[Amps] re cooling of coils

[CLIVE COLLINS]

This may seem to be a bit way out for this field of engineering but there might be some mileage in considering the method.
Norton Motorcycle company produced a very fast racing machine in the fifties and sixties (The Manxman 500) and had problems with the heat generated distorting the exhaust valve stems.
Their answer after a lot of research was to make the exhaust valve stem hollow and fill it with Sodium with significantly good results.
As I am not a metallurgist, I dont begin to undestand the theory, all I know is from experience, it worked.  I wonder if a similar arrangement might be applied to the coil cooling discussion that is presently featuring on this reflector.
Regards,
 
Clive GW3WEQ