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Fuel Systems

Carb Class: 3 Circuit Metering Blocks

Carb Class: 3 Circuit Metering Blocks

Shown below is a typical billet metering block from the side that mates to the main body. This particular model does not utilize a power valve or have a place to do so - essentially it is a race only calibration. From this side you can visually locate all of the tuneable orifices including emulsion, idle feed restriction, and intermediate discharge.

  • Idle feed restriction controls the amount of fuel that mixes with air from the idle air bleed decrease orifice size to lean out idle mixture - increase to richen.
  • Intermediate discharge controls the amount of fuel/air mixture that is supplied to the intermediate pull-over tubes located in the main body.
  • Emulsion orifices control how much air (supplied from the high speed air bleed) is allowed to enter the main well of the metering block and ultimately feed the booster venturi.