Materials for 2 stroke expansion chambers

Discussion in 'Motorbike Technical Discussion' started by yeo kim moh, Oct 28, 2005.

  1. yeo kim moh

    yeo kim moh Guest

    Hey, I am building my rd350 engine and would like to hands on on a pair
    of tuned exhaust. Anyone has good experience on building 2 streok
    exapansion chambers. Psl share with me. Thanks!

    yeo kim moh, Oct 28, 2005
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  2. yeo kim moh

    Ed Cregger Guest

    Search for a copy of "The Two-Stroke Tuner's Handbook", by Gordon Jennings.
    First published in the seventies, IIRC.

    Ed Cregger
    Ed Cregger, Oct 28, 2005
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  3. You can build one I suppose, but you should really consider buying one. The
    amount of engineering you need to do just isn't worth it even if you valued
    your time at $0.50 per hour. You would be time, money, and effort ahead
    getting a part time job to pay for toys. Let the engineers with the
    modelling programs, dynos, and more do what they have trained for years to
    do. Just reap the benefits.

    R. Pierce Butler, Oct 28, 2005
  4. yeo kim moh

    Ed Cregger Guest

    Jennings book provides schematics for different expansion chambers and the
    geometry/algebra needed to change them for different applications, IIRC.

    Some folks just like to build things. I do.

    Ed Cregger
    Ed Cregger, Oct 28, 2005
  5. yeo kim moh

    Leon Guest

    I had one of those new, back in '74 or so, and fitted a nice pair of
    expansion chambers made in the USA - I had to go up a *lot* on the carb
    jet sizes. They were made out of mild steel, painted black, and tended
    to rust rather badly. A lot more power (and noise)resulted. They had
    glass fibre packing in the outlets, to make them a bit quieter.

    Leon, Oct 28, 2005
  6. yeo kim moh

    monk Guest

    I'm working on a '74 RD350 right now, and have almost a complete parts
    bike if you end up needing anything for it, post here and I will see
    if I can help. In regards to your post, I have an extra set of the
    chrome stock pipes if you give up and need to replace yours.

    monk, Oct 29, 2005
  7. It could be that i am wrong. Maybe they are easier to make than they

    R. Pierce Butler, Oct 29, 2005
  8. yeo kim moh

    the fly Guest

    Production racers in the late '70s-early '80s found that the
    stock RD mufflers made pretty decent expansion chambers. They just
    cut off about half the length of the stock baffle tubes. That, along
    with some cylinder porting and proper carb jetting, gave a pretty
    respectable power increase.
    the fly, Oct 29, 2005
  9. yeo kim moh

    Ed Cregger Guest

    Only if you want them pretty and you have the necessary gear. <G>

    Ed Cregger
    Ed Cregger, Oct 29, 2005
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