In an inline four-cylinder aircraft engine, what is true about the crankshaft?

In an inline four-cylinder aircraft engine, the assertion that allows a firing order of 1-3-4-2 is accurate and significant for the engine's performance. This specific firing order is essential for balancing the engine and achieving smooth power delivery. Each cylinder fires in a sequence that optimizes the engine's operation, helps reduce vibrations, and ensures that power strokes are evenly distributed across the crankshaft's rotation.

This firing order also contributes to how the engine's components, like the crankshaft and camshaft, are designed. The correct sequence helps in minimizing the mechanical stress on the engine and enhances its overall efficiency. It is a well-established order in many inline four-cylinder designs, promoting effective combustion and better performance characteristics.

In contrast, the other options present different characteristics that do not align with how inline four-cylinder engines typically function. The crankshaft does rotate at the same speed as the camshaft, and engine design typically leads to crank throws being placed 180 degrees apart for a four-cylinder layout due to their alternation in firing. Additionally, while modern materials provide some resistance to flex and twisting, all crankshafts experience some degree of stress and deflection under operational conditions.