One very good filter question!!!!!!!!!!!!

[vad]

quote:

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Originally posted by dbvettez06:
Is there a point where a filter can over filter the oil, and not flow properly? I know there is a huge difference between a wal mart fram and , say a k/n oil filter....Yes, i am a newby, have patience.

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A difference between a Fram and K&N is not that huge, well, in price maybe.
The most of the name brand oil filter will easily last 20K miles and beyond in the modern, properly maintained engines.

 

[labman]

Don't tar Wal-Mart with the Fram brush. Many other retailers are guilty of selling them too, sometimes as their only brand.

The bypass pressure is set by the engine manufacturer. The filter manufacturer than builds different filters to meet the different specs. Of course, each filter is built to withstand the bypass specified.

 

[Winston]

This is one of the best discussions on this topic I have seen here. All the heavyweights have chimed in.

We've got the home experimenter.

We've got the oil blender.

We've even got the oil filter engineer.

Gary never sees much of a psi drop accross his filter set-up. However, he has a bunch of miles on that engine and it really is not a hot rod.

I wonder if the new Honda civic, when reved to the 8500rpm redline would cause the Wix bypass to open when the filter is brand new and the oil is at operating temp(190F)? Just curious. I think someone out there knows the answer.

 

[Winston]

Hey, Gary I did not mean to argue with you. I really think your experiments are very usefull and believable. Based on your experiments I am convinced that that even the most "supposedly" restrictive filters (Pure One) do not have any significant restriction. I also believe that the bypass valve hardly ever opens in a filter. I also believe that todays modern quality filters never approach a condition where they get significantly "loaded".

However, I do have a nagging question in my mind regarding high rpm operation. The old GM engineer here recommended not getting into the high rpm range when breaking in a motor because the bypass valve in the filter will open. I think that guy knew his stuff pretty well, so I think that in SOME engines that bypass valve may open more frequently than in other engines. I am just trying to learn which engines that may be (if any). So, I took the most extreme (but still common) example I could think of off hand. It seems like it would be very difficult to design an oil system (with filter) that did not go into bypass at 8500 rpms. I don't consider a Civic to be a fire breathing dragon.

Just trying to gather more data.

 

[Gary Allan]

No ..non...no, pal

I hope that I didn't have a arguementitive tone there ..with you anyway...


You are perhaps correct. I cannot simulate those conditions in my 3.0. I cannot achieve the rpms and, even if I did, I don't know the volume of the other engines in comparison

I would think that, in the case of the aforementioned dragons (whether fire breathing or of the "puff the magic" variety

) that the instances of bypass operation will be "transitional". That is, this is my opinion. Again, one can assume that the oil is somewhat near operating temp and that it presents, at least within its viscosity range, as little (or near as little) resistance to motion as it can. This should (or at least I reason) be equivalent to lower flow rates with higher viscosities (if you see what I'm saying here).

I can surely be wrong ...I've been wrong at least once in my life (if I can only remember when that was

= Alzheimer's to the rescue

) ..but I would think that everything in regards to bypass operation would have some conversion factor for a constant or continuous flow situtation. In the transitional state is where you could see issues that I observed ...which I can only describe as "inertia" ...where the change in status (either from totally still or changing from one flow state to another in an abrupt manner timewise) creates a temporary "surge" or para-"bellows" effect. (again - if you can tune into my oddball view here

).


I'm surely open to the "duality" of a bypass valve. We can surely see that it may work in high visc/low temp settings (I almost reached it) ..and we can see that PSID does indeed increase as a filter is used ...but that it would take many miles to make bypass valve use routine (this may not be the case for all cars in typical usage - no one here is typical). So ..why not say that it also functions as a safety in these transitional states in high rpm situations?

[ April 10, 2006, 04:28 PM: Message edited by: Gary Allan ]

 

[Gary Allan]

Sure, Winston

There are surely situations where a bypass will open. You'll note that, as far as the vast majority of drivers are concerned, you're in "Bigfoot" range here. The term I use merely depicts a very obscure set of circumstances that is a fraction of the total picture.

My view merely sits on the largest part of real estate in that vista.

Again, regardless of whether my engine has many miles or few miles on it, my flow is identical to some rate of flow at some point in just about any engine. My pressure (which is decent - 80psi cold) is somewhere in the range at some point in just about all engines as it transitions from cold to hot ...as, and as a result of, viscosity. At some point I should span the majority of the full spectrum of conditions with decent coverage.

Is it a comprehensive evaluation? No, but due to the lack of response from the bypass valve in all but extreme conditions, it highly suggests that this is a minor matter for most of us that perceverate upon the topic.

I'm open to suggestions from anyone who scoffs at my opinion that would allow them to see either what they want to see ...or not

I feel, however, it will take us to "Bigfoot" range.

"Well, once I was watching a fire breathing dragon on the chassis dyno and when the guy shifted @ 9k rpm @ peak hp the PSID blipped into the bypass setting"

That's a Bigfoot sighting in my book. The majority of the planet's occupants will never see it no matter how hard they try.

 

[dbvettez06]

Thanks for the input, this is quite a forum!!

 

[Gary Allan]

I may be looking at this from the wrong angle. Let me state this in a way that my cause a little more agreement.


Regardless of what a bypass setting is, the media must be able to withstand the differential. Hence, PureOne has to have a more substantial media then Wix in most common filters. Both WIX and Purolator offer VW/Audi filters with 30 psi bypass valves. These medias must be substantially stronger to operate under that pressure differential.


So (thinking of the term "although a square is a rectangle ..a rectangle is not always a square - or some variant of that line of thinking), although the bypass valve may not specifically be intended to protect the media, its rating is directly related to media strength/durability to withstand pressure differentials.

I think we can agree that it is a major co-function of its use.

dbvettez06 - yes, this is quite a forum ...and this topic has nagged at us for as long as I've been here. Even when we attempt to prove or disprove stuff ....it only leads to more questions. This, generally, is a good thing ..from a "quest for fire" type standpoint ..but it sure gets a thermal component to it from time to time

 

[Papa Bear]

Question....when a filter goes into bypass mode, does the crap that has accumulated in the can get "washed out" with the bypass or does it stay in the can ??
I drove a '76 VW beetle for about 160k miles until the floor rotted out in our salty Canadian winters. The beetle didn't even have a filter and the engine ran very well on it's trip to the salvage yard.
As with most things in life, it's a compromise. There are few RIGHT answers and many BETTER answers. I see the filter bypass as the BETTER answer.

P.B. (still smoke free in '06)

 

[wavinwayne]

In theory, with the threaded end bypass filters, the crud stays put. With the dome end bypass filters, the crud can wash back into the engine. Like I said, in theory.

 

[Papa Bear]

How is your expy door coming, WW ??

 

[BearZDefect]

Let's see if I've learned something in this BITOG forum:

1. In many engines the oil pump bypass will open around 3k rpm so effective oil pressure in the oiling system past that bypass is about the same at 3k as 6k rpm.

2. Even with a dome end bypass, when the bypass is open there is still flow through the media so the trapped dirt isn't suddenly backwashed through the media. More likely it stays put, assuming there isn't an overflowing volume of debris in there.

Pass or flunk?

 

[wavinwayne]

P.B.,

I've prepped the new door for installation. Now I have to pull the wiring harness out of the existing door, so I can install the new door. I've got to bolt on the new door, line it up, re-run the wires, & I'll be done. Looks like my Saturday project. I'll be selling the damaged door in pieces if anyone is interested.

 

[Gary Allan]

I'm not so sure about #1. If you can say that 3k HOT the pressure is no different then max cold pressure ..then sure. Otherwise it doesn't flush. The pressure relief will be at or greater then max cold pressure. If you do not reach peak cold pressure ..you cannot be at the pressure relief point.

#2 I agree with. The amount of flow bypassing the media is very slight. It's not like you're opening a gate in a levy.

 

[BearZDefect]

Let me clarify that in #1 the only bypass I was referring to was the internal bypass of the engine, that could be set around the range of 80 psi from examples I've seen here. I realize that some engines will continue to increase pressure to higher speeds than 3k rpm.

In #2 I referred to the filter bypass only.