What happens to oval shaped pistons as they heat up during operation?

As oval shaped pistons heat up during operation, they expand to a round shape due to thermal expansion. When metals are heated, their molecules move more rapidly, causing them to occupy more space. This characteristic is an essential property of materials, including those used in engine components.

Pistons in engines need to fit snugly within the cylinder to maintain compression and efficiency. An oval shape can allow for a better fit when cold, but as the engine heats up during operation, the expansion leads the oval shape to transform more towards a circular shape. This transition helps to optimize the performance of the engine at operating temperatures, enabling smoother movement within the cylinder and reducing wear. The transition also addresses potential issues related to uneven wear or inefficiencies that could arise from an improperly fitting piston as the temperature changes.