When would you not want an ADBV?
- Thread starter jayjr1105
- Start date
- Status
To understand how the anti-drainback valve works in the first place take a look at this video of a guy cutting some STP filters apart. He cut the end cap off but left the orange anti-drain back valve in position.
Oil flows from the oil pump, into the annulus of the oil filter, (the outside part). It pushes past the anti-drain back valve, enters into the outside chamber of the oil filter, then travels through the media, and then up into the engine. Some people don't realize the flow is into the outside of the filter first, then travels through the media to the inside of the filter.
Oil goes through the oil galleys and lubricates the critical parts. Now. When the engine is shut off, there is a hydrostatic head of oil all the way up to the valvetrain. That oil would want to drain back towards the oil filter. Note: this is the same oil that spills out of the engine when you pull a oil filter off. With no anti-drain back valve the oil would proceed in the reverse direction through the media and would go back to the oil pump and drain back into the sump.
With an anti-drainback valve in postion, that hydrostatic head pushes on the rubber of the drainback valve and seals it against the filter. Oil cannot get buy. When you start the engine next time, there is already existing oil all the way up to highest point in the engine. There are some variations in the design of the galleys. In a Chevy LS engine oil reaches the heads before it travels down to the main bearings, so there is always plenty of oil in those galleys when you pull of the filter, and you get about a 1/2 cup of oil pouring out.
Anyway, look at the anti-drainback valve in position of this video and imagine how the oil pushes the orange valve open to get buy but then when the engine is stopped, the orange valve is pushed shut against the body of the filter and cannot get by. The back pressure valves are shown at 10 minutes into the video.
To answer your question anti-drainback valves are a good thing. No sure why some filters might not have them.
https://www.youtube.com/watch?v=7NSvGNILsf0
Oil flows from the oil pump, into the annulus of the oil filter, (the outside part). It pushes past the anti-drain back valve, enters into the outside chamber of the oil filter, then travels through the media, and then up into the engine. Some people don't realize the flow is into the outside of the filter first, then travels through the media to the inside of the filter.
Oil goes through the oil galleys and lubricates the critical parts. Now. When the engine is shut off, there is a hydrostatic head of oil all the way up to the valvetrain. That oil would want to drain back towards the oil filter. Note: this is the same oil that spills out of the engine when you pull a oil filter off. With no anti-drain back valve the oil would proceed in the reverse direction through the media and would go back to the oil pump and drain back into the sump.
With an anti-drainback valve in postion, that hydrostatic head pushes on the rubber of the drainback valve and seals it against the filter. Oil cannot get buy. When you start the engine next time, there is already existing oil all the way up to highest point in the engine. There are some variations in the design of the galleys. In a Chevy LS engine oil reaches the heads before it travels down to the main bearings, so there is always plenty of oil in those galleys when you pull of the filter, and you get about a 1/2 cup of oil pouring out.
Anyway, look at the anti-drainback valve in position of this video and imagine how the oil pushes the orange valve open to get buy but then when the engine is stopped, the orange valve is pushed shut against the body of the filter and cannot get by. The back pressure valves are shown at 10 minutes into the video.
To answer your question anti-drainback valves are a good thing. No sure why some filters might not have them.
https://www.youtube.com/watch?v=7NSvGNILsf0
Last edited:
From Fram Website:
This might be counter intuitive to some, but oil has to enter through the small holes of the oil filter and force its way past the nitrile diaphragm of the anti-drainback valve as the oil enters the oil filter. Then when the engine is shut off the oil pushes against the diaphragm and shuts off the holes.
You would not need an adbv where the vehicle manufacturer doesn't use one from the factory. That would be some vertical thread end up orientation applications, like Mazda. Interestingly though some GM vehicles come minus adbv with factory filter, however the over counter replacement ACDelco has one. So that aligns with, even where adbv not spec'd from factory, having one never hurts anything. Vice versa, not having one where spec'd, not true.
Originally Posted by jayjr1105
I was looking at some filters and stumbled across a Wix filter made specifically for Mazda Skyactiv engines and it doesn't have an ADBV. Wondering what the pro's and con's are here and what's the harm if you do have an ADBV.
The Pro's oil doesn't leak up!
I was looking at some filters and stumbled across a Wix filter made specifically for Mazda Skyactiv engines and it doesn't have an ADBV. Wondering what the pro's and con's are here and what's the harm if you do have an ADBV.
The Pro's oil doesn't leak up!
Sajac and Johnny and CT8. Read the section from Fram. It's to keep the oil from leaking down from the galleries, not just to keep the oil from leaking out of the filter. A vertical, thread up filter would not help to avoid the leak down from the oil galleries unless it had a anti-drain back valve.
Last edited:
A lot of older, GM engines had no ADBV AND no bypass valve! If the engine is lower on the block than the oil pump (like most older SB Chevy engines), it's difficult to get the siphoning action started to pull the oil backwards through the oil pump into the sump. And, bypass in the block meant the filter didn't need one.
A pressure bypass valve in a block serves the purpose of bypassing pressure if the filter is plugged. For engines without it, the oil filter will have one. The anti-drain back valve serves a completely separate purpose. It is to keep the oil in the galleries from draining back to the pan. Look at the picture of the Fram filter. It has an anti-drain back valve and also a pressure bypass valve. (Also called a pressure relief valve by Fram.)
I get what you are saying Bullwinkle . ( I think you meant the oil filter is bellow the elevation of the oil pump). Perhaps someone can post the oil circulation system for a small block system if might give us a clue on why they did that. I'll post one for an LS engine.
I get what you are saying Bullwinkle . ( I think you meant the oil filter is bellow the elevation of the oil pump). Perhaps someone can post the oil circulation system for a small block system if might give us a clue on why they did that. I'll post one for an LS engine.
Last edited:
Here is the oil system of a Chevy LS engine. Noice the oil goes to the heads before the main bearings. With the engine stopped, oil can stay in the galleries all the way up the heads if a anti-drain back is used.The remaining oil from the heads to the main bearings will bleed off with time.
Last edited:
Well aware of the function and purpose of adbv. Been discussed here many times this sub-forum including all oil gallery info. My answer is accurate as posted and consistent with information posted this subforum over many years. One will find the noted GM vehicles as well topic shown Mazda that spec no adbv on factory filter are vertical thread end up end. No where in my post did I state ALL thread end up applications use no adbv. Honda has some vertical thread end up applications and they do spec an adbv.
Fram actually has an orange can application that's been posted several times this subforum that has no adbv. Been several threads on that application. Linked is one such thread.
https://bobistheoilguy.com/forums/ubbthreads.php/topics/4749537/Fram_EG_with_no_ADBV
Fram actually has an orange can application that's been posted several times this subforum that has no adbv. Been several threads on that application. Linked is one such thread.
https://bobistheoilguy.com/forums/ubbthreads.php/topics/4749537/Fram_EG_with_no_ADBV
Originally Posted by Sayjac
Well aware of the function and purpose of adbv. Been discussed here many times this sub-forum including all oil gallery info. My answer is accurate as posted and consistent with information posted this subforum over many years. One will find the noted GM vehicles as well topic shown Mazda that spec no adbv on factory filter are vertical thread end up end. No where in my post did I state ALL thread end up applications use no adbv. Honda has some vertical thread end up applications and they do spec an adbv.
Fram actually has an orange can application that's been posted several times this subforum that has no adbv. Been several threads on that application. Linked is one such thread.
https://bobistheoilguy.com/forums/ubbthreads.php/topics/4749537/Fram_EG_with_no_ADBV
Yep , no sweat. There are some members who think the reason for a anti-drain back valve just to keep the oil filter from emptying and that a vertical filter takes care of the issue. As we know there is more to it than that. By the way, here is the PH30 for 1968 Camaro with a 327. (Yikes, the Fram site called it a 5.3. Sacrilege!) No anti-drain valve and no bypass valve.
Well aware of the function and purpose of adbv. Been discussed here many times this sub-forum including all oil gallery info. My answer is accurate as posted and consistent with information posted this subforum over many years. One will find the noted GM vehicles as well topic shown Mazda that spec no adbv on factory filter are vertical thread end up end. No where in my post did I state ALL thread end up applications use no adbv. Honda has some vertical thread end up applications and they do spec an adbv.
Fram actually has an orange can application that's been posted several times this subforum that has no adbv. Been several threads on that application. Linked is one such thread.
https://bobistheoilguy.com/forums/ubbthreads.php/topics/4749537/Fram_EG_with_no_ADBV
Yep , no sweat. There are some members who think the reason for a anti-drain back valve just to keep the oil filter from emptying and that a vertical filter takes care of the issue. As we know there is more to it than that. By the way, here is the PH30 for 1968 Camaro with a 327. (Yikes, the Fram site called it a 5.3. Sacrilege!) No anti-drain valve and no bypass valve.
Last edited:
Originally Posted by jayjr1105
Originally Posted by CT8
What is the filters mounting position?
Vertical
![[Linked Image]](https://www.bobistheoilguy.com/forums/attachments/usergals/2020/02/full-82667-41787-screenshot_8.png "[Linked Image]")
Mounted like this the filter will not drain dry but basically sit full of oil till next startup.
ADBV not remotely needed in this orientation.
UD
Originally Posted by CT8
What is the filters mounting position?
Vertical
Mounted like this the filter will not drain dry but basically sit full of oil till next startup.
ADBV not remotely needed in this orientation.
UD
Originally Posted by Snagglefoot
Read the section from Fram. It's to keep the oil from leaking down from the galleries, not just to keep the oil from leaking out of the filter. A vertical, thread up filter would not help to avoid the leak down from the oil galleries unless it had a anti-drain back valve.
Exactly ... there is a lot of oil in the galleries above the oil filter location. Thinking that an ADBV is not needed with base up mounted oil filters is still a big misconception (among others related to oil filters).
Read the section from Fram. It's to keep the oil from leaking down from the galleries, not just to keep the oil from leaking out of the filter. A vertical, thread up filter would not help to avoid the leak down from the oil galleries unless it had a anti-drain back valve.
Exactly ... there is a lot of oil in the galleries above the oil filter location. Thinking that an ADBV is not needed with base up mounted oil filters is still a big misconception (among others related to oil filters).
Originally Posted by UncleDave
Originally Posted by jayjr1105
Originally Posted by CT8
What is the filters mounting position?
Vertical
Mounted like this the filter will not drain dry but basically sit full of oil till next startup.
ADBV not remotely needed in this orientation.
UD
Agree with UD. How would the ADBV in a vertically mounted oil filter at the bottom of the engine stop oil from draining from the galleries? Doesn't make sense. I would say that in this case it doesn't really need one. Basically it's to stop the filter from draining dry when mounted other than in a threads up vertical position.
Originally Posted by jayjr1105
Originally Posted by CT8
What is the filters mounting position?
Vertical
Mounted like this the filter will not drain dry but basically sit full of oil till next startup.
ADBV not remotely needed in this orientation.
UD
Agree with UD. How would the ADBV in a vertically mounted oil filter at the bottom of the engine stop oil from draining from the galleries? Doesn't make sense. I would say that in this case it doesn't really need one. Basically it's to stop the filter from draining dry when mounted other than in a threads up vertical position.
4wd
$50 site donor 2026
Yep … That's going to be the taller side of the hydrostatic U-tube. When I pull a filter off an L83, it takes a quart of oil to refill. That little filter might hold 1/3 of that.
Originally Posted by madeej11
Originally Posted by UncleDave
Originally Posted by jayjr1105
Originally Posted by CT8
What is the filters mounting position?
Vertical
Mounted like this the filter will not drain dry but basically sit full of oil till next startup.
ADBV not remotely needed in this orientation.
UD
Agree with UD. How would the ADBV in a vertically mounted oil filter at the bottom of the engine stop oil from draining from the galleries? Doesn't make sense. I would say that in this case it doesn't really need one. Basically it's to stop the filter from draining dry when mounted other than in a threads up vertical position.
As we have reviewed, the oil filter will not drain, but without a ADBV, the oil in the galleries between the filter and the heads will drain down through the galleries, through the center hole of the filter (in the reverse of the normal direction), and some of oil will be forced by the hydrostatic pressure of the oil in this U-Tube back past the oil pump to the pan. The filter will contain oil but the galleries will be fill with air. Chevrolet seems to think this is important enough to equip oil filters with a ADBV even thought the filters are in the vertical position (threads up). Fram mentions the oil in the galleys in the Fram clipping earlier in the thread.
If you want to argue this is not important to you, that's fine. It is important to GM. When the engine is turned off on a GM LS there is oil stored in the filter and up to heads inside the galleries, ready for the next start.
Note: the terms galleys and galleries are both used to describe the passage ways in an oiling system. Just depends who is doing the writing.
Originally Posted by UncleDave
Originally Posted by jayjr1105
Originally Posted by CT8
What is the filters mounting position?
Vertical
Mounted like this the filter will not drain dry but basically sit full of oil till next startup.
ADBV not remotely needed in this orientation.
UD
Agree with UD. How would the ADBV in a vertically mounted oil filter at the bottom of the engine stop oil from draining from the galleries? Doesn't make sense. I would say that in this case it doesn't really need one. Basically it's to stop the filter from draining dry when mounted other than in a threads up vertical position.
As we have reviewed, the oil filter will not drain, but without a ADBV, the oil in the galleries between the filter and the heads will drain down through the galleries, through the center hole of the filter (in the reverse of the normal direction), and some of oil will be forced by the hydrostatic pressure of the oil in this U-Tube back past the oil pump to the pan. The filter will contain oil but the galleries will be fill with air. Chevrolet seems to think this is important enough to equip oil filters with a ADBV even thought the filters are in the vertical position (threads up). Fram mentions the oil in the galleys in the Fram clipping earlier in the thread.
If you want to argue this is not important to you, that's fine. It is important to GM. When the engine is turned off on a GM LS there is oil stored in the filter and up to heads inside the galleries, ready for the next start.
Note: the terms galleys and galleries are both used to describe the passage ways in an oiling system. Just depends who is doing the writing.
Last edited:
- Status
