Smoke after breathers installed normal?

o2sys

Senior Member
Joined
Jun 26, 2011
Posts
4,367
Reaction score
21
Location
NY/NJ
So what causes the driver side pcv in the cam cover to open?

The vacuum from the intake manifold?

Under what conditions? WOT only?
 

46addict

13726548
Joined
Aug 25, 2016
Posts
1,832
Reaction score
56
Location
Lawrenceville, GA
The engine creates vacuum at closed/part throttle conditions and that is when the PCV stays open. At zero vacuum the valve will close.
All vacuum lines lead to the intake manifold.
 

07 Boss

Senior Member
Joined
Jan 25, 2009
Posts
4,302
Reaction score
1,418
Location
Sin City
Unless you intend on running the car mostly for racing or track use, I wouldn't recommend using breathers anyhow.. For daily driver and street use, I really don't think there's any benefit in disabling the factory PCV system in favor of venting the crankcase to atmosphere with valve cover breathers..

Even if the PCV valve is removed by providing 3 paths for venting the crankcase, there still needs to be enough crankcase pressure for pushing the bad air out to begin with, otherwise the majority of crankcase vapors end up remaining in the crankcase causing contamination and eventually shortening the life of your rings and seals..

This is true. You will not get the same effect of clearing out the the vapors. A lot more stuff gets dissolved back into the oil. I change my oil more frequently because of that fact.

I actually ran breathers for awhile to find out just how effective they were over the factory PCV system and although they prevented crankcase vapors from entering the intake manifold and back into the crankcase itself, I found out through personal experience there was nothing coming out of the driver side cam cover because of the PCV valve not being removed first which only allowed for just one path on the passenger side cam cover for venting the crankcase..

So rather than going through the hassle of uninstalling the driver's side cam cover and then by having to cut open the PCV housing tube just in order to remove the valve and hope that nothing goes wrong.. That was just a risk in which I was not willing to take, therefore being that my car is mostly used for street use and isn't taken to the track anyhow, I decided that it was best to just leave the factory PCV system in place and run UPR's latest 4 chamber design catch can/oil separator instead.. So far after 4 months, the UPR separator seems to be doing it's job quite well..


Removing the PCV valve is a simple operation and it is pretty hard to eff it up. I just cut the little baffle plate and bent it back. Cut the line with the pcv valve in it and bent the plate back up. It's not rocket science.

The PCV system is a smog thing. Back in the day all engines had breathers. I've been using breathers for 30+ years on all of my performance motors without any ill effects.



As for running a breather in place of the factory oil cap goes, I also wouldn't recommend replacing the oil cap unless the breather has a one way check valve for preventing un-metered air from entering the crankcase..

What difference does it make? The breather on the oil cap is going to do the same as the other breathers. I mean they all go to the same place. Running a check valve on one is not going to prevent air from entering from the other two breathers. That's kinda silly. Unless maybe you mean running the oil cap breather with a stock pcv system. That would be a no-no. I'm saying if you go breathers you should go with all three instead of the one or two.

Anyway just my $.02..


There are pros and cons to swapping to breathers and that debate is wore out. It comes down to how you weigh those pros and cons for whatever purpose your car has. It's not for everybody but if you're going to do it there is a best way to do it.
 

o2sys

Senior Member
Joined
Jun 26, 2011
Posts
4,367
Reaction score
21
Location
NY/NJ
So if the driver side pcv opens during idle using the vacuum from the intake manifold and if I put a breather tank inline it would cause a vacuum leak?
 

06 T-RED S/C GT

Senior Member
Joined
Jan 8, 2016
Posts
2,270
Reaction score
370
Location
Carnegie, PA
There are pros and cons to swapping to breathers and that debate is wore out. It comes down to how you weigh those pros and cons for whatever purpose your car has. It's not for everybody but if you're going to do it there is a best way to do it.

Yes ! Your right, I should had said that only if the PCV system isn't fully disabled that running a breather regardless of replacing the oil cap or on the cam covers will then cause an un-metered air condition as in a vacuum leak..

Therefore I stand corrected.. Either you completely disable the PCV system altogether before switching over to breathers or leave the PCV fully in tact and run a catch can/oil separator..

So if the driver side pcv opens during idle using the vacuum from the intake manifold and if I put a breather tank inline it would cause a vacuum leak?

Yes ! it most certainly will cause a vacuum leak.. You have to fully disable the factory PCV system by capping off your vacuum port at the intake manifold and also at the intake air tube on your passenger side..

As Bruce and 07 Boss also mentioned, before switching over to breathers also make certain that you remove the PCV valve on the driver's side cam cover first, otherwise you'll end up limiting the crankcase to vent from only the passenger side cam cover..

If you don't remove the PCV valve before installing breathers, the PCV valve will not open, as the valve relies on vacuum from the intake manifold to open it.. Therefore if you disable the factory PCV system by just capping it off, but end up leaving the PCV valve in place, the valve will no longer be able to open once you cap off the vacuum port coming from the intake manifold which means your crankcase from the driver's side port will no longer be able to vent as a direct result..
 

o2sys

Senior Member
Joined
Jun 26, 2011
Posts
4,367
Reaction score
21
Location
NY/NJ
Hmm so that's probably why all the vapors are coming out of the passenger side only.

I'm going to reroute it like this :

Pass. Side vented with filter only.

Driver side non-vented with catch can so the intake manifold can open the pcv in the cover.
 

eighty6gt

Senior Member
Joined
May 9, 2011
Posts
4,306
Reaction score
417
Sounds good how are you accounting for the unmetered air entering the engine?

http://vmpperformance.com/v/IMAGESP...upgrade instructions & parts list 3-15 JS.pdf

"The driver’s side PCV hose should be deleted to prevent oil ingestion into the supercharger and potential vacuum leaks.
Use the supplied ½” cap on the valve cover. The engine is still vented through the other valve cover. "

You can do anything!
 

o2sys

Senior Member
Joined
Jun 26, 2011
Posts
4,367
Reaction score
21
Location
NY/NJ
There won't be any unmetered air injested with my new routing.

Where would the unmetered air come from?
 

07 Boss

Senior Member
Joined
Jan 25, 2009
Posts
4,302
Reaction score
1,418
Location
Sin City
Hmm so that's probably why all the vapors are coming out of the passenger side only.

I'm going to reroute it like this :

Pass. Side vented with filter only.

Driver side non-vented with catch can so the intake manifold can open the pcv in the cover.

There won't be any unmetered air injested with my new routing.

Where would the unmetered air come from?


No, don't do it that way. Like it was stated before, once you open up the system you have to open it up all the way. If you put a breather on the passenger side and then have your intake hooked to the drivers side you will get unmetered air into your manifold. Every time there is manifold vacuum the valve will open and suck air out of the motor which enters through the breather on the passenger side (unmetered). If you are going to leave the intake manifold hooked up, you must draw the air from the intake tube after the MAF (metered).



Here is a stock system. You can see here that any air entering the manifold is metered by the MAF. Once you put a breather on that side there is nothing metering the air taken into the motor which travels back into your intake manifold.
 

eighty6gt

Senior Member
Joined
May 9, 2011
Posts
4,306
Reaction score
417
I would take both valve covers off and gut out the pcv stuff, and then put a vertical tube down underneath the car with a slash cut facing backwards, on both sides, this way as you drive the venturi effect will make a draw on this "roading tube," and help get the crankcase gases/oil/sludge out onto the road behind you.

https://books.google.ca/books?id=3i...epage&q=model t crankcase ventilation&f=false

Holy freaking crap look at what electric tools cost in 1963!!!
 
Last edited:

46addict

13726548
Joined
Aug 25, 2016
Posts
1,832
Reaction score
56
Location
Lawrenceville, GA
I'm not sure what that venturi effect translates to in in/Hg of vacuum, but the way I see it, there are two ways to do this.

1) Install a breather in all three openings and run with the risk of a closed PCV, forcing all gases to escape through the passenger side & oil filler neck. And as stated before the oil filler breather will need a one way check valve.
2) Run an oil separator on both sides.

The third option is to leave the stock system alone and deal with the oil residue in the intake tract.
 

eighty6gt

Senior Member
Joined
May 9, 2011
Posts
4,306
Reaction score
417
Or you could install a provent on the large driver's side line and route the outlet to manifold vacuum, and leave the passenger feed hooked to metered air.
 

o2sys

Senior Member
Joined
Jun 26, 2011
Posts
4,367
Reaction score
21
Location
NY/NJ
Also right now I'm on a blow thru setup I can't really go back to "stock" pcv because even if I connect the passenger side to the cold air intake it would still be premaf and considered unmetered.
 

06 T-RED S/C GT

Senior Member
Joined
Jan 8, 2016
Posts
2,270
Reaction score
370
Location
Carnegie, PA
Hmm so that's probably why all the vapors are coming out of the passenger side only.

I'm going to reroute it like this :

Pass. Side vented with filter only.

Driver side non-vented with catch can so the intake manifold can open the pcv in the cover.

As mentioned, you have to completely disable the factory PCV system altogether by first removing the PCV valve from the driver's side cam cover and then capping off both the vacuum port from the intake manifold and air intake tube attached to the throttle body..

There won't be any unmetered air injested with my new routing.

Where would the unmetered air come from?

If putting a catch can on the PCV side and putting a breather on the passenger side, the PCV system remains fully active and will therefore result in a vacuum leak..

The bottom line is, you cannot run an open breather setup with a closed PCV system still intact.. With the PCV fully active, running an open breather will cause a vacuum leak even if you cap off the air intake tube, as this will now result in un-metered air to pass through the open breather and then into the intake manifold.. The un-metered air would come from leaving the PCV system fully intact while running an open breather..

So once again, either you leave the PCV system fully intact with or without a catch can or disable the system altogether and run just breathers, but you can't run both at the same time..
 
Last edited:

06 T-RED S/C GT

Senior Member
Joined
Jan 8, 2016
Posts
2,270
Reaction score
370
Location
Carnegie, PA
Or you could install a provent on the large driver's side line and route the outlet to manifold vacuum, and leave the passenger feed hooked to metered air.

Heck, might as well just run a catch can and leave the factory PCV fully active rather than install what you recommend on the driver's side and then have to re-route the outlet to manifold vacuum :shrug:
 

dmfracer

Junior Member
Joined
Feb 28, 2014
Posts
44
Reaction score
0
Location
Kingwood, Tx (Houston)
You should try running a PCV valve designed for a boosted car - GT500, Terminator, 2nd gen Lightning. And then run an oil catch can in the return line to the intake.
 

o2sys

Senior Member
Joined
Jun 26, 2011
Posts
4,367
Reaction score
21
Location
NY/NJ
I don't feel like tapping into my Paxton throttle body elbow to run the passenger side pcv.

I'm just going to cut out the pcv inside the driver side cam cover (got an extra one) and run it fully open on both sides.
 

07 Boss

Senior Member
Joined
Jan 25, 2009
Posts
4,302
Reaction score
1,418
Location
Sin City
1) Install a breather in all three openings and run with the risk of a closed PCV, forcing all gases to escape through the passenger side & oil filler neck. And as stated before the oil filler breather will need a one way check valve.

If you are running breathers you do not need a check valve on the oil cap breather. The system is open at two points, a third is not going to make a difference. All the air in the breather set up is unmetered but it's not going into your cylinders so it doesn't make a difference. If you run a check valve with the two open breathers you defeat the purpose of the third breather. There will hardly ever be enough pressure to open the valve and then you are left with just the two breathers.

If you run the stock closed system and want to run an oil cap breather with a check valve, that is OK. Some boosted applications will prefer this method because of the pressure in the manifold will prevent the pcv valve from opening and you will have a pressure release in a breather with a check valve when needed.

I have run the 3 open breathers from the beginning of time with my car, both boosted and N/A.
 
Last edited:

BruceH

BBB Big Bore Boss 322
Joined
Sep 13, 2009
Posts
13,810
Reaction score
21
Location
Pacific Northwest
This topic has been beat to death in the past. There is a whole lot of good info to be obtained with a search.
 

06 T-RED S/C GT

Senior Member
Joined
Jan 8, 2016
Posts
2,270
Reaction score
370
Location
Carnegie, PA
I'm not sure what that venturi effect translates to in in/Hg of vacuum, but the way I see it, there are two ways to do this.

1) Install a breather in all three openings and run with the risk of a closed PCV, forcing all gases to escape through the passenger side & oil filler neck. And as stated before the oil filler breather will need a one way check valve.
2) Run an oil separator on both sides.

The third option is to leave the stock system alone and deal with the oil residue in the intake tract.

As long as all vacuum ports are capped off, both manifold vacuum and air intake tube off the throttle body, the PCV system is completely disabled so it won't no longer matter if the oil filler breather has a one way check valve or not..

Once the PCV system has been disabled, un-metered air is no longer a factor, however I still wouldn't recommend installing breathers until removing the PCV valve first, as you want as many ports open as possible for venting crankcase pressure when running an open breather setup rather than just through the passenger side and oil filler neck..


You should try running a PCV valve designed for a boosted car - GT500, Terminator, 2nd gen Lightning. And then run an oil catch can in the return line to the intake.

How would this be accomplished ? The PCV valve is integrated inside the driver's side cam cover on all 3v 4.6 motors.. They're not like traditional PCV valves that are replaceable as are the older 4.6 4v Terminator and 2nd gen Lightning.. In order to replace the PCV valve, the 4.6 3 valves require replacing the entire cam cover..

I don't feel like tapping into my Paxton throttle body elbow to run the passenger side pcv.

I'm just going to cut out the pcv inside the driver side cam cover (got an extra one) and run it fully open on both sides.

As long as you cap off both the vacuum/manifold side and air intake elbow after the throttle body, you'll have all 3 ports in which the crankcase can vent from once you remove the PCV valve..
 

Support us!

Support Us - Become A Supporting Member Today!

Click Here For Details

Back
Top