Speedpassion seem to melt when they get hot so i wouldnt have one them,
LRP are rapid get hot and dont mind (had mine at 113deg C every race of a 2 day national) and not a probs but the magnet goes soft very quickly and loose performance.
Have you looked at GM motors?
Chris Grainger 5/6 time national champ runs them and his car is always the fastest in a stright line and they dont seem to get mega hot and melt.
Thats where i would start
