Unfortunately I could not find a Napier Nomad in the RAF museum
  but they did have the precursor engine called
  Sabre III. The turbo compound Nomad holds the worlds record
  for the most efficient internal combustion engine ever built.
  Like the Wankel rotary engine it had no conventional poppet exhaust
  valves with the associated kinetic energy losses. Like the Sabre the Nomad
  had sleeve valves.

  Paul Lamar In London

         

Looks like it has only a few more parts compared with the wankel engine.

Brian Trubee

Like maybe a million :)

Paul Lamar