The de Pietro (Oops, didn't realize that I didn't get a new window when I hit reply so I could refer to the actual text, so I appologize if I've mispelled the target.
) vaguely reminds me os the Wankel engine with the three pointed rotor that Masda used quite a few years ago. Had a 2nd cousin in California that put 150,000 miles on her her's.