Mark Wrathall wrote:

The plans I have for the SW92 model wankel have major radius of 28mm and an
eccentricity of 3.5mm for a ratio of 8. The Mazda has a 15mm eccentricity
but I don't know the major radius.

What is the practical R/E ratio range? 8 gives a trochoid very close to an
oval, whereas to my eye the mazda uses closer to 7.

Does anyone know what the offset value (a in the attached formula) that you
need to offset beyond the true trochoid? My feeling is that this value is
greatly exagerated in the attached diagram, and would only be maybe 1/30th
of the major radius, but that is guessing.

Regards,
Mark

13B e is 15 mm R is 105 mm and b is 80 mm.

Apparently the leaning angle must be kept within a narrow range so that
pretty much dictates all other dimensions when scaling the engine.


Paul Lamar
 
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