Originally Posted by JoelWisman
Steveman, I wouldn't rule out ambient temperatures inside the case or of the case itself, nor oil cooling or the lack there of. The magnet wire itself generates a lot of heat. That heat leaves by convection, conduction, and radiation. The warmer the case, oil, and gases are, even though still bellow the maximum temperature the magnet wire insulation can take, the slower the magnet wire can shed heat through the above named dynamics.
No matter the ultimate cause of stator failure, improving any of the things that age stators will increase it's life. No stator lives forever, they will all die, we just want to make them live longer.
Well, ...assuming that BMW will not do anything to help finding an acceptable solution we then should reduce our efforts to find the cause(s) and put even more effort into reducing the stator coils temperature, meaning all following points could (and most likely will) reduce stator temperature, thus extending its life cycle
.) reduce exhaust tubes temperature (heat shield, heat wrap, coating etc.)
.) reduce engine temperature (different thermostat, bigger waterpump rotor, free airflow to radiator)
.) use different regulator (compu-fire may work)
.) use stator from Camro or other brand or rework existing one
.) reduce maximum alternator power
.) improve contact surface between stator coil and engine cover
anything else? By the way has anyone done the regulator mod?