3 Circuit Metering Block Information
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.