Ideas for PCV system variations

[SILVER2000SVT]

With all the discussions concerning the "oil in the intercooler" and oil separators lately and talking with TEX last night prompted me to make an attempt at putting some diagrams together with pros and cons of each and how they compare to the stock setup. I left out totally removing the pcv system. My goal was to tweak the system as it comes from the factory and address some of the issues that it seems to cause.

I'm hoping for an educated discussion on the subject, and we may just come across something that works better and hasn't been thought of yet.

http://www.svtgalleries.net/gallery/data/500/DIAGRAM_A1.jpg
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(http://www.svtgalleries.net/gallery/showphoto.php?photo=15001&size=big&cat=500&page=1)
http://www.svtgalleries.net/gallery/data/500/DIAGRAM_C1.jpg

http://www.svtgalleries.net/gallery/data/500/DIAGRAM_D1.jpg

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[Silver_2000]

use the copy to clipboard function of the gallery to show the pcitures here

http://www.svtgalleries.net/gallery/data/500/DIAGRAM_A1.jpg

[SILVER2000SVT]

use the copy to clipboard function of the gallery to show the pcitures here



Thanks Doug,
I finally figured it out, I was trying to make hard....

[Mark #2]

This is my solution, I have had others and I think that this is the best compromise:

Put a water/oil compressor type on the upper intake tube and put a pop-up sprinkler head filter in the drivers side valve cover. Both of these provide for a condensation surface for the oil vapors. This works IMHO.

I clean the compressor type at every oil change.
Mark

[SILVER2000SVT]

This is my solution, I have had others and I think that this is the best compromise:

Put a water/oil compressor type on the upper intake tube and put a pop-up sprinkler head filter in the drivers side valve cover. Both of these provide for a condensation surface for the oil vapors. This works IMHO.

I clean the compressor type at every oil change.
Mark

Are you talking about the cone shaped screen from a sprinkler head?

That's probably a pretty good compromise. The only time oil should come out into the intake boot is under boost and WOT. That SHOULD be a relatively small part of the time that the truck is running. So if you have the condensation surface on the drivers side to take the temporary vapor from positive crankcase pressure that would reduce the oil getting into the intake boot.

[Tex Arcana]

I've got to think about these.. but they're well thought-out. HOwever, in the last scenario, I can see a problem with crankcase pressure building due to ring blowby, especially under boost.

I think crankcase venting is hghly important, if only to scavenge blowby gasses from the crankcase; the partial vacuum/ring seating is just a plus.

We need to find out if that "metered orifice" in the lower intake is actually a check-valve of some sort, or is just an opening into the intake.

Hmmmmm....

EDIT: it'd be nice to install a set of flow meters on the PCV system, to see how it flows under different conditions.

[Mark #2]

Are you talking about the cone shaped screen from a sprinkler head?

That's probably a pretty good compromise. The only time oil should come out into the intake boot is under boost and WOT. That SHOULD be a relatively small part of the time that the truck is running. So if you have the condensation surface on the drivers side to take the temporary vapor from positive crankcase pressure that would reduce the oil getting into the intake boot.

Yes, the system must flow in both directions on both sides. It does work I have had is this way for two years with KB at 15psi no oil in the intake.
Mark

[SILVER2000SVT]

I've got to think about these.. but they're well thought-out. HOwever, in the last scenario, I can see a problem with crankcase pressure building due to ring blowby, especially under boost.

I think crankcase venting is hghly important, if only to scavent blowby gasses from the crankcase; the partial vacuum/ring seating is just a plus.

We need to find out if that "metered orifice" in the lower intake is actually a check-valve of some sort, or is just an opening into the intake.

Hmmmmm.... :bows

None of the options provide for vacuum under boost at WOT, I think the only way that can happen is with a separate vacuum pump.

So far my personal favorite is diagram D that will actually circulate air through the crankcase better than the stock set up and even help maintain a vacuum on the crankcase during boost on part throttle runs.

If you look the last diagram E, is pretty drastic. I was thinking outside the box on that one. It is cool because the pcv will circulate better than any of the other systems under vacuum but not at all under any boost regardless of throttle position. There's also no chance of getting oil on the intercooler. If you see, there is a check valve to atmosphere, if by some chance the blowby gases build to a positive pressure on Diagram E it will vent them out there.

[Tex Arcana]

None of the options provide for vacuum under boost at WOT, I think the only way that can happen is with a separate vacuum pump.

So far my personal favorite is diagram D that will actually circulate air through the crankcase better than the stock set up and even help maintain a vacuum on the crankcase during boost on part throttle runs.

If you look the last diagram E, is pretty drastic. I was thinking outside the box on that one. It is cool because the pcv will circulate better than any of the other systems under vacuum but not at all under any boost regardless of throttle position. There's also no chance of getting oil on the intercooler. If you see, there is a check valve to atmosphere, if by some chance the blowby gases build to a positive pressure on Diagram E it will vent them out there.


I'm thinking D is the best compromise as well; all of these are based on how exactly that metered orifice actually acts in various conditions, tho.

Mark's idea is very similar to mine with the steel wool, but that can work as well.

Hang on a second.. will the orifice in the upper plenum pull vacuum when it's under boost and WOT??

[SILVER2000SVT]

Hang on a second.. will the orifice in the upper plenum pull vacuum when it's under boost and WOT??

The upper plenum connection should just be wide open, there shouldn't be much of a restriction like an orifice or anything. It is before the supercharger, and therefore is under vacuum all the time, right?

Because the flow is based on the pressure difference between two points (the upper plenum and the intake boot), even though there's lots of air flowing through the intake during WOT there is little difference in the pressure between the points and doesn't induce as much flow through the crankcase. This is where D is good because the small amount of air flow coming out of the lower intake oriface is now a more significant presense than air flow created from the upper plenum to intake boot differential and is being forced through the crankcase and eventually back into the upper plenum

[Tex Arcana]

The upper plenum connection should just be wide open, there shouldn't be much of a restriction like an orifice or anything. It is before the supercharger, and therefore is under vacuum all the time.

Because the flow is based on the pressure difference between two points (the upper plenum and the intake boot), even though there's lots of air flowing through the intake during WOT there is little difference in the pressure between the points and doesn't induce as much flow through the crankcase. This is where D is good because the small amount of air flow coming out of the lower intake oriface is now a more significant presense than air flow created from the upper plenum to intake boot differential and is being forced through the crankcase and eventually back into the upper plenum


Couple that with the vacuum present in the upper plenum, you get not only good positive flow, but possible vacuum in the crankcase, which would enable better ring sealing and less blowby... hmmm...

[Beaudee]

I would like to attack the problem where it starts in the valve cover.I havent had my covers off yet, but i would like to see the backside if anyone has a pick.I think a better baffle would be nice.I like stainless and aluminum.I was certified aircraft welder @ Associated Air Center for years and built some cool baffles for aircraft.Just wondering how much room in the cover.

[Mark #2]

I would like to attack the problem where it starts in the valve cover.I havent had my covers off yet, but i would like to see the backside if anyone has a pick.I think a better baffle would be nice.

Yup, that would do it, I guess you could fiberglass some baffles into the covers. Not sure how much room is above the cams though. I will take a look tonight.

Mark

[SILVER2000SVT]

I was also thinking about "D". This could be simplified and have the check valve going to the lower intake removed. I did it that way to maximize the air flow going through the crankcase during non-boost, but after thinking about it, the same air flow would go through the crankcase without it, there would just be the additional airflow going into the intake boot line to feed the vacuum from both the lower intake vacuum and the upper plenum vacuum.


I would like to attack the problem where it starts in the valve cover.I havent had my covers off yet, but i would like to see the backside if anyone has a pick.I think a better baffle would be nice.

You definitely have a point. If you can knock out a good bit of the oil getting into the PCV line it would take care of a lot of the problem.

[Mark #2]

My final post on this

......no but I did stay in a Holiday Inn express last night.

[Beaudee]

I am just gone to bare and grin @ the problem,and just keep dumping the oil sep..I would like to see ford fix the problem on a recall. :rll: The sep. i installed on the drivers side has never collected any oil.I am just stock boost though.I did remove the filter in the bowl on the drivers side due to the concern of backpressure,it wasnt a LFP like i installed on the pass. side, it was a steada.Even since i removed the filter and reinstalled the bowl not a drop of oil,or any color in the bowl,clean as a whistle even with my lead foot.The bowl is nice to have to keep an eye on things.

[SILVER2000SVT]

I am just gone to bare and grin @ the problem,and just keep dumping the oil sep..I would like to see ford fix the problem on a recall. :rll: The sep. i installed on the drivers side has never collected any oil.I am just stock boost though.I did remove the filter in the bowl on the drivers side due to the concern of backpressure,it wasnt a LFP like i installed on the pass. side, it was a steada.

If the stock system is working properly you should never get oil in the drivers side. That only occurs if the upper plenum can not pull enough air to compensate for the pressurized air coming from the lower intake orifice during boost and the blow by gases. Like I mentioned on diagram B anyone running a separator is more likely to see this occur because of the extra restriction, but if you let the seperator clog up it's pretty much a guarantee that the crankcase pressure will go back to the drivers side. So it sounds like yours it working correctly right now.

[Beaudee]

One thing i would like to add is i was using mobil 1 0-20 when i bought the truck and since last oil change of mobil 1 5w-20w the oil sep on the pass. side doesn't fill as often even though it still collects. :tu: Viscosity is a factor along with boost and engine wear, driving habits.Way to go mobil 1 on the 5-20.

[Tex Arcana]

Mark, Beaudee, I think you'll find that there's a small "baffle box" beneath the holes in each valve cover, I saw a pic somewhere (searching as we speak), which is *almost* 3-sided (open on one side, don't know which way is faces).

As I said in PoorSVTMan's thread, I did this same trick with the steel wool with my '79 Supra, which had a similar problem, and it worked like a champ. Plus, you don't run the risk of temperature or chemicals attacking the metal like you do with a plastic filter.

Mark, if you're gonna pull your covers, take pics, pls.

[Tex Arcana]

I am just gone to bare and grin @ the problem,and just keep dumping the oil sep..I would like to see ford fix the problem on a recall. :rll: The sep. i installed on the drivers side has never collected any oil.I am just stock boost though.I did remove the filter in the bowl on the drivers side due to the concern of backpressure,it wasnt a LFP like i installed on the pass. side, it was a steada.Even since i removed the filter and reinstalled the bowl not a drop of oil,or any color in the bowl,clean as a whistle even with my lead foot.The bowl is nice to have to keep an eye on things.

Which direction is that separator flowing?? If your arrow is pointing from the boot to the valve cover, it won't collect a thing, but it should get dirty from the inside.

Wait a sec: you removed your filter?? Why?? If it was getting dirty on the inside, and not collecting oil, it was flowing the wrong direction. Also, there should've been a ring at the top, looking like a gear, that forces the air to flow in a cyclonic pattern, to help with separation.

[Beaudee]

The arrow is flowing from the valve cover to the air intake.Even with the filter installed it never got dirty or collected oil.The filter was white and looked like made for water.It had a number 5 on it.I thought it might have too much back pressure. even with it removed it would still catch something, but the sep. is not really needed at all as far as i can tell.

[Tex Arcana]

The arrow is flowing from the valve cover to the air intake.Even with the filter installed it never got dirty or collected oil.The filter was white and looked like made for water.It had a number 5 on it.I thought it might have too much back pressure. even with it removed it would still catch something, but the sep. is not really needed at all as far as i can tell.

THe filter is similar to the one mentioned by Mark, and is there to help coalesce the misted oil that didn't collect on the sides of the bowl, and trap it. Were you having problems with oil in your boot before?

[dboat]

Tex,
saw this over on F150online.. thought it was a little different..

Dana

[Tex Arcana]

Tex,
saw this over on F150online.. thought it was a little different..

Dana

Definitely different.. thanks

[Mark #2]

Both valve covers are the same.

[dboat]

Both valve covers are the same.

Do you run synthetic oil?

[Mark #2]

Yes, why?

[Tex Arcana]

Both valve covers are the same.
Pics would be nice. :D

EDIT: Dialup and Linux tend to mess me up. :(

[Mark #2]

Pics would be nice. :D
Look about 3 posts up...

[Tex Arcana]

Look about 3 posts up
yeah, sorry, I"m on dialup, and just installed Manrdrake 10.1, and am playing around with it, so I missed the thumbnail placeholders 'til after i posted my reply.

If I'm seeing the pics properly, it's a fairly small three-sided box, with a small opneingn on the fourth side. And it's not terrifically large, either, so maybe stuffing steel woll in there isn't gonna be so hard. Hmmmmm...

[dboat]

Yes, why?

They look clean, but I was thinking that maybe, JUST MAYBE, there wouldnt be any black at all in there..

Dana

[Mark #2]

They look clean, but I was thinking that maybe, JUST MAYBE, there wouldnt be any black at all in there..

Dana

Dana, the covers are black plastic, so they will look black, these are brand new covers, no miles.

[dboat]

Dana, the covers are black plastic, so they will look black, these are brand new covers, no miles.

:o ok, stupid me.. thanks
Dana