Valve cover breathers and Catch cans

Discussion in 'Engine Topic' started by Seventy1ProTour, Dec 2, 2017.

  1. Seventy1ProTour

    Seventy1ProTour Member

    Oct 18, 2017
    Huntersville NC
    Hey all,

    I was just trying to see what people are running for crankcase ventilation and/or if you are using a catch can. Ultimately, if my application needs it.

    Engine: 355, forged JE Pistons, forged crank, worked heads, comp mild Cam, 10:1 compression.

    I'm currently running two breathers on the driver valve cover and they tend to get messy quick. Wanted to see the input on using a vented catch can.
  2. COPO

    COPO Veteran Member Lifetime Gold Member

    Sep 15, 1999
    Ontario, Canada
    Home made oil catch can from a Seafoam can. Inside is 1 stainless steel scrub pad. JB Weld works well on the brass connections.




    Goodwrench1965 and MotionClone like this.
  3. Z28zz383

    Z28zz383 Veteran Member

    May 11, 2012
    Some don't like them, but I run a pcv valve on the pass side going to manifold vac. this stock type set up keeps the engine a little cleaner inside bringing in fresh air. A round oil breather on the driver side. No oil leakage seen.
  4. muscl car

    muscl car Veteran Member Lifetime Gold Member

    Running a Pan Evac set up !!!
  5. MotionClone

    MotionClone Veteran Member

    Jan 20, 2014
    away from the crazies

    love home made stuff...great job
  6. Seventy1ProTour

    Seventy1ProTour Member

    Oct 18, 2017
    Huntersville NC
    I'm also running moroso tall covers on my crane 1:6 rockers. Need to see if there is a prevision on the pass cover for a pcv. I def think a catch can will help me, but ventilated for sure. Any recommendations on how you'd run the lines? The previsions on the driver cover are large openings.
  7. Damon

    Damon Veteran Member

    Nov 16, 2000
    Philly area
    If you're not going to run a PCV system which is, quite frankly, the quickest route to victory for most mild street cars (that are NOT boosted), then you can get some cheap MOPAR-style breathers (sealed breathers with a vacuum hose nipple pointing 45* out the top) and run hoses from them over to a cheap remote catch can with a breather on top.

    Example of the breather I'm talking about (not the only ones available- the choices are nearly endless):

    I've run this system on multiple street-strip type cars in the 10s, couple in the 9s and one now one almost in the 8s. Street-driven cars. Nitrous, blower, turbo... it works with all of them because it doesn't give a damn what happens in the intake. It only knows how to get blow-by gasses from the valve covers (crankcase) over to an atmosphere-vented catch can. Depending on how well your rings are sealed up (and how well baffled your valve covers are from the rockers chucking oil up at it) depends on how often you have to drain the oil out the petcock on the bottom of the catch can.

    It's simple, it's cheap, it works.

    If you're running vented breathers only in both valve covers like you are now, that's fine, but you're going to be cleaning oil off the valve covers every 10 minutes. This is the functionally-equivalent system that gets you away from all that valve cover mess.
    Seventy1ProTour likes this.
  8. Seventy1ProTour

    Seventy1ProTour Member

    Oct 18, 2017
    Huntersville NC
    Thanks for the advice, everybody.

    I will purchase and run those sealed breathers over to a vented catch can.
  9. mrdragster1970

    mrdragster1970 Veteran Member Lifetime Gold Member


    The evac will give you a tiny tiny amount of free HP if you don't have to pass an inspection.
    More & more guys are going with electric vac pumps for mild stuff,
    or a sealed system into a puke can if you have too much HP for it to handle.

    A pcv is horrible for hot rods with an increased cylinder pressure!!!

    muscl car likes this.
  10. camaro71/holland

    camaro71/holland Veteran Member

    Aug 27, 2003
    The Netherlands

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