What gives V-twin motorcycle engines their unique sound?

Question

V-twin motorcycles go pbbbbbbbt (and have lower RPM) while higher V motorcycles go vroom just like cars.

In: 3

Answer 1

Every time an exhaust valve opens in a cylinder, the residual pressure of the exhaust gases is suddenly expelled thorugh the exhaust, causing a loud “pop”. In most engines, the pops are regularly spaced, creating a regular “tone”. In the V arrangement, two pops happen close after one another, and then there’s a longer delay before the next two. This causes the characteristic noise.