Page 3, revised to add animation 6/11/99

From the above table, we have plotted the paths of the power piston, B(p) and the displacer, A(d).The area of the graph above the displacer plot represents the hot volume, while the area between the displacer and piston represents the cold volume. Although in the Rhombic Drive, the piston and displacer motions are not sinusoidial, they do follow similar paths. 
   In the graph, it is a bit hard to determine the exact phase angle, but reference to the table shows it to be very nearly 60 degrees, with the displacer leading the piston.
   I knew from the plot that the compression ratio of this engine was somewhat higher than the usual engine, and Richard opined that it was so high that the engine would not run. On completion, I found that the compression was indeed high, so much so that the engine was difficult to turn over. But on its initial test run, it did indeed run, and quite well. So in this case theory and practice came together successfully.

A(d) = Displacer position, B(p) = Piston position, G = Clearance between piston and displacer