Hi!: you may know from Kenichi Yamamoto books, from SAE papers 710581; 720466, by Yanmar Diesel, from Wankel News nē 64, pages 22-26, by Reiner Nikulski; from patent ES445486, Jose-Ignacio Martin-Artajo; that Recess Shape counts, and counts a lot. Attached please find an image, from 'Motor Trend Mini Manual', 'The Wankel Rotary Engine',

about the different Rotor shapes Rolls-Royce tested when working in their two-stage Compression Ignition (Diesel) Wankel RCE. Salut +

 

really neat! i wonder what a direct injection rotor would look like from Mazda, the piston in the piston engine changed pretty radically. i would expect the rotor too as well.