Bypass Filter Standards?

[Jay Freddy]

I'm kind of a novice at this stuff, but I am trying to wrap my brain around it.

I understand that racing applications generally call for a higher bypass pressure, to insure that motor oil still gets filtered, even when running high revs and operating in higher pressure ranges.

Also, racing motors tend to run very short OCIs, typically before every race, but sometimes more.

Conversely, the OCIs for our daily drivers are fewer and farther between, so there's a greater chance of particles building up and clogging the filter media... So the lower bypass pressure insures that the valve will open and supply oil, which, even if
it's dirty, is generally better than no oil at all, insuring your vehicle gets you and your family safely to your destination.

My question is, if the bypass pressure is such a mission critical feature, why aren't bypass pressures routinely listed as a feature on the outside of the box or label?

I see a lot of comparisons of different filters that include the filter media type, thread type, louvers vs holes, and even bypass filter material (nitrile vs. silicon), but the bypass relief pressure seems to be a secret for most of your everyday filters.

Is there a database somewhere that has bypass pressure numbers for some of the most common filters?

I know, I probably need to get a life and stop worrying about inconsequential details, but I imagine I'm not the only one who's curious.

Thanks in advance!

 

[wpod]

How long do engines last if properly maintained?

 

[SC Maintenance]

The bypass pressure is the pressure drop across the filter media - ie the delta P. So its a function of the entire system - the lubrication system as whole including oil pressure of the engine vs needed flow and the filter design and media. The OEM's set the bypass pressure for the OEM filter presumably - however the filter itself and the pressure required to push oil through the media can be a part of the equation.

So I think the simple answer is the experts have figured out what your particular application needs, and that is why they list that part number specifically for you in their catalog. No need to confuse the issue by listing the bypass pressure because how would you know if it were wrong anyway?

 

[Jay Freddy]

So I think the simple answer is the experts have figured out what your particular application needs, and that is why they list that part number specifically for you in their catalog. No need to confuse the issue by listing the bypass pressure because how would you know if it were wrong anyway?

If a Honda motorcycle prefers an oil filter with a 12 psi bypass valve, wouldn't it make sense to say that in the manufacturer's owners manual?

Usually they simply say, "We recommend Honda brand oil filters..."

Here on BITOG, I doubt the majority of Honda owners are actually using Honda brand oil filters.

It seems easy enough to list a bypass pressure on the box.

Then again, it might simply be a case of, "It doesn't matter."

 

[Jay Freddy]

How long do engines last if properly maintained?

Huh?

I like peanut butter. Can you swim?

I don't follow your reply.

My question is, how come different oil filters don't include the bypass pressures as part of the product description?

They'll happily tell you about the ADBV material, and often the filter media too.
Why the silence over bypass valve pressures?

Is it simply that unimportant?

I can't imagine that to be the case, since here we have an entire forum dedicated to engine oil filters.

Thanks for your patience, and again, thanks for helping me to understand.

 

[ka9mnx]

Racing engines run higher bypass filters because, generally, they run higher oil pressures.

 

[BrendanC]

because if the filter is approved by the manufacturer for your vehicle, the bypass pressure is not an issue. one argument i can already see is subaru oil filters but many have fun a fram 7317 without issue. if you’re that concerned about bypass pressure, the pressures are listed online in the case of fram and purolator.

 

[twX]

Racing engines run higher bypass filters because, generally, they run higher oil pressures.

Another reason is that race engines are prone to failures that can send metal through the oiling system and can destroy most of the engine if the metal clogs the filter and it starts bypassing.

This can happen to street engines too of course, but when it does, it often makes sense to just drop in a new/used engine, so that extra damage doesn't necessarily matter.

Race engines are always rebuilt, and you don't want to replace your expensive custom cams and ported heads just because you spun a rod bearing for instance. Some race engines won't even use a filter bypass.

 

[oil pan 4]

I'm kind of a novice at this stuff, but I am trying to wrap my brain around it.

I understand that racing applications generally call for a higher bypass pressure, to insure that motor oil still gets filtered, even when running high revs and operating in higher pressure ranges.

Also, racing motors tend to run very short OCIs, typically before every race, but sometimes more.

Conversely, the OCIs for our daily drivers are fewer and farther between, so there's a greater chance of particles building up and clogging the filter media... So the lower bypass pressure insures that the valve will open and supply oil, which, even if
it's dirty, is generally better than no oil at all, insuring your vehicle gets you and your family safely to your destination.

My question is, if the bypass pressure is such a mission critical feature, why aren't bypass pressures routinely listed as a feature on the outside of the box or label?

I see a lot of comparisons of different filters that include the filter media type, thread type, louvers vs holes, and even bypass filter material (nitrile vs. silicon), but the bypass relief pressure seems to be a secret for most of your everyday filters.

Is there a database somewhere that has bypass pressure numbers for some of the most common filters?

I know, I probably need to get a life and stop worrying about inconsequential details, but I imagine I'm not the only one who's curious.

Thanks in advance!

Most people wouldn't understand or care what the bypass pressure is. So far every fram synthetic endurance filter I have bothered to look up and could find bypass numbers for have so far always been 11 to 17psid with a target of 12 psid.

If you Google search a filter part number usually you can find the bypass pressure.
Wix lists all their filter bypass numbers if the filter has a bypass on their filter catalog.
Most oil filters run their bypass anywhere from 7 to 17psid. The old standard seems to be more like 7 to 11psid and the newer long duration filter bypasses seem to be more like 11 to 17psid.
20 to 24psid seems to normally be hydraulic filter bypass territory.
Rules for filter bypasses.
1 always run a gd bypass.
2 the best filter bypass is none, ideally your filter head has one built-in so you don't ever need to rely on how cheaply a disposable one can be made.
3 higher psid is generally better, but as psid goes up so does the chances of crushing the filter media.
4 when in doubt go bigger, on the filter that is. Bigger filters do everything better.

 

[dguzzi]

So I see the description is odd. A bypass filter has a finer filter on a bypass loop. A filter bypass is internal to the filter and bypasses the media at a given pressure (like when its having a clogging issue)
Or am I wrong?

 

[oil pan 4]

So I see the description is odd. A bypass filter has a finer filter on a bypass loop. A filter bypass is internal to the filter and bypasses the media at a given pressure (like when its having a clogging issue)
Or am I wrong?

That's pretty much what it does.
A regular single oil filter also likely bypasses some with cold oil too.