Russell Sutton has built a 9-cylinder radial engine from a Honda XR-600 motorcycle engine.

-It does not have a cam plate for timing, as is usual in radials, and we can guess that it is an engine made up of nine Honda motorcycle engines, with their nine crankshafts, meshing on a central axis.

“Russell next to his compound engine”

-In the above photo we can clearly see the proportions of the cylinder and the crankshaft gear, so the length of the connecting rod is normal.

“The engine without the front cover, showing the 9 gears”

-For the distance from the cylinder to the central axis, if it were a normal radial, the connecting rods would be of an exaggerated length, for the cylinder stroke that is guessed to be much shorter.