> > > >>  Mark wrote:

 > > >>  Another way to do the same thing is to import the bit map into a CAD
 program
 > > >>  (most support this) and then trace the rotor housing and ports over
 it,
 > > >>  scaling the whole thing to a know dimension. If you then print out
 to scale
 > > >>  on an A3 (2xUS Letter is??) lasar printer, you should have a paper
 template
 > > >>  accurate to within a mm or less.
 > > >>  Mark Wrathall
 > > >  > www.rotary.microcosman.com
 > >
 > > It did not work for me, but I would really like to receive a cad file
 > > of the rotor housing if you got the time.      Jerry
 >
 Mark wrote:

 Jerry,
 here is the drawing in AutoCAD V14 format scaled to a rotor housing inner
 surface height of 240mm. Measure a housing's long axis  and scale the whole
 drawing, centered on 0,0 to a scale of "your housing measurement" / 240.

 If you need another format like DXF or STL just let me know.

 If you print (at full scale on a lasar printer) the layer "Housing" you will
 get my best shot at the port timing.

 The housing inner surface is not a perfect fit as mine is a mathmatically
 derived trochoid, and Mazda's deviates from that to make it work.

 Scaling the small .jpeg Paul sent out means you end up trying to use a line
 of best fit across the fuzzy scan lines . Unless there is a higher
 resolution scan of that SAE paper out there, and the printed photo in that
 paper is resonably large and high quality, I can see how this is only a
 rough guess. Now you need a photo square on to the port to get the other
 dimension - width.

 We need someone to make a bunch of these with small variations and dyno test
 them to see whether the Le Mans rotary is like a two stroke, and very
 sensitive to small changes in port timing (in which case this method is only
 a rough starting point), or whether the rotary is more tolerant of small
 changes in timing, and breathes easier as the ports get bigger. Any takers?
 :)

 We also need to take into account that the Le-Mans engine was designed for a
 24 service life. Peripheral ports this big may have some nasty durability
 issues waiting.

 Regards,

 > Mark.

  Download the Lemans engine SAE paper Mark. No wear.

Paul Lamar

  Mark,  there was no attachment.    Please send the file as a DXF  to
me at the address below.  Thanks,  Jerry

j-winddesigns@thegred.net

Mark sent a dwg file but I could not load it into R12. I will upload
it as a gif as soon as I can load it into Rhino, export it as
an R12 version and plot it as a gif. Sorry Jerry.

Paul Lamar
 
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