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DYI Breather

Discussion in 'Norton Commando Motorcycles (Classic)' started by swooshdave, Apr 20, 2019.

  1. swooshdave

    swooshdave

    Joined:
    Apr 15, 2009
    [​IMG]

    Yes, I know you can just buy a lovely breather but just like the headsteady sometimes there’s more satisfaction in making something.

    While there are tons of options for reed valves I’m thinking of keeping this British (or wherever Triumph sources these parts). As @grandpaul and anyone with a modern Triumph knows the first thing you rip off is the emissions crap. And look what’s inside... a pair of lovely reed valves. I have some of these but I gave them to my brother so instead of shipping them across the country it’s easier just to ask locally. More than likely they are sitting in someone’s garage taking up space. So that’s what I did and someone sent me this from their 06 Scrambler. He wouldn’t even let me pay shipping.

    The housing is different from later bikes but for now this will suffice. The reed valve part is the same.

    Unlike @grandpaul the plan here is to mount this to the back of the case. A friend of mine who modified my cases is also building a Combat engine so I’m helping him with a proper breather. Since he has a massive machine shop I don’t think he’ll have much of a bother with something like this.

    [​IMG]

    [​IMG]

    Although we won’t actually use this part I’m thinking the housing will be something like this part but with some way to mount to the case. Design plans to follow.

    [​IMG]

    Side note: I had a twinge of guilt destroying this part. 40 yrs from now they will probably be hyper rare and worth thousands on eBay.
     
  2. Tornado

    Tornado VIP MEMBER

    Joined:
    Dec 5, 2017
    Got one of those in my storage locker. Been thinking of tearing apart to make a Norton breather. Keep us posted on what you do.

    That said, did a Google for reed crankcase breather valves...loads of designs for cars/bike...with the bike ones being 10-20x the cost for some reason.
     
  3. swooshdave

    swooshdave

    Joined:
    Apr 15, 2009
    Because there’s very little reason for a breather for four or more cylinders. Crankcase volume is relatively constant due to the alternating cylinders.
     

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