rc-zombies: Thanks for the info on drilling, I was worried about delamination.
Hope to give it a try on the weekend.
What sort of fans are people using? CPU fans? Or something else? Whatever computer fan will fit? is 12v ok? Has anyone tried also fitting one of those cone shaped things over the side of the motor to duct air in? I was thinking you could probably make one out of the top of a coke bottle?