* Balance: A V8 engine has inherent imbalances due to the reciprocating motion of the pistons. The firing order is optimized to distribute the firing impulses throughout the engine's crankshaft rotation. This evens out the forces, reducing vibrations and improving smoothness. Firing adjacent cylinders in quick succession would create significant shaking.
* Minimizing Stress: The sequence minimizes stress on the crankshaft and connecting rods by strategically spacing the power strokes. A poorly chosen firing order could lead to excessive wear and tear on these components.
* Smoothness: The result of the balanced forces and minimized stress is a smoother running engine. This leads to a more pleasant driving experience and reduces noise.
In short, it's not about some random arrangement. Extensive engineering and testing went into determining the optimal firing order to maximize the small-block V8's performance and longevity. Other V8 engines from different manufacturers will have different firing orders optimized for *their* specific designs.
