Who is correct about the cooling of diesel engine exhaust manifolds in highway applications?

In highway applications, it is common for diesel engine exhaust manifolds to not have dedicated cooling systems like those found in some other heavy-duty machinery. Diesel engines generate a significant amount of heat, especially during operation at sustained speeds and loads. However, in highway scenarios, the exhaust manifolds primarily rely on the flow of exhaust gases and the surrounding air for cooling.

Technician B's assertion likely highlights the correct understanding that while exhaust manifolds do undergo heating, they are designed to dissipate heat effectively through their construction and material properties, as well as through airflow. This intrinsic design allows for efficient heat dissipation without the need for additional cooling mechanisms, ensuring the engine operates effectively over long driving durations. Additionally, overheating of the exhaust manifold can lead to premature failure, so proper heat management is crucial, aligning with Technician B's understanding of these components' roles in highway applications.