I think these are the knuckles, acording to the guys who run the F103's at my track these are almost unbreakable,
http://www.burienrcracing.com/f1whitfronup.html
that cooling idea sounds good, but my 27t monster does not even get barely warm after running for 10mins,
what motors do you run? I suppose with oval racing the motors are going at 100% all the time?