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Oil tank Venting

Discussion in 'Norton Commando Motorcycles (Classic)' started by olympus, Apr 4, 2019.

  1. olympus

    olympus

    Joined:
    Aug 5, 2017
    Hi Guys
    When either BMC or K&N conical air filters are used where do folk vent the oil tank into? ... atmosphere, into a bottle??
     
  2. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    Bottle.
     
  3. illf8ed

    illf8ed

    Joined:
    Dec 30, 2003
    If you have a ham can air filter originally (not the black plastic thing of 850 MkIIa and MkIII) return to the original and use a full size K&N air filter. Air cleaner modifications eliminate good features such as a place to attach the ignition switch. Chrome the front ham can plate and it looks like a custom air cleaner for a 60's muscle car. Stainless surround is a nice touch also.
     
    xbacksideslider likes this.
  4. ashman

    ashman

    Joined:
    Jul 11, 2010
    On my Featherbed I run my breather from the motor as well the oil tank breather into a 1 ltr with a screw top catch bottle that sits in between the rear engine mounts the two hoses fit tightly in the screw top but the hoses go to the bottom of the catch bottle and a few breath holes at the top of the catch bottle to let out excaping air, been like that for 37 years now.

    Ashley
     
  5. lazyeye6

    lazyeye6 VIP MEMBER

    Joined:
    Feb 28, 2014
    I must be doing something wrong. (My wife can attest to that)
    I have a Mikuni with a K&N filter. I left my oil tank breather attached
    to it's spigot on the ham can filter backing plate. I get no oil, splooge,
    or even enough vapor out of it to attract any dirt. Yes, I have verified
    that the hose isn't blocked. I never fill the oil tank higher than half
    way below the high mark on the dip stick. Oh!, I have a Comstock
    sump reed breather.
     
  6. eskasteve

    eskasteve VIP MEMBER

    Joined:
    Sep 24, 2012
    On my 73 850 I vent to a small bottle that's wedged between the battery and the rear air cleaner box plate thingy. With the Mike's XS crankcase reed valve and 6500 miles on my rebuild I get very little to zero ooze in the catch bottle. Long fast 75-85mph freeway drones puts a misty coating inside the bottle. Nothing in normal operation.
     
  7. ashman

    ashman

    Joined:
    Jul 11, 2010
    In 37 years of having my catch bottle I have only got a dribble of oil in the bottom of the bottle, its more air from the tank and motor that excapes into the bottle not oil and with the reed valve on my motor no air gets sucked back into the motor.

    Ashley
     
  8. Lineslinger

    Lineslinger VIP MEMBER

    Joined:
    Feb 26, 2017
    F7F35B1F-8E21-474D-BF29-70D44FAC1B06.jpeg CD50AAF8-2512-4743-A39B-80354F236F9B.jpeg

    I installed Mikes reed valve and vented the oil tank....a very small amount of fluid makes it to the reed valve but never further.
    I ran a catch bottle on a couple of high performance automobile engines with very little if any fluid trapped as long as the PCV was in place.
     
    Last edited: Apr 7, 2019
  9. olympus

    olympus

    Joined:
    Aug 5, 2017
    Where did you get the breather filter from please??
     
  10. lazyeye6

    lazyeye6 VIP MEMBER

    Joined:
    Feb 28, 2014
    What does the breather filter, filter?
     
  11. texasSlick

    texasSlick VIP MEMBER

    Joined:
    Jan 2, 2013
    IMO, a catch bottle catches little or no oil unless it is filled with a scrubber media, and the in/out plumbing is arranged to force the crankcase vapour to pass thru the scrubber media.

    Oil is carried by the crankcase vapour as a mist or "fog", and passes thru, and exits the bottle without being deposited in the bottle unless a scrubber media is present.

    Slick
     
    Last edited: Apr 7, 2019
  12. Lineslinger

    Lineslinger VIP MEMBER

    Joined:
    Feb 26, 2017
    Summit Racing. They offer a wide variety of size and filtration applications. Their shipping costs suck, check Fleabay too.

    Any vapor, fluid or particulate passing through the crankcase and making it through the the oil tank or beyond. I installed it primarily as CYA protection.
    Call it a vapor filter...and I wanted a secondary level of protection from oil getting spewed all over the rear half of my bike. Just another level of control.
    Texas S offers a realistic insight.
     

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