🔍 Key Concepts

• Compression rings vs. oil control rings and their different purposes • How combustion gas pressure is sealed above the piston • How heat is transferred away from the piston during operation

💭 Think About

• Ask yourself: Which component on a piston is mainly responsible for sealing high‑pressure combustion gases so they don’t blow by into the crankcase? • Think about which rings are located closest to the top of the piston and what conditions (pressure, temperature) they are exposed to. • Consider: Do compression rings primarily deal with oil control, heat transfer, or gas sealing? Which is their main design purpose?

✅ Before You Answer

• Identify which rings at the top of the piston are called compression rings, and which lower rings are oil control or scraper rings. • Confirm which function is most critical for engine efficiency: preventing blow‑by of combustion gases, controlling oil, or protecting ring grooves. • Eliminate any option that describes a function usually associated with oil rings rather than compression rings.