« Back to Dictionary Index

Before Bottom Dead Center (BBDC)

  1. Definition: BBDC refers to a specific position of the piston in an engine’s cylinder as it moves downward in its stroke.
  2. Position: It occurs just before the piston reaches the lowest point in its travel, known as Bottom Dead Center (BDC).
  3. Significance: This position is important in the context of engine timing and operation.
  4. Usage:
  • In the combustion process, various events such as fuel injection, ignition, or valve timing may be referenced to positions like BBDC.
  • For instance, fuel injection in a diesel engine might start slightly BBDC to ensure optimal combustion and power generation.
  1. Application: Understanding and accurately identifying BBDC is crucial for engine tuning, performance optimization, and maintenance.
  2. Measurement: BBDC is typically measured in degrees of crankshaft rotation before the piston reaches BDC.
« Back to Dictionary Index