What does the wrist pin do in an engine?

The wrist pin serves a crucial function in the engine by connecting the piston to the connecting rod. This pin allows the piston to pivot as it moves up and down in the cylinder during the power cycle. When the engine operates, the connecting rod translates the linear motion of the piston into rotational motion, which ultimately drives the crankshaft. This relationship is essential for converting the energy produced by combustion into mechanical power.

Without the wrist pin, the direct connection between the piston and the connecting rod would be compromised, leading to inefficiencies in motion transfer and possible engine failure. The other choices pertain to different components and functions within the engine, such as securing the crankshaft, sealing the combustion chamber, or managing oil flow, but do not relate to the specific role of the wrist pin.