I remember the info on the Al-Beryllium. The issue was that they were using the material for the rings/pistons/ and rods. The material reduces friction, was lighter, and had a higher G load capability.
The lighter and G load is significant since it would allow the engine to rev higher adn the con rods not break from the extreame G loads, something like 10,000 G's at 20K RPM.
It was demed unsafe since the high temp would cause Beryllium particles in the exahust and expose everyone at the track to potentially unsafe toxic substances.
Reallity is more like, MAX and Bernie trying to keep the cars from going to FAST is probably what killed its use. They are off trying to figure out how to SLOW the cars down again.
