FAA Powerplant Written Practice Test

Which component is NOT part of the reciprocating engine cooling system?

1. Radiator

2. Cylinder fins

3. Engine cowling

4. Cylinder baffles

The correct answer is: Radiator

The correct choice indicates that the radiator is not a component of the reciprocating engine cooling system. In reciprocating engines, cooling is primarily achieved through air or liquid, and while radiators are integral to liquid-cooled engines, they are not typically used in the cooling of reciprocating aircraft engines, which often rely on airflow to manage temperature. In reciprocating engines, components like cylinder fins, engine cowling, and cylinder baffles all play crucial roles. Cylinder fins increase the surface area for heat dissipation, allowing more effective cooling through airflow. Engine cowling also aids in streamlining airflow over the engine to enhance cooling efficiency. Cylinder baffles further direct the airflow to ensure that it passes over the cylinders effectively, preventing hotspots and helping maintain optimal operating temperatures. Thus, the use of a radiator is characteristic of liquid-cooled systems, while reciprocating engines commonly utilize the other components mentioned for effective cooling.