What is the difference in these discharge nozzles?

[Paul G]

What are the performance differences in these different style squirters?


AED calls these straight


Holley calls these "tube type"


Holley calls these "anti pullover"

[c00nhunterjoe]

Not much difference in my opinion, especially on a street car. But given those options, i prefer the tube style because it directs the spray a touch closer to the blades for atomozation purposes. But that is still just my opinion as i have seen no difference in them.

[Paul G]

Do you mean the ones Holley calls tube style? Or the AED ones that actually have little tubes?

[c00nhunterjoe]

The aed pictured ones with the brass tubes.

[XH29N0G]

I haven't inspected them much in operation, but I have both of the top two types and have not notice anything obvious in how they operate.  I assume if I spent a long time looking and filming them in operation that I would see a difference, but so far I have not see it.  I will be interested to see if someone has done a test and can explain how they operate differently and one is better than another in a given situation. My guess is that the size of the nozzle matters a whole lot more than the difference in their ability to aim.  BUT I could be completely wrong, too.

[c00nhunterjoe]

The reality is any design will work as long as it is the correct shot size for your application. The style is personal preference in my opinion.

[Bronzedodge]

The anti-pullover design is usually used in Holley 4165 series carburetors that have lightweight check valves under the pump nozzles.  If the accelerator pump discharge check needle or ball is missing, fuel can be siphoned out of the standard nozzles by airflow past the nozzles at higher rpm.

[BSB67]

They all have check valves/balls.  But you are correct in their function.  The antipull over is better suited for the stronger "pullover" signal from the 4165/4175 carbs.