🔍 Key Concepts

• the purpose of crosshatch patterns on cylinder liners in diesel engines • how piston rings seat against the liner during the break‑in period • the role of liner surface finish in retaining lubricating oil on the cylinder wall

💭 Think About

• Think about what would happen if the liner surface were perfectly smooth—how would that affect ring seating and lubrication? • Consider why manufacturers specify a particular crosshatch angle and roughness—what two main goals are they trying to balance? • Ask yourself whether crosshatching is mainly about mechanical wear-in, lubrication, or both.

✅ Before You Answer

• Verify whether a slightly rough, patterned surface would speed up or slow down the proper wear-in (seating) of the rings. • Check if small grooves or scratches can hold a film of oil between the ring and the liner, and why that matters. • Confirm whether the same surface feature (crosshatch) can serve more than one function at the same time.