I had this idea on on how to modify a Bill Marvin type chart
to better illustrate the equivalence of a one rotor 650cc
"displacement" to that of a 650 cc per cylinder four stroke
two cylinder engine. Total displacement of the 2 cyl. piston engine is
1300 cc. The areas of the colored blocks are equal to each other
and are proportional to the displacement of the chambers.
In order to do this I had to make the shorter piston blocks taller to keep
the area the same as the longer rotary engine blocks while keeping
the timing the same.

Note that they both fire once per rev as indicated by the
red tick marks.

I hope this clears things up.

Paul Lamar ...No rotor no motor.

Hi Paul,

It might help to add a note to this first graph stating the total line
length represents an EQUAL number of e-shaft/crankshaft revolutions (
this may be unclear due to all the small numbers under the rotary's
line). And if you ADD all the blue "inhales" for the single rotor's
motion you get 6 times 650cc or 3900cc of air displaced. Now if you ADD
all the blue "inhales" for the twin piston's motion you get 6 times
650cc or 3900cc of air displaced. And it all happens in the SAME UNIT OF
TIME. But we all knew that  : )      Dave M

That sounds like a good idea. I'll think about it.
Perhaps I will just cut and paste the angle line under each
cylinder. that is pretty easy to do.

Paul Lamar ...No rotor no motor.

The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://www.rotaryeng.net
Copyright 1998-2006 All world wide rights reserved.