Eng Cap vs Prop Dia SI



http://www.paddleducks.co.uk/smf/index.php?action=downloads;sa=view;down=346

A metric version of Malcolm Beak's engine size versus propellor diameter.  I have had this graph in the book Scale Model Steamboats (page 68) for a couple of years and never understood the formula.  It has no power shown at all.  In Malcolm's August 1992 Model Boats article in the download section of this site the power is unreadable.  I had been trying squares when my partner finally figured it out that it was the cube of the prop dia.