I have seen some F1 drivers hit the wall just right to knock the endbell off.
Don't remember that happening to me but it has happened.
Would agree 170-180 deg as the upper limit of the motors. Although they start to smell funny around this point. I usually get mine to come off around 125 - 140 deg in sedan. Last month at Memphis the outside temp was 103 deg, at that point, I did not care to check motor temp...
