Here’s the final assembly of the sleeve drive crank, sprocket and drive pin. Finally looking like a proper engine component! The three holes in the sprocket are to allow it to be removed, rotated 120° and refitted. With the 44 teeth not being divisible by 3, this provides a finer valve timing adjustment than jumping a whole tooth.

Until the patterns arrive that’s all of the machining completed. Time to look at that gearbox and decide whether I can make it work for me.