Bypass pressure differences - when do they matter?

[MarvinTheAndroid]

Hi all, I wanted to ask general question about bypass valves. If the reference OEM filter for a particular engine has a stated bypass of 22 psi, and a 3rd-party manufacturer says that their product, with a stated bypass range of 16-28 psi, is a cross for the OEM filter, how do you square that in your head (one value vs a range)? They're not the same obviously, but in practical real world terms, does the difference matter?

Taking it further, in certain applications, if the aforementioned 3rd-party filter is cross-referenced against another product from the same company, whose bypass psi is stated as 22-28, is that acceptable?

For something so supposedly straightforward, it sure is confusing.

 

[BrendanC]

Hi all, I wanted to ask general question about bypass valves. If the reference OEM filter for a particular engine has a stated bypass of 22 psi, and a 3rd-party manufacturer says that their product, with a stated bypass range of 16-28 psi, is a cross for the OEM filter, how do you square that in your head (one value vs a range)? They're not the same obviously, but in practical real world terms, does the difference matter?

Taking it further, in certain applications, if the aforementioned 3rd-party filter is cross-referenced against another product from the same company, whose bypass psi is stated as 22-28, is that acceptable?

For something so supposedly straightforward, it sure is confusing.

if the 3rd party says it is a fit, i spin it on. in certain cases i will often use something with a higher rating (07-15 GM products where i spin an 10575 product on instead of the smaller filter)

 

[Hirev]

Taking it further, in certain applications, if the aforementioned 3rd-party filter is cross-referenced against another product from the same company, whose bypass psi is stated as 22-28, is that acceptable?

That would be fine.

Springs are manufactured to a net number. However there is tolerance in all parts on a print it would read + or - a number for allowable variation generally. How tight the tolerance is depends on how much you want to spend $$ on a on a product.

 

[Hootbro]

Some filter makers will list the PSI range from when the valve first begins to open and when it is fully open. If you split the difference between 16-28 PSI, it is 22 PSI.

 

[MarvinTheAndroid]

So by that math, OEM is rated at 22, official cross reference from the 3rd-party mfr is an average of 22, and the one in question from the same 3rd-party mfr is an average of 25. Would that make a real-world difference?

Some filter makers will list the PSI range from when the valve first begins to open and when it is fully open. If you split the difference between 16-28 PSI, it is 22 PSI.

 

[Hootbro]

So by that math, OEM is rated at 22, official cross reference from the 3rd-party mfr is an average of 22, and the one in question from the same 3rd-party mfr is an average of 25. Would that make a real-world difference?

What is your vehicle engine application here? Is the 25 PSI filter you mentioned cataloged for that application? Oil filter makers will not warranty their filters used in applications they do not catalog it for. Does not mean it will not work, but something to consider, especially if you have a vehicle still under a manufacturers warranty.

As to the real world delta of 3 PSI difference, I could not stick my neck out and say it would not unless the filter maker says their application guide says it is kosher. Tolerance stacking and making assumptions can bite one in the rear, especially jumping from filter maker to different filter maker.

 

[ZeeOSix]

So by that math, OEM is rated at 22, official cross reference from the 3rd-party mfr is an average of 22, and the one in question from the same 3rd-party mfr is an average of 25. Would that make a real-world difference?

No real world difference. Trying to out-guess why a filter maker sets a bypass valve to a certain level is a wild goose chase. If you look at 10 different oil filters all specified for the same engine they will have different bypass valve settings because the performance of the filter itself is part of the factor that determines the bypass valve setting. A filter that is more flow restrictive will have a higher bypass valve setting so the filter doesn't go into bypass all the time is one example.

 

[MarvinTheAndroid]

This ties back to the thread I had about possible subs for the Fram 10575. The application I have in mind is my 2017 Traverse (no warranty), but I just replaced the engine out of my own pocket earlier this year, despite taking good care of it. Official is the PF63, and the official Fram cross is 10575.

The 2020 Traverse also calls for the PF63, and official Fram cross is 10575 OR 12750.

The PF63 is rated at 22 psi, 10575 is rated at 16-28 psi, and the 12750 is rated at 22-28 psi.

I'm evaluating if the 12750 could be useful for the 2017 Traverse, since they are plentiful and cheap now.

 

[ZeeOSix]

And on the other end of the spectrum, if a filter bypass valve is set too high then that could cause the oil pump to hit pressure relief sooner and thereby the oil pump will cut back some oil flow the engine. You either have to trust the filter maker has set the bypass valve correctly or not, and if you don't then you'll just go crazy trying to engineer it yourself.

 

[ZeeOSix]

The PF63 is rated at 22 psi, 10575 is rated at 16-28 psi, and the 12750 is rated at 22-28 psi.

I'm evaluating if the 12750 could be useful for the 2017 Traverse, since they are plentiful and cheap now.

Thought you already found info that says they can cross over. The differences between all of those isn't really going to matter because they really aren't that far apart for being different filter models.

 

[Hootbro]

This ties back to the thread I had about possible subs for the Fram 10575. The application I have in mind is my 2017 Traverse (no warranty), but I just replaced the engine out of my own pocket earlier this year, despite taking good care of it. Official is the PF63, and the official Fram cross is 10575.

The 2020 Traverse also calls for the PF63, and official Fram cross is 10575 OR 12750.

The PF63 is rated at 22 psi, 10575 is rated at 16-28 psi, and the 12750 is rated at 22-28 psi.

I'm evaluating if the 12750 could be useful for the 2017 Traverse, since they are plentiful and cheap now.

In the grand scheme of things and everything else you spend money on in life, is it that critical to chase the savings of tracking down and using a non spec filter vs. just buying a filter spec'd for your application?

 

[MarvinTheAndroid]

Well said.

In the grand scheme of things and everything you spend money on in life, is it that critical to chase the savings of tracking down and using a non spec filter vs. just buying a filter spec'd for your application.

 

[MarvinTheAndroid]

Now that the 12750 dead horse is well and truly beaten, going to the other end, I see that Baldwin B7449 is cross referenced for the PF63, as least for my vehicle. But if you look at their specs, they say the bypass valve is set at 20 psi. The TSB's I've seen from GM are really sternly worded as far as the 22 psi setting for new filters. Does the 2 psi difference in this scenario make any real world difference? Another example is the FleetGuard LF17531, whose published spec is 20 psi. I cite them because they're available locally.

 

[ZeeOSix]

^^^ A couple of PSI difference will not matter. If engines were that sensitive half of them would have blow-up on the roads.

 

[MarvinTheAndroid]

Thought I would pass on an interaction I had with K&N about their filters.

What I sent:
Hi there. I am learning as much as I can about your SO-2011 product and evaluating it as a possible solution for my 2017 Chevrolet Traverse. The current spec for this car is the AC Delco PF63/PF63E which these days has a 22 PSI integrated bypass valve. I am concerned that the SO-2011 specifies a range of PSI from 22-28 for its integrated bypass valve. In light of the OEM spec, why was this range of PSI chosen for this product? The other product you specify for my vehicle, the HP-2012, has an entirely different range of 11-17 PSI. Why the difference?

Their reply:
Hi,
The SO-2011 and the HP-2012 fit many different vehicle manufacturers models and engines is why there is a variation in the range of the bypass valve. If your engine requires a specific pressure that is met with the AC Delco filter we recommend that you continue to use that brand of filter.

K&N Tech Support

Sure sounds to me like they're saying, "if you have any concerns or questions about our products, don't use them."

 

[ZeeOSix]

What I sent:
Hi there. I am learning as much as I can about your SO-2011 product and evaluating it as a possible solution for my 2017 Chevrolet Traverse. The current spec for this car is the AC Delco PF63/PF63E which these days has a 22 PSI integrated bypass valve. I am concerned that the SO-2011 specifies a range of PSI from 22-28 for its integrated bypass valve. In light of the OEM spec, why was this range of PSI chosen for this product?

If the K&N bypass spec is 22-28 PSI and the AC Delco is shown as 22 PSI, then 22-28 PSI is fine. Most likely that the bypass valve starts to open at 22 PSI and is fully open at 28 PSI. I think any filter maker showing a range for a fixed bypass valve is just confusing people. They just need to list the cracking open pressure of the bypass valve.