How Often Do Filter Go Into Bypass Mode?

[JerryBob]

I recently watched a Fram video where they tested the bypass valve, and I understood them to say that the valve kicks in very frequently.

I was always under the impression the the BPV was there only as a fallback should the filter get too clogged to flow.

But it sounds like bypass is normal during very cold starts, especially with thick oil.

I guess there is no way for the average owner to know if or when their filter is in bypss mode. It would be interesting if there was some sort of instrumentation to indicate the filter mode.

 

[Ramblejam]

https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=3067617#Post3067880

 

[JerryBob]

Once again, Jim Allen more than answered my question

 

[dnewton3]

Not only does his answer help, but his actual field testing confirms it. Testing data outweighs verbal supposition, but when they actually agree (real world performance confirms design theory), you really cannot argue with it.


In short, the bypass RARELY opens, and even when it does, it is typically measured in fractional seconds.

This is, of course, presumed to be in a "normal" situation and not one of total neglect where the media is blinded off. But, given the capacity of any typical filter, and the clean running nature of engines over the last few decades, this is a moot point. Only a combination of total neglect AND an engine in poor state experiencing, heavy contaminat intrusion, would ever be at risk for this condition. Few people en-mass ever let this happen, and I cannot conceive of any BITOGer ever coming even remotely close to this.

Quit worrying about it.

 

[Motorking]

Jerrybob,
Thanks for watching my video. I think your taking it the wrong way. When we say frequently, it will always open on engine start up untill the oil is fluid enough to go through the filter cartridge. How long does it take? depends on ambient temperature. Can be milliseconds when it is warm outside and up to 30-60 seconds in sub zero weather. It also may bypass at max engine rpm depending on how much oil pressure and flow the particular engine makes at max rpm.

 

[JerryBob]

Originally Posted By: dnewton3

Quit worrying about it.



Who's worried? I am just trying to educate myself, and learn how all this stuff works. I have been a woodworking geek for that last 30 years. Now I am getting interested in cars.

Watch out!

 

[ZeeOSix]

We gotta train another newbie ...

J/K

 

[turtlevette]

What about plugging the bypass in the oil filter adapter on the engine block? I got into a huge fight on a corvette forum telling someone that was a really bad idea.

If all filters have an internal bypass, I guess it doesn't matter.

 

[Sayjac]

Originally Posted By: turtlevette
...If all filters have an internal bypass, I guess it doesn't matter.

Not all do, particularly many/most GM applications. They have an engine block bypass.

And you are correct, disabling the engine block bypass is a dumb idea.

 

[ZeeOSix]

Originally Posted By: turtlevette
What about plugging the bypass in the oil filter adapter on the engine block? I got into a huge fight on a corvette forum telling someone that was a really bad idea.

If all filters have an internal bypass, I guess it doesn't matter.


Filters specified for the LS Vette engines do not have their own bypass valve. And yes, plugging the filter bypass valve built into the engine block is a bad idea. If the delta-p across the filter became too great it can damage the internals of the filter, and that in turn could damage the engine.

I really don't know the background on why "racers" thought it was a good idea to disable the bypass valve on GM engines. They probably thought it gave them 20 more HP.

You don't happen to have the link to that discussion thread, do you? If so, I'd like to read it.

 

[turtlevette]

Originally Posted By: ZeeOSix
[I really don't know the background on why "racers" thought it was a good idea to disable the bypass valve on GM engines. They probably thought it gave them 20 more HP.

It was some guy who builds engines up in Maine. He thinks if the engine has a failure of some type all the metal shavings will be caught in the filter.

 

[BlueOvalFitter]

Originally Posted By: ZeeOSix
I really don't know the background on why "racers" thought it was a good idea to disable the bypass valve on GM engines. They probably thought it gave them 20 more HP.

Z06, you and I both know that by adding race decals to the vehicles body or windows will only give you extra HP.

 

[novadude]

Originally Posted By: turtlevette
Originally Posted By: ZeeOSix
[I really don't know the background on why "racers" thought it was a good idea to disable the bypass valve on GM engines. They probably thought it gave them 20 more HP.

It was some guy who builds engines up in Maine. He thinks if the engine has a failure of some type all the metal shavings will be caught in the filter.



I've given up having that discussion on "enthusiast" forums.

I'd much rather have a bypass valve and deal with a bit of dirty oil, than to run a blocked bypass and sacrifice oil flow to the bearings, etc in situations where the bypass would normally operate. Seems like most of these guys want to argue that the filter flows plenty in ALL situations. If that was the case, why not just leave the bypass open - it would never open anyway, right?

You'll never win that battle (particulaly with the guy you are referring to in Maine).

 

[Clevy]

Originally Posted By: novadude
Originally Posted By: turtlevette
Originally Posted By: ZeeOSix
[I really don't know the background on why "racers" thought it was a good idea to disable the bypass valve on GM engines. They probably thought it gave them 20 more HP.

It was some guy who builds engines up in Maine. He thinks if the engine has a failure of some type all the metal shavings will be caught in the filter.



I've given up having that discussion on "enthusiast" forums.

I'd much rather have a bypass valve and deal with a bit of dirty oil, than to run a blocked bypass and sacrifice oil flow to the bearings, etc in situations where the bypass would normally operate. Seems like most of these guys want to argue that the filter flows plenty in ALL situations. If that was the case, why not just leave the bypass open - it would never open anyway, right?

You'll never win that battle (particulaly with the guy you are referring to in Maine).



Dirty oil?
Just how dirty do you think the oil can be?
The by-pass event discussions crack me up when the fear mom gets are fretting over unfiltered oil running through their engines.
Let's really think about this.
The oil in the pan is very clean considering it's only gone through the engine once since being filtered. Now if it's so cold that the by-pass opens for a minute or even 2 minutes then that oil has been pumped through the engine maybe 5 or 6 times.
Now unless you've got a seriously sludged up dirty engine or are doing some kind of flush with an additive how dirty is that oil in reality before the by-pass closes and the oil is getting filtered again.

My compressors run for 100 hours in the dustiest dirtiest conditions all day and when I change the oil it's free from any real grit and particulate,so a minute or 2 in my car is absolutely nothing to even give a second thought to.

 

[ZeeOSix]

Originally Posted By: turtlevette
Originally Posted By: ZeeOSix
I really don't know the background on why "racers" thought it was a good idea to disable the bypass valve on GM engines.


It was some guy who builds engines up in Maine. He thinks if the engine has a failure of some type all the metal shavings will be caught in the filter.


As mentioned before, if the bypass valve never really opens much anyway - and it shouldn't unless the oil is pretty cold with high engine revs - then he's really got nothing to worry about. If I had a race car I'd also be using a full synthetic filter to take advantage if their better flow capability.

I'd worry more about the guts of the filter becoming damaged if there was too much delta-p because of no bypass valve, and that in turn causing some kind of flow restriction and engine failure. Also, as you mentioned, no bypass valve could cause oil flow to the bearings to be less if the delta-p across the media was much higher than the bypass valve's normal opening pressure.

Besides, if there's an engine failure where there are kinds of metal shavings going everywhere, then he's got more problems to worry about than if some of those went through the bypass valve.

 

[JiL]

Originally Posted By: Clevy
Just how dirty do you think the oil can be?
. . .
The oil in the pan is very clean considering it's only gone through the engine once since being filtered.

My concerns are less about sump oil being filtered or not and more about the contaminants and debris that has been sequestered on the dirty side of the filtereing element being released en masse during a bypass event.

 

[SilverC6]

Originally Posted By: Motorking
Jerrybob,
Thanks for watching my video. I think your taking it the wrong way. When we say frequently, it will always open on engine start up untill the oil is fluid enough to go through the filter cartridge. How long does it take? depends on ambient temperature. Can be milliseconds when it is warm outside and up to 30-60 seconds in sub zero weather. It also may bypass at max engine rpm depending on how much oil pressure and flow the particular engine makes at max rpm.


Sounds like there may be some differing opinions here.

So the bypass always opens at start up and remains open until the oil can cycle through the filter normally.

In the summer, that may take less than a second.

On a week with temperatures in single digits, that may be a minute or two.

That doesn't sound like a rare occurrence at all.

 

[ZeeOSix]

Originally Posted By: JiL
Originally Posted By: Clevy
Just how dirty do you think the oil can be?
. . .
The oil in the pan is very clean considering it's only gone through the engine once since being filtered.

My concerns are less about sump oil being filtered or not and more about the contaminants and debris that has been sequestered on the dirty side of the filtereing element being released en masse during a bypass event.


When an oil filter goes into bypass, there is still flow also going through the media unless the media is 100% blocked. If that's the case, you go more problems then letting a little dirty oil through the bypass.

Anyway, with oil still going through the media, it will keep any debris in the pleats pinned up against the media and highly unlikely any already trapped particles in the media would get through the bypass valve.

However, if debris falls off the media while the engine is off, and collects in the dome end, and if the orientation of the filter is right then it's possible debris laying in the dome end could be swept through the bypass valve.

This is basically why Ford put the bypass valve in the base end of the filter, because many of their oil filters sit with the base up and the filter at about a 45 deg from vertical.

 

[dnewton3]

What I love to point out is that there really isn't any reason to give a darn, and here's a detailed reason as to why ...
(for this discussion we are going to presume a healthy engine and a filter that is not neglected ...)

There are only two possible answers the the following question:
How often does the filter media get bypassed?
1) a great deal of the time; happens every day in nearly all temps
2) hardly happens at all; regardless of temps

Why my non-chalant attitude? Because WEAR DATA AND ENGINE LONGEVITY tell us it does not matter.

I would like someone to show me conclusive data that for any given situation, the statisically significant engine damage, wear and destruction from frequent BP events.
If you contend that BP events are common, I can accept that. But does it manifest into actual wear data that shows a propensity for concern?
If you contend that BP events are rare, then how much concern should you have for something that hardly ever happens anyway?

You see, ladies and gentlemen, wear data is what you should care about, not if a filter occasionally burps fluid around the valve.

I like the BP valve; it is there for a very good reason. It is there to protect the media from damange, as well as assure a very minimal (if non-existent) disturbance in volumetric flow. I really don't care how often it opens, as long as it protects my filter and engine simultaneously.


In my Dmax engine, I have used 15w40 and conventional 10w30 lubes. I have seen a small but identifiable difference in start up pressure when uber-cold outside (such as the impending sub-zero starts we anticipate this week). I'm completely confident that the BP will function as appropriate when needed. But does that matter at all to the engine wear? Nope! When I study data from Dmax engines in the far south (which RARELY EVER see cold temp starts) and then compare it to data from units in the far north (Canada and upper plains States), I don't see any statistically significant difference in wear data that would suggest bypass events make any difference whatsoever. Same goes for the 4.6L Mod Ford motor. The data shows that inferred BP events based upon time and temp just don't manifest into wear data deltas. The worst-case situtations in the uber cold (presumably BP happens often at a cold start and lasts a minute or two until the oil is warm enough to close the BP valve) do not show any wear uptick versus those from the very warm areas (FL and AZ, where presumably the BP rarely ever opens and only for a fraction of a second with thinner lubes).

Wear is first attenuated by the tribochemical barrier, followed up immediately by the hydrodynamic film wedge. As long as those are intact, the rest is moot. It is very important to have a BP feature, but how often and how long that event happens should not be of concern. Between Jim Allen's BP event testing and my analysis of over 10,000 used oil analysis, I'm pretty darn confident that as long as the BP valve is functioning, it really does not matter.


Or, for those who prefer the Cliff-Note version:
As long as the BP is present and working, it does not make a flippin' difference how often and how long it happens.



If you doubt my position, or have conflicting data, then by all means, bring it forth for us to review. I ask that you PROVE your position with real hard data, and not conjecture based upon some hypothesis.

 

[SilverC6]

I would then gather that a small filter defect that permits some slight bypass, like the small media tears we are seeing in Purolator filters, would have the same neligibile effect upon wear and engine longevity.