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Harley motors are designed to be loud. They are called "thumpers" because both pistons are at top dead center at the same time, therefore they both fire at the
by ficklepickle 9y ago
Harley motors are designed to be loud. They are called "thumpers" because both pistons are at top dead center at the same time, therefore they both fire at the same time. This also causes massive vibration. Very inefficient and lame IMO.
- qbrass 9y agoThey don't. It's a 45 degree vee with a common crank pin. The front cylinder fires, the crank rotates 315 degrees before the rear cylinder fires, then the crank rotates 405 degrees before the first cylinder fires again. The 90 degree difference between firing pulses is what makes the engine shake and sound the way it does.