Standard aircraft cylinder over-sizes usually range from 0.010 inch to 0.030 inch. Oversize on automobile engine cylinders may range up to 0.100 inch. This is because aircraft engine cylinders

Standard aircraft cylinder over-sizes usually range from 0.010 inch to 0.030 inch. Oversize on automobile engine cylinders may range up to 0.100 inch. This is because aircraft engine cylinders

• A. have relatively thin walls and may be nitrided
• B. have relatively thick walls
• C. may be nitrided but not thin-walled
• D. are made of aluminum

Answer: (A)

Thin-walled cylinders save weight in aircraft engines, but that also limits how much material you can remove from the bore without weakening the cylinder. To keep durability in that thin-walled design, the bore surface is often nitrided, giving a hard, wear-resistant layer without adding thickness. That combination—thin walls plus nitriding—restricts how much oversize can be safely accommodated, which is why aircraft cylinders typically have a smaller oversize range (about 0.010 to 0.030 inch). Automobiles use thicker-walled cylinders, so more material can be removed and larger oversizes (up to about 0.100 inch) are feasible, with nitriding less essential for wear life. Thus, the idea that aircraft cylinders are thin-walled and may be nitrided best explains the smaller oversize range.

Thin-walled cylinders save weight in aircraft engines, but that also limits how much material you can remove from the bore without weakening the cylinder. To keep durability in that thin-walled design, the bore surface is often nitrided, giving a hard, wear-resistant layer without adding thickness. That combination—thin walls plus nitriding—restricts how much oversize can be safely accommodated, which is why aircraft cylinders typically have a smaller oversize range (about 0.010 to 0.030 inch). Automobiles use thicker-walled cylinders, so more material can be removed and larger oversizes (up to about 0.100 inch) are feasible, with nitriding less essential for wear life. Thus, the idea that aircraft cylinders are thin-walled and may be nitrided best explains the smaller oversize range.