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Boosted 93 Cobra popping PCV out - need input!

Discussion in 'The Blower Bistro' started by Liv4Spd, Aug 17, 2014.

  1. Liv4Spd

    Liv4Spd New Member Established Member

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    *Cross posting from another forum thread due to lack of responses*

    Hey guys,

    Looking for a little direction here..

    A little background, the Cobra's got about 34k on it and been non-oped for the past 3 years due to 'life' - been looking at getting her back on the road. Motor has an older V2SQ set up w/ 6lb pulley, Anderson Power Pipe, and full exhaust. Most everything between the throttle body and headers is bone stock - total boost peaking about 9lbs.

    Pretty clear my issue is to much crank case pressure due to the SC - only pops the grommet/PCV out (erupting oil all over her otherwise pristine firewall.. :cryying:), no problem with this happening outside of boost. Clearly need to relieve the pressure, but can't cap PCV and use the more common breathers due to shitty CA emissions/visual inspection BS.

    So, with the intent to relieve the pressure while maintaining a PCV system in place, I purchased some hose and tried to relieve the pressure by: T-ing the vent hose (feeding into the PCV/grommet) and running the 'vent-line' under the intake; inline too T-ing off of the bung on the oil feed (top of passenger side valve cover); continuing on to the Steeda oil separator kit, ending at the blue anodized bung to the back of the Anderson Power Pipe, post MAF. The intent, re-feed the air into the cycle while keeping it metered, a closed system.

    Below is a birds-eye view of the engine bay, post work. You should be able to see the BLUE line popping out from underneath the front of the intake, and to the left of the MSD Distributor. From there, it T’s off to the Oil fill bung, and continues down under the SC to the Oil Catch on the fender wall. From there, it passes underneath the SC feed on to the back of the Power Pipe.

    See pic: [​IMG]

    Here’s my problem… it still blowing the PCV/grommet out blowing oil onto the firewall. With that being said, the RED circle is where I started the relief line… should it be where I have the GREEN star? Or, am I completely off base with this whole thing. Should I just be running a line from the Oil-feed/bung to the oil separator and leave everything alone behind the intake? I’m pretty sure I’m just over thinking this.. need a second opinion here – enter svtp.com :shrug:

    See pic: [​IMG]

    Sorry for the long winded post.. but want this to be as clear as possible so you folks can give as informed an opinion as possible.

    Thanks!
     
  2. beaterbike

    beaterbike Member Established Member

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    Your description is confusing . But it looks like you are trying to relieve crank case pressure between the pcv valve and the intake ? Where you need to be is the valve cover to power pipe . When you are out of boost the air comes from the powerpipe to the pass valve cover through the crank case then the pcv valve and finally into the intake . The pcv valve blows out because the valve cannot flow the excess crank case pressure so relieving it after the valve won't help. You need a larger vent from valve cover/crank case to power pipe . Also if the grommet is hard from age it may not be holding the pcv in place. And finally do you have too much blow by from the blower or bad ring seal ?
     
  3. Liv4Spd

    Liv4Spd New Member Established Member

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    Location:
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    Beaterbike,

    I've done leak-down test and seals were good. I think all components are good-to-go.

    I don't know if this will help.. but here's a rough diagram of how the vent line is currently set-up:
    [​IMG]

    Starting at the Green star near the top of picture/intake is where I T'd into the vent line (pic in initial post "Red circle"); along down under the intake to the next green star (which indicates the second T-off point) to the valve cover bung; then out underneath the supercharger to the oil catch; through the oil catch and back into the intake path (post MAF).

    BTW - you can click the pictures to download a non-compressed img for easier viewing.

    So, I was trying to relieve the pressure at two points - the main line in the back of the intake & the oil fill/cap bung. The throttle body bung is currently capped.

    What I think you're saying is... forget everything at the back of the intake? Start the line at the bung on the Oil Fill cap (valve cover), through the oil catch, to the PowerPipe?

    Cheers
     
    Last edited: Aug 19, 2014
  4. mike dj

    mike dj Master Mechanic, fabricator and Drag Racer Established Member

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    Delaware
    You need to put two valve cover breathers on it one on each side in a staggered configuration. Make sure you have a new PCV valve,grommet,and the factory PCV wire mesh filter.
     
  5. SVTORANGE

    SVTORANGE Active Member Established Member

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    Sounds like your building up some serious crank case pressure. I would put a oil breather in that line to relieve the pressure
     
  6. VA-Mach1

    VA-Mach1 Active Member Established Member

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    Make sure you have the correct pcv. I believe the Cobra S/C pcv's have a built-in one way valve that closes under boost to keep your problem from happening. It should be a EV111.
     
  7. 01yellercobra

    01yellercobra AKA slo984now Established Member

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    Run breathers until it's time for smog. Then swap to the PCV. You're building major crank case pressure. It happened to a buddy of mine with his 93. Exact same issue. Every time we stopped he'd pop the hood and put the PCV back. A built short block was his fix.
     

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