bottom dead center

 

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bottom dead center

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bottom dead center (uncountable)

1. (mechanical) A position in the cycle of a piston engine wherein the piston is at the bottommost point in its stroke. In a four-stroke cycle, BDC occurs twice: at the end of the intake stroke and at the end of the power stroke.

   Synonym: BDC (initialism)

   Antonyms: top dead center, TDC

   Hypernym: dead center

2. (mechanical) The reference mark on a flywheel (and engine block) indicating that the engine is in this position, when aligned.

   Synonym: BDC (initialism)

   Antonyms: top dead center, TDC

   Hypernym: dead center