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Thread: 40 years old today

  1. #1
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    40 years old today

    The Mazda Rotary (twin-rotar) engine that is, not me ...
    http://www.new-car-net.co.uk/Mazda_news.html?id=6881
    http://www.mazda.com/mazdaspirit/rotary/
    Many happy returns
    "A woman without curves is like a road without bends, you might get to your destination quicker but the ride is boring as hell'

  2. #2
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    Happy birthday I guess...
    Lack of charisma can be fatal.
    Visca Catalunya!

  3. #3
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    Hooray for Rotary!!!!
    Honor. Courage. Commitment. Etcetera.

  4. #4
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    What happened to the "Pistons are so overrated" picture with the 787B in the background?

    Happy birthday. It's a shame we don't use the rotary much.

  5. #5
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    Quote Originally Posted by NSXType-R View Post
    It's a shame we don't use the rotary much.
    Speak for your self. I'm going to take a ride just to celibrate.

  6. #6
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    The NSU spyder is already 44...
    "I find the whole business of religion profoundly interesting, but it does mystify me that otherwise intelligent people take it seriously." Douglas Adams

  7. #7
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    has anyone tried to make a diesel rotary?
    Andreas Preuninger, Manager of Porsche High Performance Cars: "Grandmas can use paddles. They aren't challenging."

  8. #8
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    Quote Originally Posted by clutch-monkey View Post
    has anyone tried to make a diesel rotary?
    not to my knowledge...
    "I find the whole business of religion profoundly interesting, but it does mystify me that otherwise intelligent people take it seriously." Douglas Adams

  9. #9
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    i wonder if it would be worthwhile - or possible?
    i was just thinking that it might deal with the rotary's flaws of fuel consumption and low torque, while being a high revving diesel?
    Andreas Preuninger, Manager of Porsche High Performance Cars: "Grandmas can use paddles. They aren't challenging."

  10. #10
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    Quote Originally Posted by clutch-monkey View Post
    i wonder if it would be worthwhile - or possible?
    i was just thinking that it might deal with the rotary's flaws of fuel consumption and low torque, while being a high revving diesel?
    one of the problems of the engine has always been the sealing of the edges of the rotor. Diesel engines need no ignition system, but work on high compression. I am afraid that applying this same high compression in the wankel chambers will again put problems to the seals.. (if this is bare nonsense I'll be the first to stand corrected )
    "I find the whole business of religion profoundly interesting, but it does mystify me that otherwise intelligent people take it seriously." Douglas Adams

  11. #11
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    Quote Originally Posted by henk4 View Post
    one of the problems of the engine has always been the sealing of the edges of the rotor. Diesel engines need no ignition system, but work on high compression. I am afraid that applying this same high compression in the wankel chambers will again put problems to the seals.. (if this is bare nonsense I'll be the first to stand corrected )
    if you;re referring to the apex seals i was under the impression ceramic ones worked quite well for high performance rotaries? if they can build xxxhp rotary engines couldn't that work could be adapted to create the strength a diesel would require
    i'm no engineer...
    Andreas Preuninger, Manager of Porsche High Performance Cars: "Grandmas can use paddles. They aren't challenging."

  12. #12
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    Quote Originally Posted by clutch-monkey View Post
    i'm no engineer...
    neither am I....
    "I find the whole business of religion profoundly interesting, but it does mystify me that otherwise intelligent people take it seriously." Douglas Adams

  13. #13
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    I am
    You only get one seal with a rotary unlike a piston which may have up to 3 , each doing a different job. The rotary apex seal has to do all.
    Next .... Apex seals don't have a flat wall to seal to, so harder to start with and on top of that pressure causes a seal to flex which opens up the seals. So for higher compression you need VERY high tip forces. WHICH sadly increases friction losses and wear. Thsi then means it's not possible to use radial intake/exhaust and must use side ... which creats more of an issue with sealing on the rotor edges

    hence all why turbo charging a rotary tends to require expensive parts and regular replacement !!


    and finally .... wankel compression ratios are determined by the chamber SHAPE. Not the stroke as in Otto. So in practice 10:1 is about the limit though Japanese designers have surmised a theoritical 15:1 ("Rotary Engine" - Kenichi Yamamoto)
    "A woman without curves is like a road without bends, you might get to your destination quicker but the ride is boring as hell'

  14. #14
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    so ..it's not really possible with current tech?
    Andreas Preuninger, Manager of Porsche High Performance Cars: "Grandmas can use paddles. They aren't challenging."

  15. #15
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    Quote Originally Posted by Matra et Alpine View Post
    I am
    You only get one seal with a rotary unlike a piston which may have up to 3 , each doing a different job. The rotary apex seal has to do all.
    Next .... Apex seals don't have a flat wall to seal to, so harder to start with and on top of that pressure causes a seal to flex which opens up the seals. So for higher compression you need VERY high tip forces. WHICH sadly increases friction losses and wear. Thsi then means it's not possible to use radial intake/exhaust and must use side ... which creats more of an issue with sealing on the rotor edges

    hence all why turbo charging a rotary tends to require expensive parts and regular replacement !!


    and finally .... wankel compression ratios are determined by the chamber SHAPE. Not the stroke as in Otto. So in practice 10:1 is about the limit though Japanese designers have surmised a theoritical 15:1 ("Rotary Engine" - Kenichi Yamamoto)
    at least my general direction of thought was not that far off the mark
    "I find the whole business of religion profoundly interesting, but it does mystify me that otherwise intelligent people take it seriously." Douglas Adams

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