🔍 Key Concepts

• normal appearance of compression ring sealing surfaces in a healthy diesel engine • effect of gas blow-by on ring and liner surfaces • how lubrication patterns show up visually on rings and cylinder walls

💭 Think About

• Think about what happens to the ring’s sealing face if hot combustion gases leak past it repeatedly—how would that affect color and texture? • If lubrication were excessive or insufficient, what kind of deposits, discoloration, or wear marks would you expect to see, instead of a bright shiny metal face? • When rings are doing their job correctly, how do they contact the cylinder wall, and what kind of wear pattern does that usually create on the sealing surface?

✅ Before You Answer

• Compare the terms bright and shiny versus burned, pitted, or carbon-coated in your mind when evaluating the options. • Ask yourself which option would most likely produce abnormal wear or damage rather than a clean, polished surface. • Verify which condition would leave the ring face looking polished by normal sliding contact instead of eroded or fouled.