🔍 Key Concepts

• Compression rings vs. oil control (scraper) rings – how they differ in location, shape, and purpose • Typical cross‑section shapes of top compression rings (inside bevel, outside bevel, rectangular, keystone, etc.) • How a ring dam or heat dam is usually shown in cross‑section near the top ring land

💭 Think About

• Carefully study the cross‑section of each piston ring in the illustration: Which ones have a rectangular shape, and which (if any) have bevels or special shapes? • Look at the lowest ring on the piston: does it look like an oil control/scraper ring (often slotted or with drain holes) or just another compression ring? • Is there any clear feature between the top ring and the piston crown that could reasonably be called a ring dam or heat dam?

✅ Before You Answer

• Confirm how many rings appear to have oil‑control features (slots, holes, or multiple segments) versus plain compression profiles. • Check whether the top ring cross‑section clearly shows an inside bevel, outside bevel, or no bevel at all. • Verify whether any structure between the top ring groove and the piston crown could function as a heat/ring dam, based strictly on what is drawn.