Motorcraft Oil Filter Bypass Valve

[jharmon203]

So I have been trying to do a little research with oil filters and I came across the ford promo video/information video on the building of their filters. The advertising for the USCAR-36 requirements. The one thing that sort of stuck out to me was they showed how they redesigned the bypass valve in the filter so that it doesn't touch the dirty side of the filter media. While this sounds excellent in theory, it makes me wonder how on earth it's done.

In a typical filter, the bypass valve is at the end opposite of where the filter contacts the enginer. When pressure builds up in the filter so much that the oil cannot go through the filter, then the bypass valve opens. So how does the bypass valve get enough pressure in the newish designed motorcraft oil filter if it isn't building up pressure against the filter media? Wouldn't this technically create a situation where the filter media is always bypassed? Obviously, this isn't the case or it wouldn't work. However, it still begs the question how the pressure gets built-up if the filter media isn't contacted.

 

[wymi516]

https://www.youtube.com/watch?v=YcJ0pp2pneY

 

[SirTanon]

Originally Posted by wymi516
https://www.youtube.com/watch?v=YcJ0pp2pneY


Good video, and while not specifically about the Motorcraft filters, the bypass valve is the same type that Motorcraft uses. Pertinent details start at 1:50, for those curious.

 

[ZeeOSix]

No matter what kind of design a bypass valve has, they all operate because of the pressure difference (delta-p) across the valve.

The bypass valve will be located either at the threaded base end or in the dome end. Depending on filter orientation, both locations have their advantages.

 

[Job]

OP- good info. When the filter medium resists flow, it goes all the way back to the oil pump. Many cars, like my GM, have bypass installed at the filter mount in the block, no bypass in the filter. Good catch because Ford likes base end bypass and some filter makers still don't support this, like Fram. Some Chrysler also want base end. Pretty sure they have some good hydraulic engineers at those companies.

 

[ZeeOSix]

Originally Posted by jharmon203
So how does the bypass valve get enough pressure in the newish designed motorcraft oil filter if it isn't building up pressure against the filter media? Wouldn't this technically create a situation where the filter media is always bypassed?


There is always delta-p across the filter media when there is oil flow going on. If a bypass valve is set to open at 12 PSI of delta-p, then a very small fraction of flow goes through the bypass valve. The media element is still flowing a huge majority of the flow. Only time all flow would go through the bypass valve is if the filter was 100% clogged. If that happens you have serious issues going on with the engine or not changing the filter forever.

I sense another possible sockpuppet situation starting up again.

 

[CT8]

The media tears to allow the free flow of oil.

 

[IndyFan]

Originally Posted by CT8
The media tears to allow the free flow of oil.


Lol! I just spit my drink on my keyboard.

 

[jharmon203]

Originally Posted by ZeeOSix
No matter what kind of design a bypass valve has, they all operate because of the pressure difference (delta-p) across the valve.

The bypass valve will be located either at the threaded base end or in the dome end. Depending on filter orientation, both locations have their advantages.



What would you say are the advantages of each?

Even in that video I still don't understand how the pressure is getting built up to determine either the oil is cold or the filter media is blocked.

 

[ZeeOSix]

Originally Posted by jharmon203
Originally Posted by ZeeOSix
No matter what kind of design a bypass valve has, they all operate because of the pressure difference (delta-p) across the valve.

The bypass valve will be located either at the threaded base end or in the dome end. Depending on filter orientation, both locations have their advantages.


What would you say are the advantages of each?

Even in that video I still don't understand how the pressure is getting built up to determine either the oil is cold or the filter media is blocked.


You don't really want a base end bypass valve on a filter that mounts straight up vertical with base down.

Like mentioned before ... anytime there is oil flow going through the oil filter there is a pressure difference between the inlet and outlet (across the media). A bypass valve operates solely on the pressure difference across it, which is the same as the pressure difference across the media element. The bypass valve serves to protect the media from damage due to excessive delta-p, and to also ensure oil flow still goes through the filter and to the engine's oiling system.

 

[bullwinkle]

Originally Posted by jharmon203
Originally Posted by ZeeOSix
No matter what kind of design a bypass valve has, they all operate because of the pressure difference (delta-p) across the valve.

The bypass valve will be located either at the threaded base end or in the dome end. Depending on filter orientation, both locations have their advantages.



What would you say are the advantages of each?

Even in that video I still don't understand how the pressure is getting built up to determine either the oil is cold or the filter media is blocked.
Pressure comes in through the outer inlet holes, through the media, and out the center tube. If the oil gets too thick (cold, oxidized, etc.), or the media gets too dirty, the inlet pressure gets higher and the outlet pressure gets lower. If the difference is as big (or bigger) than the bypass valve sewtting, then the bypass opens-whether it's in the dome or on the base end.

 

[DoubleWasp]

That's why I like engines with the bypass in the block. What's in the filter has zero chance of getting out......



........unless the media tears.

 

[jharmon203]

Originally Posted by bullwinkle
Originally Posted by jharmon203
Originally Posted by ZeeOSix
No matter what kind of design a bypass valve has, they all operate because of the pressure difference (delta-p) across the valve.

The bypass valve will be located either at the threaded base end or in the dome end. Depending on filter orientation, both locations have their advantages.



What would you say are the advantages of each?

Even in that video I still don't understand how the pressure is getting built up to determine either the oil is cold or the filter media is blocked.
Pressure comes in through the outer inlet holes, through the media, and out the center tube. If the oil gets too thick (cold, oxidized, etc.), or the media gets too dirty, the inlet pressure gets higher and the outlet pressure gets lower. If the difference is as big (or bigger) than the bypass valve sewtting, then the bypass opens-whether it's in the dome or on the base end.


Ah I see what I am missing here after watching again. There is an initial bit of oil that does touch the filter media to build up the pressure. However, once the bypass valve opens, that initial oil stays where it is and the oil behind it just goes through the bypass. I am sure there is a little bit of mixing, however I believe the concept of not having continual oil go past the dirty filter media is the key here.

It seems like having the bypass towards the screwed end is the most ideal. What situations would it be ideal to have it towards the rounded end?

 

[Job]

Originally Posted by jharmon203
Originally Posted by bullwinkle
Originally Posted by jharmon203
Originally Posted by ZeeOSix
No matter what kind of design a bypass valve has, they all operate because of the pressure difference (delta-p) across the valve.

The bypass valve will be located either at the threaded base end or in the dome end. Depending on filter orientation, both locations have their advantages.



What would you say are the advantages of each?

Even in that video I still don't understand how the pressure is getting built up to determine either the oil is cold or the filter media is blocked.
Pressure comes in through the outer inlet holes, through the media, and out the center tube. If the oil gets too thick (cold, oxidized, etc.), or the media gets too dirty, the inlet pressure gets higher and the outlet pressure gets lower. If the difference is as big (or bigger) than the bypass valve sewtting, then the bypass opens-whether it's in the dome or on the base end.


Ah I see what I am missing here after watching again. There is an initial bit of oil that does touch the filter media to build up the pressure. However, once the bypass valve opens, that initial oil stays where it is and the oil behind it just goes through the bypass. I am sure there is a little bit of mixing, however I believe the concept of not having continual oil go past the dirty filter media is the key here.

It seems like having the bypass towards the screwed end is the most ideal. What situations would it be ideal to have it towards the rounded end?


Whatever way gravity pulls the dirt to the bypass. Base down filters the rounded end is away from settled dirt. Base up thread end bypass is away from settled dirt more. Some companies make both kinds, some do not.

 

[KP_Texan]

Originally Posted by jharmon203
Originally Posted by bullwinkle
Originally Posted by jharmon203
Originally Posted by ZeeOSix
No matter what kind of design a bypass valve has, they all operate because of the pressure difference (delta-p) across the valve.

The bypass valve will be located either at the threaded base end or in the dome end. Depending on filter orientation, both locations have their advantages.



What would you say are the advantages of each?

Even in that video I still don't understand how the pressure is getting built up to determine either the oil is cold or the filter media is blocked.
Pressure comes in through the outer inlet holes, through the media, and out the center tube. If the oil gets too thick (cold, oxidized, etc.), or the media gets too dirty, the inlet pressure gets higher and the outlet pressure gets lower. If the difference is as big (or bigger) than the bypass valve sewtting, then the bypass opens-whether it's in the dome or on the base end.


Ah I see what I am missing here after watching again. There is an initial bit of oil that does touch the filter media to build up the pressure. However, once the bypass valve opens, that initial oil stays where it is and the oil behind it just goes through the bypass. I am sure there is a little bit of mixing, however I believe the concept of not having continual oil go past the dirty filter media is the key here.

It seems like having the bypass towards the screwed end is the most ideal. What situations would it be ideal to have it towards the rounded end?


The advantage of the dome end bypass is that it allows more filter media for a given filter size since it doesn't take up as much length as a thread end bypass.