The term's been used to describe high-displacement iron block engines, exemplified by those in mid-20th century american muscle cars. They produce lots of noise

The term's been used to describe high-displacement iron block engines, exemplified by those in mid-20th century american muscle cars. They produce lots of noise and torque, and aren't very fuel efficient. Like a mainframe. The other sort of big iron makes a lot of heat and flattens out big wrinkles, and ruins delicate fabrics-- also like a mainframe.