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Quick Oil Catch Can Question

Discussion in 'Engine/Tuning' started by Rossim22, Jan 4, 2012.

  1. Rossim22

    Rossim22 New Member Established Member

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    I'm running breathers right now and not too fond of vapor coming out of the hood vents or through the a/c vents so I bought an oil catch can. I'm wanting to do the passenger side, Question is: From the front of the passenger side valve cover, the tubing goes to the oil catch can, then from the oil catch can to where? My car has always either has catch cans or breathers so I'm not sure how to route it.

    Thanks for any help
     
  2. gregorio

    gregorio Member Established Member

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    you only need the catch can on the (edited by moderator- DRIVER'S) side. 80% of the oil comes from that side. it goes inline with the pcv valve.
     
    Last edited by a moderator: Jan 5, 2012
  3. Rossim22

    Rossim22 New Member Established Member

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    Yeah, so pcv valve to catch can to intake correct?
     
  4. SlowYellow

    SlowYellow Member Established Member

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    Do you mean drivers side? My PCV valve is on that side. That is where mine is mounted.
     
  5. MalcolmV8

    MalcolmV8 Well-Known Member Established Member

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    Other way around. Most the oil comes from the driver's side. PCV valve is also on the driver's side.
     
  6. SnakeBit

    SnakeBit Mid-Life Crisis my ass! Established Member

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    Another thing which makes it difficult to do a catch can on passenger side is that air flow can reverse direction depending on boost or no boost. That will make it difficult for a catch can to work properly (although it can be done).

    On the driver's side, the PVC "tries" to act like a check valve to only allow flow from valve cover to intake. It's that one-way air flow which makes the catch can effective.

    Most catch cans I've seen have a screen at the inlet to the body of the can (looks like very coarse steel wool). Oil condenses on this screen then falls down into the bottom of the can where it collects. If the can is large enough, and has no screen, it can work by utilizing pressure differential between the inlet tube and the body of the can. When the flow exits the inlet tube into the body of the can, it encounters a pressure drop which causes the oil droplets to group together then fall to the bottom of the can. As oil fills the can, and it's empty volume gets smaller, the pressure drop also gets smaller causing it to be less effective. Eventually, if not emptied out, it will stop working altogether.
     
  7. gregorio

    gregorio Member Established Member

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    Yeah I meant to say driver side
     
  8. Rossim22

    Rossim22 New Member Established Member

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    Ok well I'm asking about the passenger side like I stated in the OP. I said nothing about pcv, it was inferred by someone else. My motor is not stock, higher comp and different rings set up for blower + n2o. All of the visible oil vapor is coming out of the passenger side breather so how do I set it up on that side?

    PASSENGER side valve cover -> catch can -> side of ram air intake ? ?

    Yeah I liked the looks of the mishimoto catch can which is very large and uses the pressure with a magnetic drain bolt to filter. However I added some steel wool at the very top to prevent the vapor from going directly into the outlet port
     
    Last edited: Jan 7, 2012
  9. SlowYellow

    SlowYellow Member Established Member

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    You could do one of the JLT Pre-filters and then your RAI. That is a somewhat common setup with a catch can on the drivers side.
     
  10. SlowYellow

    SlowYellow Member Established Member

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  11. Rossim22

    Rossim22 New Member Established Member

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    Seriously? Passenger's side. pasenger's side. passenger's side. passenger's side. passenger's side. I do not want a pre-filter as i dont think it'll be enough
     
  12. SlowYellow

    SlowYellow Member Established Member

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    Ok then jackass. I'm just trying to help you out. It's really not that difficult of a system. Flow path should be as follows: possible oil saturated crankcase air - catch can - vacuum source(ie port on your Ram air intake).
     
  13. Rossim22

    Rossim22 New Member Established Member

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    Ah yes thanks! exactly the info I was asking for.. minus the jackass part. :beer:
     
  14. SlowYellow

    SlowYellow Member Established Member

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    Glad I could be of assistance!
     
  15. MalcolmV8

    MalcolmV8 Well-Known Member Established Member

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    Like slowyellow said. From air intake tube (between mass air and TB) to catch can, to valve cover. It's just like how the passenger's side valve cover is plumbed from the factory except you're putting a catch can.

    Let us know how that works. I'm curious because under normal driving conditions air will flow from the air intake tube, into the passenger's side valve cover, out driver's side through the PCV valve into the intake manifold before the blower and also to a port after the blower (there's a tee fitting) which will be under vacuum in normal driving.
    However when you WOT and go into boost the hose on the driver's side will now go under pressure instead of vacuum. The PCV valve is supposed to stop boost going back into the driver's side valve cover.
    Your crank case now gets some pressure too from blow by which is going to exit on the passenger's side valve cover going into the air intake tube which will now be in a higher vacuum state than before because the TB is wide open sucking in a lot of air.

    So essentially what I'm getting to is the catch can on the passenger's side will experience air travelling in opposite directions depending on normal driving or WOT. Catch cans are made to trap oil in one direction, not both. So make it catch oil in WOT from going into your air intake tube and in normal driving if it gets sucked back into the passenger's side valve cover then I guess that's no big deal. Probably helpful really as it may save you having to empty it.

    Be interesting to see the results you come up with.
     
  16. Rossim22

    Rossim22 New Member Established Member

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    ^^
    According to what you said, why would vapor be escaping from the passenger side vc breather while idling and under normal driving?
     
  17. SlowYellow

    SlowYellow Member Established Member

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    I think that you are confusing his setup with a centrifugal blower or a turbo. His intake tube will never be under pressure due to the location of the blower. The blower is upstream of the tube, so it's always going to have the intake tube under a vacuum.

    Edit: I just read your post again. I believe that the vacuum that is on the intake tube at WOT is going to be greater than the pressure inside of the crankcase. If it isn't, I'd venture to guess that you may have bigger problems, lol.
     
    Last edited: Jan 7, 2012
  18. MalcolmV8

    MalcolmV8 Well-Known Member Established Member

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    Is your PCV system on the driver's side valve cover in good shape and fully functional?

    Just trying to understand here, you say the vacuum in the intake tube is greater than the pressure in the block? "the vacuum is greater than the pressure"? Maybe re-word that one, lost me for a bit.
     
  19. Rossim22

    Rossim22 New Member Established Member

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    The driver's side also has a breather. My builder installed the breathers on both sides, vapor only comes out of the passenger side and neither the builder or two tuners thought it was of any concern, just that there was more blow-by on that side due to the larger ring gaps
     
  20. MalcolmV8

    MalcolmV8 Well-Known Member Established Member

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    OK well the breather and lack of PCV on the driver's side explains the non factory functionality of your passenger's side breather port on the valve cover.
    I don't know why people just pop breathers on. Without some sort of PCV system in place (factory or otherwise) you are never sucking the air out of the block and removing the blow by and the nasty stuff it puts in there. It forms corrosive acids and engine sludge on the inside of the motor even if you change the oil frequently. This can block other small oil passages and cause other problems.
    Just google PCV systems and you'll find all kinds of tech articles explaining the importance of PCV and how they work.
     

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