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Crankcase breather

  • 28 Jun 2023 2:53 PM
    Quote
    Message # 13221262
    Daniel Quinn

    Hey guys,


    Has anyone tried using a modern PCV valve instead of the disk for our breathers?  I am having some issues with my stock setup.  Even without a gasket the disk seems to keep getting stuck closed (the slot the disk rides in is a little worn) and it is causing pressure buildup in the case and tranny.  

    I see that KIWI sells a setup that looks like it uses a standard PCV valve from the auto parts store. I also read an interesting article at perfomanceindian.com on a breather system that used a "crank-vent".  

    Before I go down this road, has anyone had success using a modern PCV valve?


    Thanks for any info.

    Daniel
  • 28 Jun 2023 6:53 PM
    Quote
    Reply # 13221387 on 13221262
    Manny

    Hi Daniel,
    I have not tried this with engines with total loss lubrication but in the later engines with dry sump lubrication I've often installed PCV like Crank Vent and they work very satisfactorily.

    Right now I'm building a (fast) Standard Scout motor and I'm going to build a fully closed vent as described on the Performance Indian page.
    But I haven't got any experience with that yet.

    All the best
    Manny
  • 29 Jun 2023 1:17 AM
    Quote
    Reply # 13221491 on 13221262
    Andrew Newstead

    Is there a simple test I can do on my breather to confirm that it works as I am having a leak issue that may be a result of over pressure due to a faulty vent?
  • 29 Jun 2023 4:41 AM
    Quote
    Reply # 13221512 on 13221491
    Philip Jenner
    Andrew Newstead wrote:

    Is there a simple test I can do on my breather to confirm that it works as I am having a leak issue that may be a result of over pressure due to a faulty vent?

    Yes   put a piece of plastic tube on  and blow suck   on it   it should  close of as you blow   ,  another trick is   put a balloon on the pipe  It should  blow up    to a degree 

    regards Phil
  • 29 Jun 2023 10:25 AM
    Quote
    Reply # 13221659 on 13221262
    Daniel Quinn

    That's the test that showed me mine is not working properly. When first installed with a tiny bit of yamabond as a gasket (no paper), it works as it should.  I blow into the tube and it blocks closed.  Tiny bit of suction and I can feel it open up and some air moves.  It goes back and fourth a few times then sticks closed.  The casting at the end of the breather tube must be worn out a bit and letting the disk get stuck.  Anyone know of a good source for a reproduction tube/casting?  I would have thought that walker would have one but it does not look like they do. 


    Daniel
  • 29 Jun 2023 1:00 PM
    Quote
    Reply # 13221759 on 13221262
    Tim Raindle (Administrator)

    Stick a rubber hose over the end of the pipe. Then you can suck and blow on the pipe.  If it is working really well and everything is very quiet you can here them flutter slightly with a stethoscope . Easy for them to clog up, especially with a touch of over oiling, can become a regular check on item. Once rings bedded in and oiling sorted, can work effectively for quite a while.

    Daniel, I have never had much success with any modern vent type upgrade, the couple of chiefs I have had them on have had breathing issues removed when the modern vents were removed and put back to standard. Let us know how you go if you try it 
  • 29 Jun 2023 1:40 PM
    Quote
    Reply # 13221775 on 13221262
    Daniel Quinn

    I may give a modern PCV valve a try.  It won't cost much and at least I can provide the group with some data.  

    Here is a link to a video of the bike running and you can se little bubbles being pushed out near the couch arm.  Sure looks like a pressure buildup to me.  Let me know if anyone thinks I have a different issue.  As I stated when I check my breather disk it works some times but gets stuck some also.  If I could find a good reproduction of the breather I would go that rout as it looks so much better and original.

    https://youtu.be/ZkGDVaohGx4


    Let me know what you all think
  • 30 Jun 2023 7:07 AM
    Quote
    Reply # 13222082 on 13221262
    Tim Raindle (Administrator)

    certainly looks that way. is the tiny breather vent hole in the trans tower cap clear ? has the bike got a  seal on the drive sprocket side of the tranny ?
  • 30 Jun 2023 11:49 AM
    Quote
    Reply # 13222203 on 13221262
    Daniel Quinn

    I have not checked the genny tower hole.  I am assuming when I remove the tower the hole will be evident?  Anyone have pictures of what I am looking for that would be very helpful.

    Danny at Laughing Indian put the tranny together so I would assume he has a seal on the drive side but what I do know is that is the area where oil is being pushed out.  There along with the genny drive pulley.  


    This is a new issue that only started this season.  That's what makes me think it is the breather valve getting stuck closed.  

    Daniel
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