“BLAP!BLAP!BLAP!BLAP!”
The cow goes “Moooo.”
Gotta go.
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Cecil’s column can be found on-line at this link:
Did Harley-Davidson patent the sound of its motorcycles? … (15-Sep-2000)
moderator, «Comments on Cecil’s Columns»
For those who don’t already know, there’s a reason why the Harley-Davidson V-twin sounds the way it does. The column’s assertion that all big bikes sound the same, by the way, is nonsense. Only sequentially firing four-stroke v-twins sound that way.
Here’s the deal. A cylinder in a four-stroke engine goes through four phases.
- Piston goes down, fuel/air mixture comes in through the open intake valve.
- Piston comes up, compressing the fuel and air.
- Spark plug sets the fuel afire. The burning fuel expands, pushing the piston down.
- Piston comes up, pushing burned fuel (“smoke”) out the open exhaust valve.
In a Harley, the two cylinders are spaced apart in a vee (54 degrees? 57?) The cylinders share a single crank pin, and they have their firing phases one right after another. So, the engine goes Ba-bump, then goes through two complete revolutions before another Ba-bump. That’s where the syncopated beat comes from. In a vertical (side-by-side) twin, the power strokes are evenly spaced, bump, bump, bump, bump. In a four-cylinder bike, the exhaust pulses are so frequent and evenly spaced that the noise is a continuous howl.
I hope I clarified things a little.
Please note, Asknott, that the column does NOT say that all motorcycles sound the same. The column says that arument was made by the Japanese motorcycle companies who were suing to overturn the Harley trademark.