What technique is typically utilized to measure the travel of a piston during its stroke?

The method commonly used to measure the travel of a piston during its stroke is the dial indicator. This tool provides precise measurements of the linear movement of the piston through a calibrated scale, allowing for accurate assessment of stroke length and any variations over time. The dial indicator is advantageous because it has a small contact tip that can easily be placed against the piston or the top of the cylinder, providing a direct reading of the displacement.

In contrast, while other tools like timing disks, caliper gauges, and torque wrenches have specific uses, they are not designed for measuring piston travel. A timing disk is more suited for timing events regarding valve opening and closing, indicating its use in synchronizing engine timing rather than piston movement. Caliper gauges measure external dimensions and might be used for various tasks but lack the ability to measure stroke travel directly. Torque wrenches are designed for applying a specific torque to fasteners and do not serve the purpose of measuring linear movement at all. Therefore, the dial indicator is the most appropriate and effective tool for this particular measurement in the context of engine mechanics.