Circle Track / Road Race Holley HP 4BBL Mechanical Secondary 1000CFM Stage 4 – 80513





  • 1-3/4″ Throttle Bore
  • Choose best metering block design to match your engine specifications, and class rules if applicable.
  • Booster design is chosen based on your engine specifications, then balanced and modified for increased signal strength and atomization characteristics, providing crisper throttle response and driveability, as well as increased HP and TQ thru-out the rpm
  • Assembled with reusable gaskets for ease in tuning and service
  • All idle and off-idle functions modified for long duration, low vacuum camshafts.
  • All fuel circuits, air bleeds, and calibration components engineered to match specifications of YOUR engine to provide maximum possible HP&TQ; as well as response and consistency.
  • All circuits will be modified and tuned to match the specifications of your engine combination, Including:
  • All components are then vibratory tumble polished and dichromate coated for a brilliant high gloss gold finish
  • All body surfaces machined for maximum gasket sealing, ensuring consistency and reliability
  • Floats are modified based on applications, drag float, single taper, double taper
  • Metering block design is selected based on your engine combination
  • High flow .130″ needle and seat assembly.
  • Venturi size is increased to provided maximum airflow capacity to match the needs of your engine to produce maximum possible torque and horsepower. All casting flaws are removed and venturis are finely polished to eliminate power-robbing turbulence
  • Upper venturi enlarged to maximum possible size to create dramatic increase in peak airflow capacity
  • Select only the highest flowing castings
  • Removable air bleeds installed in main body
  • Metering blocks are hand selected and all circuits and passages are checked for casting flaws and obstructions, as well as proper sizing
  • 1 YR warranty all parts and labor
  • Balance all metering passages, then resize and modify for optimum fuel curve, including:
  • Emulsion, High Speed Air Bleed, Idle, Idle Air Bleed, Main Well, Main Well Exit, Power Valve, Transition

Additional information

Weight 15 lbs
Dimensions 15 × 15 × 15 in


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