Which component of the piston expands more during operation?

The piston head expands more during operation because it is subject to the highest temperatures and pressure within the combustion chamber. The design of the piston typically allows the head to absorb heat from the combustion process, causing it to expand significantly. This expansion is crucial for maintaining the seal against the cylinder wall, which helps in maintaining compression and optimizing engine performance.

While the piston skirt and piston rings do experience some expansion, their primary functions relate to control and sealing rather than heat absorption. The piston pin, which connects the piston to the connecting rod, has a different role and is less affected by direct combustion heat. Therefore, the piston head's greater exposure to high temperatures during operation leads to its more substantial expansion compared to the other components.