A car engine houses a hot and violent interior, with pistons moving extremely fast up and down to power the vehicle down the road. The rings that surround the pistons have the most difficult job of all.
The piston rings execute an important position within the engine: By staying sealed, they direct oil consumption, retain the vacuum within the chamber and keep the walls of the cylinders oiled while keeping the pistons within a tolerable temperature range.
If you install a piston ring upside down, the ring will not be able to make the correct seal. Engine damage can result, as well as diminished engine performance due to the lack of a vacuum within the chamber.
Piston rings can differ in material, depending on the type of engine. Typical passenger vehicles, normally use cast iron. The website Engine Builder recommends steel rings for higher-end, supercharged engines generating a great deal of heat.
