Inspired by a discussion in chat.
Most GA piston singles are powered by either Lycoming or Continental engines.
The engine designs used by both manufacturers are broadly similar (4-cycle, horizontally-opposed, gasoline-powered, air-cooled), and they're both generally available with either carburetors or fuel injection, but I know they're not "identical products".
What are some of the differences between the designs used by the two manufacturers, and what practical implications do those choices have for pilots?