Ah yes, you're using the 1717, not a 15xx. Hmm, tricky one. Whenever I think of motor cooling I always keep looking at
this. Completely daft and impractical, but big blowers just look epic. In your case, maybe a homebrew blower shroud is in order- all it is basically is a tube with the bottom 1/3 removed, and a square hole in the top for the fan to mount over/into. So long as its a tight fit around the motor ( pvc, or maybe even copper tube? ) the air has no choice but to be forced down around the motor through the fins, just like the normal blower, then add some details perhaps to make it look a bit nicer....