Why do aircraft engine cylinders typically have a smaller oversize range compared to automobile engine cylinders?

The correct answer focuses on the construction and material characteristics of aircraft engine cylinders compared to those of automobile engines. Aircraft engine cylinders typically have relatively thin walls to save weight, which is a critical factor in aviation. This design allows for greater performance but also means that there is less material available for wear and erosion that occurs over time.

The process of nitriding, which is a heat treatment that diffuses nitrogen into the surface of steel, enhances surface hardness and wear resistance. Aircraft engines often undergo this treatment to improve durability and longevity, which is essential given the high stakes of aviation safety. The thinner walls combined with the nitriding process result in a more limited oversize range because any significant wear or oversizing can compromise the structural integrity of the cylinder.

Therefore, the specific material considerations and the engineering decisions made to optimize weight and performance in aircraft engines lead to a smaller permissible oversize compared to automobile engine cylinders, which do not typically face the same stringent requirements in terms of weight and operational safety.