anti drain back valve

[LarryL]

Unless a filter is mounded upsidedown is an adbv really necessary? I don't think they really do a good job holding back oil until the next start and in many installations the filter is poing down and then it just looks like it's something to get in the way.

If a filter flows enough it might get pressure up, without an adbv, as quickly a more restrictive filter with the valve.

 

[Jonny Z]

W/O an ADBV, on a hole up filter, the oil line above the filter will be drained to the filter level (filter itself won't be empty)- so an ADBV is still value added

Also, it keeps gunk from back washing to the pan.

 

[LarryL]

If the filter is at a downward angle, the lack of an adbv won't cause oil to be washed back into the pressure side of the oil system. The problem with some filters is the bypass valve opening and washing gunk into the downstream side of the oil system. Basically an adbv is just one more thing getting in the way of oil flow. A bypass valve is for those that don't maintain their engine and/or filters that restrict oil flow on start up and need a more open shot instead of colapsing the element. I'm beginning to think that oil flow is more important than a higher level of filtration. Get rid of both the adbv and the bypass valve.

 

[Filter guy]

LarryL...maybe you should go to an engine company and test your idea's. I'm sure they would appreciate your views.

If you get rid of the adbv and bypass you might as well get rid of the filter. Becuase your oil pump has pressure spikes. These spikes will collapse your filter element. This is one of the main reason you have a by-pass valve. To protect the filter. While everyone discuss the other reason..flow... without a by-pass your filter has a very good chance of collapsing.

To test your theory, go by a GM car with a bypass in the block. Remove it and use a GM filter with no by-pass in the filter. Get back to us..

As far as the anti drainback. Did you ever wonder why engine engineers decided one was needed for any filter mounted inverted to horizontal?

 

[T-Keith]

Almost all GM cars and trucks have the filters somewhere between horizontal and threads up, yet they all have aDBVs. This has been discussed probably 1000000 times. Yes it still matters, no not as much. The ADBV does not pose any great restriction in any filter I've seen. An just like the not getting enough oil thing, it's a positive displacement pump and restriction will not make it take longer to get oil to the engine. The amount of oil in the oil passages and filter determine how quickly that happens.

 

[Gary Allan]

The main reason for the ADBV is to keep the media from backflushing and having stuff migrate in large quantities upon shutdown into the pump gears (sump, etc). Having a lame one isn't all that important/critical as long as it holds long enough or drains slow enough. That's why Fram and the rest of the cheaper component filters aren't sued ..stoned and/or flogged by the engine manufacturers. There are some filters that don't have ADBV ...but I'm sure that they have some characteristic that makes it unnecessary ..as in being built into the engine design.

Although there are plenty of go fast Chebbie engine builders that block off the internal bypass for racing, I think that they really shouldn't. For the assumed safety of assuring that everything gets filtered ...you would pay a dear price in something like a stockcar application where you went around the whole race with no filtration because you had a hole in your filter instead of the brief few seconds that a bypass would be open, IMO.

 

[Islander]

quote:

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Originally posted by Filter guy:
[QB

As far as the anti drainback. Did you ever wonder why engine engineers decided one was needed for any filter mounted inverted to horizontal? [/QB]

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I have a 2004 Chev Cavalier with 2.2L Ecotec engine and the filter is a cartridge type mounted vertically (inlet/outlet on bottom). The filter doesn not have an anti-drainback valve and when I wrote to GM questioning it, they responded in writing advising me that because the oil distribution in the engine is so efficient it has immediate oil pressure and therefore, the anti-drainback valve is not needed.

 

[Beaker74]

quote:

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Originally posted by Jonny Z:
W/O an ADBV, on a hole up filter, the oil line above the filter will be drained to the filter level (filter itself won't be empty)- so an ADBV is still value added.

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If this is true, then the ADBV on my hole up application failed completely. When I removed the filter for an oil change (after draining the oil from the pan) only about a teaspoon pours out around the edges of the filter.

 

[LarryL]

Filter guy is the only one that has it right. The bypass valve is there only to keep the paper from colapsing. And for that you might get gunk washed back into the downstream side of the oil flow that goes to the engine. The adbv is not very efficient and leaks down to the point that it might as well not be there. Anything that flaps around and is in the pressure stream can effect oil flow. On the dyno we've taken a remote mount filter and started the engine right side up and upside down with the filter empty and a mechanical gauge piped in at the far end of the oil system reads pressure in the same amount of time, either way. There may well have been a different amount of time, but we could not detect that small difference by watching and hitting a stop watch.

 

[Filter guy]

LarryL...glad someone agrees with me..lol

There have been discussions before about how long it takes to fill a filter with oil regarding an anti-drainback valve or not.

As you no doubt found out the "time" differential is irrelivant. At the flow rate the oil pump puts out a "dry" filter will fill in a matter of a second. A "wet" filter even less. One with some oil to a full filter..instantaneously.

With a stop watch it would be hard to see a significant difference from all the scenarios..

But some people love to argue the point about fill rates and timing...lol

 

[T-Keith]

quote:

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Originally posted by LarryL:
Filter guy is the only one that has it right. The bypass valve is there only to keep the paper from colapsing. And for that you might get gunk washed back into the downstream side of the oil flow that goes to the engine. The adbv is not very efficient and leaks down to the point that it might as well not be there. Anything that flaps around and is in the pressure stream can effect oil flow. On the dyno we've taken a remote mount filter and started the engine right side up and upside down with the filter empty and a mechanical gauge piped in at the far end of the oil system reads pressure in the same amount of time, either way. There may well have been a different amount of time, but we could not detect that small difference by watching and hitting a stop watch.

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So I must be imagining all the plump full filters I've changed? And that oil gauge that takes 5 full seconds to come up after changing the oil without filling the filters?

 

[kenw]

so when you prefill a filter, what about the empty area between the pump outlet and the filter inlet?

(clue: It's full of air.)

And the area after the filter outlet?

(clue 2: It's full of air.)

Try prefilling a filter on most Toyotas (you can't: they mount holes down, as do others)

we all know how those "dry filters" kills those Toyota engines so prematurely.

 

[brianl703]

I've left filters (Motorcraft FL-820S) to drain for a week holes-down and they STILL had oil in them (which came out when I punched a hole in the dome end and turned them upside down).

In the car that FL-820S is removed from, I've also noticed that removal of the filter results in quite a bit of oil coming out..more than would be accounted for by spillage from the filter itself.

Ford released a TSB for that same car in 1996 about startup noise, which they said would be reduced by usage of the then-new FL-820S filter. (Previously it had a nitrile anti-drainback valve). I somewhat got the impression that Ford changed the FL-820 to use a silicone anti-drainback valve (calling it the FL-820S) just to reduce startup noise on this engine.

Conclusion: The ADBV in the FL-820S is QUITE effective in keeping oil in the filter, and in the engine, and is useful despite the fact that this filter does not mount holes-down.

 

[Jonny Z]

quote:

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Originally posted by Beaker74:

quote:

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Originally posted by Jonny Z:
W/O an ADBV, on a hole up filter, the oil line above the filter will be drained to the filter level (filter itself won't be empty)- so an ADBV is still value added.

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If this is true, then the ADBV on my hole up application failed completely. When I removed the filter for an oil change (after draining the oil from the pan) only about a teaspoon pours out around the edges of the filter.

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On my Toyota 2AZ-FE, I always get splashed with 1/5 to 1/4 of a qt worth of oil when I remove the hole up filter.

 

[Gary Allan]

There's no discounting that a good ADBV will result in a lack of startup noise/rattle in many, if not all installations. The assertion that is unfounded is that the empty filter, due to a lame ADBV, causes any engine damage. I doubt any engine manufacturer has lost any sleep over (surely) knowing that Frams, with their cheaper parts, are allowing their engines to start with empty filters.

What they will lose sleep over is having 48,000 warranty claims for a noisy engine at first start of the day ..at a cost of probably over a million $$ is just lost productivity (data entry).

Startup rattle: Annoying- yes! Damaging ..probably not in any way measurable.

 

[Filter guy]

I sometimes get a kick out of these type threads or questions about the ADBV...

Can you imagine someone in Minneapolis or Edmonton with a standard filter with a buna/nitrile ADBV and not even worrying about whether he has one that is silicon.

Yet his car runs fine and he never notices any particular problem at start up.


Could it be...dare i say... that as an appeasement to some who would complain over anything, that some will claim that a silicon ADBV will solve all your problems.

I suspect the "failure" rate under certain conditions lessens with a silicon ADBV.

But what if every filter sold had a silicon ADBV and still there were some startup noise problems..what then? Do you think engine designers would have to think a little bit harder as to what their engine design contributes to the problem?

 

[T-Keith]

I is easy to argue against something no one said, good job.

-T

 

[brianl703]

quote:

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Originally posted by Gary Allan:
I doubt any engine manufacturer has lost any sleep over (surely) knowing that Frams, with their cheaper parts, are allowing their engines to start with empty filters.

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A rental car company that buys vehicles from Ford is required by Ford to use Motorcraft oil filters; if they do not, Ford will not buy the vehicle back from the rental car company.

I wonder why that is. Is Ford concerned about poor quality oil filters????

 

[kenw]

quote:

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Originally posted by brianl703:

quote:

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Originally posted by Gary Allan:
I doubt any engine manufacturer has lost any sleep over (surely) knowing that Frams, with their cheaper parts, are allowing their engines to start with empty filters.

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A rental car company that buys vehicles from Ford is required by Ford to use Motorcraft oil filters; if they do not, Ford will not buy the vehicle back from the rental car company.

I wonder why that is. Is Ford concerned about poor quality oil filters????

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no, it's called supporting the parts division.

 

[brianl703]

..because they make so much off of filters bought at wholesale prices from a Motorcraft distributor...