Posted by An Uneducated guess on May 06, 2002 at 13:49:59:
In Reply to: Rotax valves posted by Greg Crider on May 06, 2002 at 13:29:05:
The ports on traditional rotors are more oval shaped and in many cases reduce the bore through the valve set. The Rotax valves use CNC technology to produce perfectly round ports, thus no reduction in the bore size (more like a piston valve). From what I can tell the Rotax valves are not as large as other rotary valves that have round ports (Bach Bass Trombone valves for instance). Other than that I’m not sure what makes them so unique that they deserve to be patented.