So in side that soft, squirmy aluminium case ( as Dennis put it ) there is a big heavy lump of steel rotating. The crankshafts for C1, C4 and -46 are similar the most obvious difference being their length. From the front counterweight a C1 and C4 crank sticks out about 11.5 inches. The -46 aircraft crank sticks out about 16 inches. I do not have an earlier Weight aircraft crankshaft to measure but I think it would about the same length as the -46. There is another important difference. Pleaser look at the (hopefully) attached photos. Two pictures compare a C1 crank to a -46 crank, while the third picture is a C4 crankshaft. There are two bearings on the shaft inside the nose case of these radials.
Note that the shorter C1 crankshaft (like Wright aircraft engines) have both bearings retained by a nut on threads cut into the shaft. If you look closely at the top view you can see the thin nut next to the bearing on the C1 crank. Note that the -46 crankshaft does not have this threaded portion to retain the inner bearing. You can see on the photo of the C4 crankshaft that the inner bearing is held in place by a sleeve which is pushed in place by the outer bearing and held by the outer bearing nut. Now could some of the metal wizards in this forum rework a -46 crankshaft into an ultra rare C4 crankshaft, your comments always appreciated!
