Exhaust Flexible exhaust pipe

Discussion in '2-Stroke Engines' started by DutchDude, Aug 13, 2007.

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  1. DutchDude

    DutchDude Guest

    I have done my searches, but I can't find any info on the flexible pipe used in the Hornet:


    Does anyone have any ideas on what kind of pipe to use?

    I have thought about perhaps using the flexible ducting they use for electrical cables, but I am worried about exhaust leaks? Perhaps I could cut the exhaust after the downward bend put in the electical flex duct on with a clamp, then mount the rest of the exhaust pipe next to the sprocket?

    Let me know if you have better ideas?

  2. azbill

    azbill Active Member

    I believe that hornet made his pipe from conduit
    it can be welded, but you need to grind off the galvinizing before heating or it will give off hazardous fumes
    (bye-bye brain cells:rolleyes:)
    I always thought using fexible copper to get the right config, and then transfering that shape to steel would work well
    Last edited: Aug 13, 2007
  3. FYI - Flex pipe adds restriction to the exhaust (as opposed to smooth exhaust pipe) but it does make exhaust routing easier..
  4. azbill

    azbill Active Member

    that's why I said to use it to get the shape you wanted...then transfer to steel
    (not to use it for final pipe)
  5. DutchDude

    DutchDude Guest

    I looked for flexible gas pipe, but the only size that I could find is 3/4" - with an inside diameter of about 1/2". The electrical conduit comes in larger sizes.

    I guess I can weld it if I have to - I just liked the look of the flex pipe.

    How much extra restriction would we be talking about? Enough that it would matter?
  6. gone_fishin

    gone_fishin Guest

    from several years of auto-exhaust experience: some flex tube can actually work to further "restrict" your exhaust...turbulance from the ridges hampers the flow.

    i think "hornet" used more of a smooth-bore style of flex that prolly works ok...but if i needed an easy but nice-looking custom pipe, i'd go with conduit.
  7. Flex pipe and.......Fishtail??

    Hi gang, that looks to me like the traditional Whizzer flex-pipe, and fish tail used in the kits prior to 1965.