Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

ProVent filter cleaning - how?

Thread Tools
 
Search this Thread
 
Old 08-13-2014, 06:23 AM
  #1  
kurt_1
Instructor
Thread Starter
 
kurt_1's Avatar
 
Join Date: May 2001
Location: Germany
Posts: 154
Likes: 0
Received 2 Likes on 1 Post
Default ProVent filter cleaning - how?

Stupid question maybe, but how are you cleaning your filter element of the ProVent?

There is some oil saturation so I'd like to clean it out. I tried alcohol and K&N air filter cleaner but that didn't work well. Simple gasoline might do the trick but I am not sure if that doesn't damage the filter.

Any pointers greatly appreciated!

____
Kurt
90 S4 satin black metallic
928 OC Charter Member
Old 08-13-2014, 10:22 AM
  #2  
Ducman82
 
Ducman82's Avatar
 
Join Date: Nov 2009
Location: Marysville WA
Posts: 6,981
Received 18 Likes on 11 Posts
Default

that filter medium is not meant to be cleaned. it needs to replaced.
Old 08-13-2014, 10:46 AM
  #3  
andy-gts
Drifting
 
andy-gts's Avatar
 
Join Date: Aug 2006
Location: lawrence,kansas
Posts: 2,232
Likes: 0
Received 12 Likes on 11 Posts
Default

do a search for "good deal on provent filters" got mine there and they were 25 dollars each...
Old 08-13-2014, 12:01 PM
  #4  
kurt_1
Instructor
Thread Starter
 
kurt_1's Avatar
 
Join Date: May 2001
Location: Germany
Posts: 154
Likes: 0
Received 2 Likes on 1 Post
Default

Originally Posted by andy-gts
do a search for "good deal on provent filters" got mine there and they were 25 dollars each...
Lucky you guys over there! The best deal I could find here was the equivalent of about 70 dollars! The fact that they are made here doesn't mean they are cheap...

If it is only oil that "contaminates" them, why can't they just be cleaned with a suitable solvent?

Edit: just found a spec sheet from Mann Hummel (https://www.mann-hummel.com/fileadmi...nt_en_2013.pdf),

On the specs-page (page 20) they say it's resistant against oil (obviously) petrol, diesel and "cleaning agents" (whatever these are).
I guess cleaning it with petrol should be OK then?.

____
Kurt
90 S4 satin black metallic
928 OC Charter Member

Last edited by kurt_1; 08-13-2014 at 12:32 PM.
Old 08-13-2014, 12:27 PM
  #5  
Ducman82
 
Ducman82's Avatar
 
Join Date: Nov 2009
Location: Marysville WA
Posts: 6,981
Received 18 Likes on 11 Posts
Default

you have the white cloth and under it is the absorbent matrix. how saturated is it getting to the point that you need to clean in? is it not draining the oil?
Old 08-13-2014, 12:53 PM
  #6  
kurt_1
Instructor
Thread Starter
 
kurt_1's Avatar
 
Join Date: May 2001
Location: Germany
Posts: 154
Likes: 0
Received 2 Likes on 1 Post
Default

Originally Posted by Ducman82
you have the white cloth and under it is the absorbent matrix. how saturated is it getting to the point that you need to clean in? is it not draining the oil?
Judging from the stains on the white cloth, the bottom third of the matrix is saturated with oil.
It probably still works as intended but my OCD makes me want to clean it :-)

____
Kurt
90 S4 satin black metallic
928 OC Charter Member

Last edited by kurt_1; 08-13-2014 at 02:19 PM.
Old 10-25-2018, 12:44 PM
  #7  
davek9
Rennlist Member
 
davek9's Avatar
 
Join Date: Jul 2006
Location: Bloomfield, MI
Posts: 5,111
Received 324 Likes on 177 Posts
Default

Checking my Provent filter after the Frenzy trip, I see that it is about 3/4 saturated
I know that they really can't be cleaned, wondering if anyone has had success without just replacing them?

Searching I see that a new Stainless Steel mesh version (cleanable) is now on the Market, was think of of giving one a try, anyone using one?
I know that my CC venting on my Twin Screw needs a bit of reworking (larger piping, and some rerouting) and will do so over this winter, but looking ahead at reusable filters.

Thanks,

Dave K
Old 10-25-2018, 02:06 PM
  #8  
FredR
Rennlist Member
 
FredR's Avatar
 
Join Date: Jun 2005
Location: Oman
Posts: 9,700
Received 664 Likes on 541 Posts
Default

Gents,

I have a feeling the concept involved in the Pro Vent may not be understood or at least not understood the way I believe it works. The bigger particles of oil are knocked out by centrifugal force as the gas spins around the tangential chamber. This however does not drop out all the oil and a mechanism to do so is required.

The element is not a filter per se, rather it is a coalescing screen designed to give the oil mist something for the residual smaller particles of oil to coalesce on [i.e. stick together and thus form droplets big enough to fall out of the gas stream and collect for recovery. The manufacturers literature suggests it is OK for 1000 hours of use before replacement- it also states to change it out after a year of operation but frankly I suspect that is nonsense- just a commercial grab as it were. I have never seen any evidence on my screen that it needs replacing but then I do not do a whole of run hours either.

Perhaps the OP can clarify why he feels he has a problem that needs a solution.
Old 10-25-2018, 05:34 PM
  #9  
GregBBRD
Rennlist
Basic Site Sponsor
 
GregBBRD's Avatar
 
Join Date: Feb 2005
Location: Anaheim
Posts: 15,219
Received 2,451 Likes on 1,459 Posts
Default

Originally Posted by FredR
Gents,

I have a feeling the concept involved in the Pro Vent may not be understood or at least not understood the way I believe it works. The bigger particles of oil are knocked out by centrifugal force as the gas spins around the tangential chamber. This however does not drop out all the oil and a mechanism to do so is required.

The element is not a filter per se, rather it is a coalescing screen designed to give the oil mist something for the residual smaller particles of oil to coalesce on [i.e. stick together and thus form droplets big enough to fall out of the gas stream and collect for recovery. The manufacturers literature suggests it is OK for 1000 hours of use before replacement- it also states to change it out after a year of operation but frankly I suspect that is nonsense- just a commercial grab as it were. I have never seen any evidence on my screen that it needs replacing but then I do not do a whole of run hours either.

Perhaps the OP can clarify why he feels he has a problem that needs a solution.
Once the filter gets saturated with oil, it no longer flows as much air and needs to be replaced.

On GTS engines, (with my oil control system), which have been passing large quantities of oil, for years, it can take several filters before the rings get "happier".

It is Mann part number LC5001X.
Old 10-26-2018, 05:57 AM
  #10  
FredR
Rennlist Member
 
FredR's Avatar
 
Join Date: Jun 2005
Location: Oman
Posts: 9,700
Received 664 Likes on 541 Posts
Default

Originally Posted by GregBBRD
Once the filter gets saturated with oil, it no longer flows as much air and needs to be replaced.

On GTS engines, (with my oil control system), which have been passing large quantities of oil, for years, it can take several filters before the rings get "happier".

It is Mann part number LC5001X.
Greg,

That the "Separation element" does not flow as much blow by gas when it is oil saturated should come as no surprise- the question is "what does it flow at what pressure drop" when saturated? Given what it is designed to do oil saturation should be considered part of normal operation or so I would think.

The Pro Vent 200 gets is name from the fact that it is rated to flow 200 litres/min at design conditions -not when new or so I would expect. This is based on some correlation that an engine that produces 250kW [330 BHP] should generate that amount of blow-by gas. Obviously if an engine is in poor condition it may well generate significantly more blow by gases and perhaps [in the case of the GTS?] lift more oil. Such criteria will reduce the life span of the unit but to what extent?

Your description of changing the separation unit "several times" with your system is interesting. You have obviously concluded somehow that you need to do this and it would be interesting to know how you concluded such if you feel able to share such info. You make this sound more like what I refer to as "a commissioning spare" i.e. a transient requirement as in the element needs replacing every few hours during the initial operational period. Whereas this may well work for you it certainly does not sound anything like how the designers intended it to be used. Put another way, your case makes it seem like the unit is too small for the intended use. That in itself is interesting because I seem to remember one of our more prominent community opined some time ago that this unit was too small. Cannot remember who it was but I have a feeling it may have been Colin J [Lizard] . Whether or not the 400 unit can be fitted in the available space remains to be seen- a bit tight I suspect and that with my twin fan unit creating more space.

I have my unit plumbed to a sealed catch bottle - the original intent being to see how much oil it actually caught which turned out to be next to nothing so just left it there. This may be down to the amount of oil taken out in my filler neck baffle- one of the ones designed by John Kuhn with the inserted wire mesh. My current results suggest the Pro Vent may not be needed but then I am left wondering whether the crankcase pressure is too high . I am still using some oil but not as much as I was previously. Another possibility is to try one of your baffle plates to see what happens then.

Bottom line the Pro Vent separation element should be able to run for a considerable number of run hours [i.e. hundreds] without being changed. Their target of 1000 hours may be optimistic [I am always suspicious of nice round numbers] but to my way of thinking if one cannot run with them for many hours without issue then it is not worth having. It will catch any crap that is blown out in the gases but if oil accumulation is perceived to be a problem then to my way of thinking something would be wrong.
Old 10-26-2018, 03:27 PM
  #11  
GregBBRD
Rennlist
Basic Site Sponsor
 
GregBBRD's Avatar
 
Join Date: Feb 2005
Location: Anaheim
Posts: 15,219
Received 2,451 Likes on 1,459 Posts
Default

Originally Posted by FredR
Greg,

That the "Separation element" does not flow as much blow by gas when it is oil saturated should come as no surprise- the question is "what does it flow at what pressure drop" when saturated? Given what it is designed to do oil saturation should be considered part of normal operation or so I would think.

The Pro Vent 200 gets is name from the fact that it is rated to flow 200 litres/min at design conditions -not when new or so I would expect. This is based on some correlation that an engine that produces 250kW [330 BHP] should generate that amount of blow-by gas. Obviously if an engine is in poor condition it may well generate significantly more blow by gases and perhaps [in the case of the GTS?] lift more oil. Such criteria will reduce the life span of the unit but to what extent?

Your description of changing the separation unit "several times" with your system is interesting. You have obviously concluded somehow that you need to do this and it would be interesting to know how you concluded such if you feel able to share such info. You make this sound more like what I refer to as "a commissioning spare" i.e. a transient requirement as in the element needs replacing every few hours during the initial operational period. Whereas this may well work for you it certainly does not sound anything like how the designers intended it to be used. Put another way, your case makes it seem like the unit is too small for the intended use. That in itself is interesting because I seem to remember one of our more prominent community opined some time ago that this unit was too small. Cannot remember who it was but I have a feeling it may have been Colin J [Lizard] . Whether or not the 400 unit can be fitted in the available space remains to be seen- a bit tight I suspect and that with my twin fan unit creating more space.

I have my unit plumbed to a sealed catch bottle - the original intent being to see how much oil it actually caught which turned out to be next to nothing so just left it there. This may be down to the amount of oil taken out in my filler neck baffle- one of the ones designed by John Kuhn with the inserted wire mesh. My current results suggest the Pro Vent may not be needed but then I am left wondering whether the crankcase pressure is too high . I am still using some oil but not as much as I was previously. Another possibility is to try one of your baffle plates to see what happens then.

Bottom line the Pro Vent separation element should be able to run for a considerable number of run hours [i.e. hundreds] without being changed. Their target of 1000 hours may be optimistic [I am always suspicious of nice round numbers] but to my way of thinking if one cannot run with them for many hours without issue then it is not worth having. It will catch any crap that is blown out in the gases but if oil accumulation is perceived to be a problem then to my way of thinking something would be wrong.
Fred:

I really don't' pay too much attention to claims by people or manufacturers, but rely on my own testing and observations.

There is little doubt, in my mind, that the Provent 200 is marginal for the 928 application, especially in engines that have high blowby and the resulting severe oil consumption. I've found that these engines will initially have significantly reduced oil consumption (with my plumbing and pieces), but as soon as the filter becomes completely covered with oil, the oil consumption will increase again. Changing the filter immediately reduces the oil comsumption, once again.

My "system" for the '85/'86 engines uses a custom oil separator that I buy and modify substancially, to eliminate the Provent and any "service" requirement. This oil separator is expensive to buy initially and even more expensive, once I've spent several hours modifying it. I'm working on a custom version, made from scratch, that I will test on the '87 and later application.







​​​​


Old 10-26-2018, 03:49 PM
  #12  
The Forgotten On
Rennlist Member
 
The Forgotten On's Avatar
 
Join Date: May 2012
Location: Thousand Oaks California
Posts: 4,926
Received 296 Likes on 244 Posts
Default

Geez, the oil separator you're using cost nearly 3X as much as a Provent 200. But if it works, it works.
Old 10-26-2018, 04:01 PM
  #13  
FredR
Rennlist Member
 
FredR's Avatar
 
Join Date: Jun 2005
Location: Oman
Posts: 9,700
Received 664 Likes on 541 Posts
Default

Originally Posted by GregBBRD
Fred:

I really don't' pay too much attention to claims by people or manufacturers, but rely on my own testing and observations.

There is little doubt, in my mind, that the Provent 200 is marginal for the 928 application, especially in engines that have high blowby and the resulting severe oil consumption. I've found that these engines will initially have significantly reduced oil consumption (with my plumbing and pieces), but as soon as the filter becomes completely covered with oil, the oil consumption will increase again. Changing the filter immediately reduces the oil comsumption, once again.

My "system" for the '85/'86 engines uses a custom oil separator that I buy and modify substancially, to eliminate the Provent and any "service" requirement. This oil separator is expensive to buy initially and even more expensive, once I've spent several hours modifying it. I'm working on a custom version, made from scratch, that I will test on the '87 and later application.

​​​​
Greg,

Many thanks for that- tends to confirm my suspicion that the Pro Vent is not all that it seems to be [or what we wishfully hope it could be]. I think I will try removing the Pro Vent altogether and just rely on the baffle to see if that makes a difference. When I tried my current iteration of the breather system with mods suggested by Tuomo, the oil consumption dropped noticeably initially but slowly it seems to gone up again- never figured the screen itself would be that restrictive but maybe that is the problem? Given it is not taking out out any significant amount of oil maybe I can simply pull the separator element out altogether to allow a free flow of the gas and see what that does, that or simply remove the thing altogether as I have been thinking about doing.
Old 10-26-2018, 04:37 PM
  #14  
GregBBRD
Rennlist
Basic Site Sponsor
 
GregBBRD's Avatar
 
Join Date: Feb 2005
Location: Anaheim
Posts: 15,219
Received 2,451 Likes on 1,459 Posts
Default

Originally Posted by The Forgotten On
Geez, the oil separator you're using cost nearly 3X as much as a Provent 200. But if it works, it works.
Absolutely correct. And then I modify it...for several hours on both my mill and lathe. Imagine what it costs when it finally hangs on an engine and does its job!

The cost of an item is not something I pay attention to, when I'm making prototypes and doing development work. I've got shelves full of pieces I've tried, which don't work like I want them to. If I find something which works better, then I look at the practicality of using it.
__________________
greg brown




714 879 9072
GregBBRD@aol.com

Semi-retired, as of Feb 1, 2023.
The days of free technical advice are over.
Free consultations will no longer be available.
Will still be in the shop, isolated and exclusively working on project cars, developmental work and products, engines and transmissions.
Have fun with your 928's people!





Old 10-26-2018, 04:45 PM
  #15  
GregBBRD
Rennlist
Basic Site Sponsor
 
GregBBRD's Avatar
 
Join Date: Feb 2005
Location: Anaheim
Posts: 15,219
Received 2,451 Likes on 1,459 Posts
Default

Originally Posted by FredR
Greg,

Many thanks for that- tends to confirm my suspicion that the Pro Vent is not all that it seems to be [or what we wishfully hope it could be]. I think I will try removing the Pro Vent altogether and just rely on the baffle to see if that makes a difference. When I tried my current iteration of the breather system with mods suggested by Tuomo, the oil consumption dropped noticeably initially but slowly it seems to gone up again- never figured the screen itself would be that restrictive but maybe that is the problem? Given it is not taking out out any significant amount of oil maybe I can simply pull the separator element out altogether to allow a free flow of the gas and see what that does, that or simply remove the thing altogether as I have been thinking about doing.
There's apparently a mesh screen available for the Provent. I have not tried this...


Quick Reply: ProVent filter cleaning - how?



All times are GMT -3. The time now is 04:59 AM.