discussion for oil passing through the filter media vs. the bypass in this instance is the same discussion for why adequate filtration is still occurring in a torn Purolator Classic/Pure One. The headloss through the media is less than the loss the fluid sees in routing to the tear location and pushing through the orifice (tear).


The flow will always increase through the path of least resistance. Big hole(s) in the media is the path of least resistance, so there will be always increased flow through that hole vs no hole at all. Enough hole area, and it would essentially be like the oil filter was in bypass 100% of the time.

Is that bad? ... maybe not, but I certainly wouldn't want to use an oil filter if the bypass valve was stuck open 100% of the time.

This was out of book entitled "Engineering Fundamentals of the Internal Combustion Engine".

"As a filter is used, it slowly becomes saturated with trapped impurities. As
these impurities fill the filter pores, a greater pressure differential is needed to keep
the same flow rate. When this needed pressure differential gets too high, the oil
pump limit is reached and oil flow through the engine is slowed. The filter cartridge
should be replaced before this happens. Sometimes, when the pressure differential
across a filter gets high enough, the cartridge structure will collapse and a hole will
develop through the cartridge wall. Most of the oil pumped through the filter will
then follow the path of least resistance and flow through the hole. This short circuit
will reduce the pressure drop across the filter, but the oil does not get filtered."

 

[CarbonSteel]

Originally Posted By: SilverC6
Originally Posted By: 2015_PSD
Originally Posted By: SilverC6
And if it's cold like it is here, all filters are in bypass every morning anyway.
This is not necessarily true irrespective of the filter brand. Jim Allen did quite a bit of testing on DP and bypass events and found they are far less frequent than people would like to believe.

See here and here.
Thanks for the reference material. The discussion for oil passing through the filter media vs. the bypass in this instance is the same discussion for why adequate filtration is still occurring in a torn Purolator Classic/Pure One. The headloss through the media is less than the loss the fluid sees in routing to the tear location and pushing through the orifice (tear).
You are welcome. However, I do not see this as an apples to apples comparison because the DP for the media versus the bypass is far different than the DP for the media versus a tear (the tear does not need to be "opened" as the bypass does). Also, while not all of the oil is passing through the tear some of it definitely is and nothing needs to open for it to do so once the media is torn.

 

[oldmaninsc]

"Would you use free Purolator classics?"

No, not on any of my vehicles.

 

[Nick1994]

Not even if someone paid me.

An oil filter has 1 job, and that is to filter. If it fails at it's one job, then what's the point? I just can't even understand why anyone would want to use them.

Would you Purolator users use tires that have been widely known to blow out at even as little as 5,000 miles? Sure maybe no wheels have been harmed in the Purolator Tire blowouts yet, but that tire has failed at it's 1 job.

And we can't know if they cause engine damage, BITOG reported tears are probably only .0001% of the Purolator oil filters used. They're used in quick lubes all over. If someone had some damage, they wouldn't think it could be the re-badged Purolator oil filter on there from Jiffy Lube. They'd be stuck with the bill.

Junk.

 

[goodtimes]

Originally Posted By: ZeeOSix
Originally Posted By: SilverC6

The discussion for oil passing through the filter media vs. the bypass in this instance is the same discussion for why adequate filtration is still occurring in a torn Purolator Classic/Pure One. The headloss through the media is less than the loss the fluid sees in routing to the tear location and pushing through the orifice (tear).


The flow will always increase through the path of least resistance. Big hole(s) in the media is the path of least resistance, so there will be always increased flow through that hole vs no hole at all. Enough hole area, and it would essentially be like the oil filter was in bypass 100% of the time.

Is that bad? ... maybe not, but I certainly wouldn't want to use an oil filter if the bypass valve was stuck open 100% of the time.

This was out of book entitled "Engineering Fundamentals of the Internal Combustion Engine".

"As a filter is used, it slowly becomes saturated with trapped impurities. As
these impurities fill the filter pores, a greater pressure differential is needed to keep
the same flow rate. When this needed pressure differential gets too high, the oil
pump limit is reached and oil flow through the engine is slowed. The filter cartridge
should be replaced before this happens. Sometimes, when the pressure differential
across a filter gets high enough, the cartridge structure will collapse and a hole will
develop through the cartridge wall. Most of the oil pumped through the filter will
then follow the path of least resistance and flow through the hole. This short circuit
will reduce the pressure drop across the filter, but the oil does not get filtered."

Virtually all the oil will flow through a good size tear until the pressure difference is reached and a small amount of oil will start flowing elsewhere. Depends on the tear/hole size. It could be zero oil is filtered in a smaller engine not driven hard with modern thin oil. Not good at all, good reference to explain with some authority. I wouldn't take free Purolators of any kind until the new ones show promise. The Boss is looking good with the Mann European style element. Too bad they didn't acknowledge directly they had an issue. For marketing they were smart though as most customers don't know about the issue, don't care, or are in denial and still buy what they bought before.

 

[53' Stude]

NO, I would NOT use a free Puro or "made by Purolator" filter. Never will either as I sent my MC-910S to my friend to melt down to new steel

 

[MinamiKotaro]

Of course. I'm not afraid of Puros.

 

[SilverC6]

Originally Posted By: goodtimes
Originally Posted By: ZeeOSix
Originally Posted By: SilverC6

The discussion for oil passing through the filter media vs. the bypass in this instance is the same discussion for why adequate filtration is still occurring in a torn Purolator Classic/Pure One. The headloss through the media is less than the loss the fluid sees in routing to the tear location and pushing through the orifice (tear).


The flow will always increase through the path of least resistance. Big hole(s) in the media is the path of least resistance, so there will be always increased flow through that hole vs no hole at all. Enough hole area, and it would essentially be like the oil filter was in bypass 100% of the time.

Is that bad? ... maybe not, but I certainly wouldn't want to use an oil filter if the bypass valve was stuck open 100% of the time.

This was out of book entitled "Engineering Fundamentals of the Internal Combustion Engine".

"As a filter is used, it slowly becomes saturated with trapped impurities. As
these impurities fill the filter pores, a greater pressure differential is needed to keep
the same flow rate. When this needed pressure differential gets too high, the oil
pump limit is reached and oil flow through the engine is slowed. The filter cartridge
should be replaced before this happens. Sometimes, when the pressure differential
across a filter gets high enough, the cartridge structure will collapse and a hole will
develop through the cartridge wall. Most of the oil pumped through the filter will
then follow the path of least resistance and flow through the hole. This short circuit
will reduce the pressure drop across the filter, but the oil does not get filtered."

Virtually all the oil will flow through a good size tear until the pressure difference is reached and a small amount of oil will start flowing elsewhere. Depends on the tear/hole size. It could be zero oil is filtered in a smaller engine not driven hard with modern thin oil. Not good at all, good reference to explain with some authority. I wouldn't take free Purolators of any kind until the new ones show promise. The Boss is looking good with the Mann European style element. Too bad they didn't acknowledge directly they had an issue. For marketing they were smart though as most customers don't know about the issue, don't care, or are in denial and still buy what they bought before.


The tears presented in Purolators here on BITOG do not fall in the large or "good sized" category, however. They are small and insignificant compared to the overall filter surface available for flow.

And Z06, your quote is accurate. When the rest of the filter is clogged and a tear occurs, yes the flow will move to the tear. But the assumption in your example is the remainder of the filter is blocked. That is not the condition in an otherwise healthy Purolator with a small tear. The permeability of the filter media is very high, by design.

You folks need get a better understanding of fluid mechanics.

Or maybe it's just the Kool-aid talking....

 

[ZeeOSix]

Originally Posted By: SilverC6
The tears presented in Purolators here on BITOG do not fall in the large or "good sized" category, however. They are small and insignificant compared to the overall filter surface available for flow.


I'd say having a couple of tears this large is pretty significant.



Originally Posted By: SilverC6
And Z06, your quote is accurate. When the rest of the filter is clogged and a tear occurs, yes the flow will move to the tear. But the assumption in your example is the remainder of the filter is blocked. That is not the condition in an otherwise healthy Purolator with a small tear. The permeability of the filter media is very high, by design.

You folks need get a better understanding of fluid mechanics.

Or maybe it's just the Kool-aid talking....


Even if the filter was brand new with a couple of tears as large as the photo above, there will certainly be some good flow going through those holes. Fluid will still take the path of least resistance - especially when delta-p across the media is higher due to cold oil and high engine RPM. A wide open hole is far more non-restrictive than even clean filter media is.

Only "Kool-Aid talking" is see is saying that torn filter media is OK.

 

[Nate1979]

^^^^Take that hole times 4 and you have the failure that many of us had.....

 

[Garak]

Originally Posted By: ZeeOSix
I'd say having a couple of tears this large is pretty significant.

And, even if that had really no effect on filtration, I don't recall choosing to pay for a filter that tears under normal usage. So, until they don't, I won't.

 

[CarbonSteel]

Originally Posted By: Garak
Originally Posted By: ZeeOSix
I'd say having a couple of tears this large is pretty significant.
And, even if that had really no effect on filtration, I don't recall choosing to pay for a filter that tears under normal usage. So, until they don't, I won't.
This is my stance on the matter as well. Call me a fanboy of another brand but I am not going to pay for something that has definitely shown a propensity to fail. Besides, there are PLENTY of other filters that have not shown this defective nature.