I have been thinking about the belts and I have decided to use a automotive serpentine belt . I have the pulley set up on a faceplate and I am about to machine it to suit the poly V belt .
I am first going to try using the flat side of the poly v belt , eg, no ribs , I will machine the pulley flat . If the flat side of the belt does slip, then I will remove the pulley and machine the grooves and use the ribbed side of the belt .
One good reason for the poly v belts : poly V or serpentine belts are dirt cheap on ebay .
And, after some thought I am not convinced that the A section belts will track on the flywheel . B section would track Ok , as they are a lot wider in section