Final answer:
The clearance between piston rings and the ring lands is measured with a feeler gauge, which helps ensure the engine operates within its correct specifications.
Step-by-step explanation:
The clearance between the piston rings and the ring lands is measured with a feeler gauge. This tool is designed to slide into the gap to measure the space between components accurately. In the context of an engine, the clearance is crucial for allowing the piston rings to expand due to heat without seizing against the ring lands. Insufficient clearance can cause engine damage, while too much clearance can lead to decreased engine performance and increased oil consumption.
A feeler gauge consists of a series of metal blades or wires of different thicknesses marked with their size. To measure the clearance, you select the appropriate blade thickness that fits snugly without forcing it into the gap. It's important for engineers or mechanics to ensure that the clearance meets the specifications outlined for the engine to maintain its proper function.