Blows out oil

Discussion in 'Engine/Drivetrain' started by tacobo670, Sep 12, 2014.

  1. tacobo670

    tacobo670 Addict

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    can someone help me with this.... i recently removed the vent tubes on the valve cover and replaced them with the little K&N filters. The front one seems to be blowing out oil, but the rear one (for the PCV) does not blow out oil. I understand the PCV is meant to be pulled back in to the intake plenum.... but I've seen several other trucks with same setup and there is no oil blowing out.

    so..... What could be the cause of this? i would hate to assume blow-by from the piston rings. but I have not done a compression or cyl leak down test
     
  2. White Trash

    White Trash Toyotaholic

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    Typical blow-by. Simple fix is to put the PCV back into operational condition and leave the other filter in place.
     
  3. Litneon

    Litneon Super Moderator Staff Member

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    Or run a catch can. My turbo motor covered the entire bay before I installed the catch can.
     
  4. White Trash

    White Trash Toyotaholic

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    I did both on my 78. The can even had a drain on the bottom to empty it. :D


    [​IMG]
     
  5. tacobo670

    tacobo670 Addict

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    cool. thanks guys.
    thats what i figured. not willing to put back the PCV hose -disrupts "clean" air. i have the equipment for a catch can, just never installed it yet. i guess ill have to install it then.

    so if it is blow-by .... does that mean im loosing compression? (havent checked that yet) my assumption is -YES most likely.

    and to "white trash" , nice setup. never seen a single carb side setup before. ofenhauser?
     
  6. White Trash

    White Trash Toyotaholic

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    The pcv won't have any effect on clean air and the engine will have a bit more power since there will be a vacuum on the crank case to help seal the rings.


    That was a cannon single intake with a 45DCOE9 on it. I've only heard of one other intake like it but unfortunately I sold the truck with that setup still on it.
     
  7. Litneon

    Litneon Super Moderator Staff Member

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    Theoretically, yes. Blow-by would be lost compression.

    Is it normal? Also yes. Even new rings won't seal perfectly, although gapless rings are very close.

    Will you see an increase in power by replacing only the rings when you have blow-by? Not noticeably, unless it's really really bad.

    Either put it back the way it was, add a catch can, or just live with it. The added vacuum can help seal them at idle and part throttle, but at full throttle, there isn't any vacuum, so it doesn't help with WOT power.
     
  8. tacobo670

    tacobo670 Addict

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    ....more power

    .... not affected at WOT

    .... more power less power....? my target is -least restriction (dirty air) at WOT.
     
  9. Litneon

    Litneon Super Moderator Staff Member

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    Well, think about it. The power gain you could get is likely minimal to begin with. You are talking about a 116 hp beast... (give or take)

    If the vacuum is the source of better sealing rings, then at or near WOT when the chamber pressures are near atmospheric, there isn't any vacuum to speak of. Hence no extra sealing, and no extra power.

    Down low, maybe. But if the engine is making 130 lb/ft. of torque at 2500 rpm, that's only +/- 61 hp. Do you think you'll notice a couple percent increase in power? Keep in mind that max torque is usually made with the TB fully open. Part throttle, you'll make less TQ, resulting in much less HP.

    As far as "dirty" air, yes, a catch can will help with dirt, ie. oil in the airway. If you mean "dirty" as in restrictions, there will be no difference. If you are pulling so much oil that the plugs are fouling, you could run a step higher heat range to keep them clean. Read up on that first, before changing heat ranges.
     

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