Putting a Stop to Oil Consumption through the PCV Valve

Discussion in 'Fox 5.0 Mustang Tech' started by vristang, May 19, 2006.

  1. I think it is great that so many of you guys are contributing, with good ideas.:nice:

    It also shows how much of a problem this is for so many of us. :notnice:

  2. if you had a pcv and an air inlet on the same valvecover, then air would only cycle through that particular side of the engine. I figure it'd be best to maintain the stock pcv along with another pcv on the driver valvecover, with the air inlet on the passenger side valvecover. That way, the vapors would have to travel across the crankcase to get pulled into the manifold.

    what intakes, rockers, and heads do you guys have?
  3. Good point.

    Tmoss ported stock intake, Ford 1.6 Roller Rockers, ported stock heads.
  4. Stock Covers with baffle removed/ground off, Trickflow Street Heat intake, Trickflow 1.7 Roller Rockers, Ported Windsor Jr's with 7/16th studs, and Crower 15511 cam.
  5. I found this on another post...........Seems to answer most of our questions.

    Contemporary PCV systems are part of the emissions system of the car -- as such the EPA had more to do with their design than anyone else.

    Any engine builds crankcase pressure when it runs. Some blow by makes it past the rings, and each time a piston moves down in the bore it compresses the air in the crankcase underneath it. So there's lots of exhaust/unburned-hydrocarbons/vaporized-misted hot oil blowing around at a pretty good velocity inside the crankcase when the engine is running. That crankcase pressure has to be relieved or it will blow out seals and gaskets. Many a leaking rear main seal has nothing to do with a bad seal, and everything to do with a malfunctioning pcv system that is allowing crankcase pressure to build.

    Back in the day, most engines just had a big pipe attached to the crankcase that hung down under the car. Wasn't uncommon to see them blowing 'smoke' out of it as they'd chug down the road.

    The EPA decided that they didn't want that mess fouling the air -- and that was the beginning of the crankcase ventilation systems of today. Early systems were nothing more than a connection from the valve cover (i.e. - crankcase) to the air filter - with some filtering media to knock oil out of the air stream. This fed the nastiness being put out by the crankcase back into the engine to be combusted.

    The next versions decided they could 'suck' the stuff out of the crankcase by letting manifold vaccum pull on it. The PCV system was born -- POSITIVE crankcase ventilation -- meaning, we're not gonna let it come out under it's own power, we're gonna suck it out of the crankcase. So pcv valves (a simple check valve) were installed in the valve cover, and a hose to the base of the carb provided a vacuum source. The pcv/check valve was necessary so that no air/fuel mixture from the carb could find it's way into the crankcase through the hose/valve cover. Crankcase explosions are nasty. So due to the pcv/check valve air could only move from the cover to the manifold, not the other way.

    As sequential fuel injection came along on the 5.0's the new spot for accessing the crankcase was the back of the lower intake. A rubber grommet holds the pcv valve which connects to the upper intake manifold via hose. Below the grommet is a wire-mesh screen that acts as an oil trap -- designed to knock as much oil out of the crankcase flow as it can. The last part of the contemporary pcv system on the efi HO 5.0's is the little hose that runs from the throttle body to the valve cover oil filler neck nipple. When manifold vacuum sucks on the crankcase, eventually it's going to pull air INTO the crankcase from the outside. That air is going into the intake as part of the combustion air -- so in a mass air car it really needs to be metered air. And, if you don't allow a source for it -- we'll call it 'make up air' -- eventually you'll pull a vacuum on the crankcase; not what the designers wanted. That little hose between throttle body and valve cover provides a source of metered make-up air for the system. When vacuum is present in the intake, metered air (it's already passed through the maf) moves from the throttle body into the crankcase (via valve cover) to make up for the air being sucked from the crankcase via the pcv/manifold connection. At wide open throttle when there is no manifold vacuum, the same hose serves to help vent the crankcase if the pcv/valve/hose can't keep up with the volume the crankcase is producing. So the little hose between the throttle body and the valve cover is bi-directional.

    When the oil trap/screen beneath the pcv valve becomes clogged, all the crankcase ventilation has to occur through that little throttle body hose. It's not uncommon for a bunch of oil to collect up in the throttle body/air inlet piping. That's a symptom of a clogged oil trap or clogged pcv valve. It's exacerbated when someone removes the oil baffle in the cover to clear 1.7 rockers with the stock covers...

    Got it?
  6. My contribution and permanent cures :D .

    Like all I got pi*ssed off with this problem not long after installing a 5.0 in my Oz 4Runner in 1993 and gave thought on how to cure it permanently or at least so I didn't have to constantly check oil levels etc on long runs.

    I assume most know that when you fire up, the sump and valley etc are basically smothered in a fine oil mist from the crank flogging the oil etc, ie you can't see through it. So the valley area is covered in a fine oil mist which gets sucked up the pcv etc.

    I figured the only way to eliminate most of this was via an extra baffle system.

    This is the system I fitted to my GT40 stock manifold. The pcv entry section at the rear of the manifold is completely blocked off by a piece of this steel plate shaped to fit and its also welded to the larger plate. There are 3 small boss extensions in the manifold that can be drilled and tapped for bolts.

    I then welded a piece of 1/2" tube to the flat plate section and also into the now sealed pcv entry. The tube ends about where the bolt is at the front of the engine.

    Cured the excess oil problem for good :D


    I now have a 8 trumpet manifold setup that I fabbed up and I had to locate the pcv in the center of the lower manifold section. Upon testing this new setup I later found the upper airbox was literally covered in oil, so again I decided to use my old system but go a step further.

    Using the two bolts that hold the lifter clamp down in the valley I mounted a piece of alloy as per this pic.


    I then fabbed a full baffle system. The outside edges are cut to follow the head contours and silasticed to the head just under the intake ports. This also stops oil from contaminating the intake gaskets :D

    The air enters at the front via the hole that is just visable and also via the small slot section at the rear. Also the underside of the manifold itself has a sneaky cover over the pcv entrance that has a series of small holes drilled on the sides (not underneath). This cover also has additional wire separators inside. I will take a pic later as I do plan to remove the lower soon for other reasons.

    My new upper maifold is now dry as a bone and it sucks hard when idling even with the E303 :D

  7. Nice work JD, you've got too much time on your hands :)

    If you try this, be REAL CAREFUL about the length of those spider hold down bolts - if they are too long you'll have a problem with the cam..........
  8. My goodness JD, nice work for a cure, But I sure as hell don't have the time to mess around taking crap back apart and fabbing up plates. That is SWEET. You were determined to stop this dead in it's tracks, NICE WORK!
  9. Not sure if the valve covers will clear with a 3/8" spacer to be honest. I know with the Conra intake If I didn't have the 1" there was no way it would fit with the 3/8." I would not do 3 PCV valves. You need to keep the TB to valve cover tube connected on the pass side.

  10. Yeah Jason I will let you all know how it works out with the PCV on the driver side valve cover. My car, unfortuneatly, right now is at the body shop for about a week getting a new 2.5" Storman Norman hood!!! But I will let Ya'll now as soon as I get it back.
  11. right on guys. it's like we have a little PCV braintrust going on... where's FDR?
  12. Well guys got my car back from the body shop after the Storman Norman Hood install, Looks KILLER! And finally for the GREAT NEWS. I relocated my PCV valve to my driver side valve cover and ran the hose from the valve under my intake through the oil seperator (in-line) and to the intake. Stock location PCV valve in the lower intake is now plugged. Still have the TB tube for fresh air connected to my pass side valve cover.

    NO MORE OIL!!!!!

    Thank GOD this worked for me!!! :nice:
  13. I am glad that this has reduced the oil in your intake. :nice:

    I am curious how well this allows the crankcase gasses to vent though.
    My concern is that this setup will not force fresh air to flow through the crankcase, which will lead to increased oil degradation/contamination.

    I am not sure how to check for crankcase air flow though. I think the only way to find if this is an issue or not would be to have a before and after oil analysis done.

    More random thoughts from...
  14. Jason,

    There is nothing to be concerned about. The fresh air is forced to flow through the crankcase by means of the TB tube connected to the Pass side valve cover like the stock set-up. The only thing I did was re-locate the PCV to the driver side valve cover. This allows for the crankcase to be vented same as the stock location at the rear just that now it is vented at the front of the crankcase rather than at the back of the crankcase. It's the same thing and even more effective than a breather as the intake vacuum that is created pulls the gasses out like the stock set-up.
  15. :doh:
    I thought you put the new pcv on the passenger valve cover.
    I'll learn to read one of these days :nonono:

    Sounds like a good setup :nice:

  16. Thanks, I figured you may have missed something :D
  17. My 2 cents on oil elimination(my attempt in photo!)

    You seen it here first :SNSign: !![​IMG] Patent Pending , DIY all you like tho :flag:
    Hope some of you find this interesting :nice:
  18. Hink -
    What on earth is that :shrug:

    What is the green cannister? Is that plumbed into the pcv line?

    Better yet, can you just provide some verbal description of what you have setup?
    Maybe a few lines of text to go with the pic.

    How is it working for you?

  19. too much unncecessary