in the 50-Year-Old Conventional Design.
Stock Holley discharge nozzles are very close to the throttle plates. This creates a fuel-distribution problem at part throttle. Throttle plates direct fuel to the center of the intake manifold. This richens center cylinders and leans end cylinders, even if the total mixture was perfect. This reduces potential torque and smoothness (Figure 1).
The new C&S design fixes this problem. Location of the fuel delivery nozzle is raised one-half inch, allowing the mixture to spread before reaching the throttle plates. A greater distribution improvement is gained with a new nozzle design.
The C&S nozzle is machined, not cast; does not "go rich" at high RPM; and has only one-fourth as much fuel-delivery variation from low to high vacuum. It is called an aerosol nozzle because it works on the same principle as an aerosol spray can. As high-velocity air passes over the square-cut tube end, energy is transferred to the liquid, which is broken up into a very fine mist. A portion of fuel travels back the tube to be fogged off at the venturi lip to deliver highly vaporized fuel to the lean side of the throttle plates as shown in Figure 2.
The result is a dramatic increase in torque at part throttle and a feel of smoothness. Top end power is increased due to better vaporization, less variation in air/fuel and higher air velocity through the venturi.