For all the old crowd here that used to discuss displacement of the rotary,
have a look at this animation:
http://mikesdriveway.com/misc/radialrotarycomparison.gif
The engine in the centre has 2 banks of 3 radial pistons (1 bank only
shown). Each piston is 654cc swept volume and expands over 270 degrees. If
we count all cylinders it is a 3.9 litre engine but it only inducts 2.6
litres per 2 revs. What is the displacement of this engine?
