Sound is an important part of the internal-combustion-engine experience, and many engine configurations have their own distinctive sound.
There are many reasons why, but one of the most important factors in an engine’s sound is how evenly the exhaust pulses reach the tailpipes. Evenly spaced exhaust pulses tend to result in higher-pitched, smoother sound. Unevenly spaced pulses in deeper, more complex, and angrier noise.
In this episode, nerdy automotive journalist Jason Cammisa gives an oversimplified overview of the science behind this, explaining how the regularity can be determined by the crankshaft or the exhaust — and giving examples of each.
He covers 4-cylinders (the Honda S2000’s equal-length headers compared to the Subaru WRX STI’s burble), V6 engines (the Nissan VQ versus Ford EcoBoost), V8 (the Ferrari flat-plane crank V-8 versus an American cross-plane V8), V10 engines (the Lamborghini Gallardo even-fire V10 versus the LP560’s odd-fire, which sounds like two 5-cylinders), and the Mercedes-Benz V12 with equal-length headers versus the factory exhaust.