[Jack Gifford]

One observation of these posts- there are some references to pressure on the fuel in the float chamber. I've never seen a carb without a vent to atmosphere from the the float chamber.

I may be missing the point of having a return-to-tank line from between the pump and carb. It sounds to me like a crutch for a failing float system (or too high a pump pressure). ???

[3X24SPD]

Originally Posted by Jack Gifford

One observation of these posts- there are some references to pressure on the fuel in the float chamber. I've never seen a carb without a vent to atmosphere from the the float chamber.

I may be missing the point of having a return-to-tank line from between the pump and carb. It sounds to me like a crutch for a failing float system (or too high a pump pressure). ???

Hi Jack,
You are absolutely correct. Thanks for pointing that out.
There is and should be no pressure in the float bowl- it is vented to atmosphere.
My response was poorly worded. Sorry about that.
The accelerator pump obviously requires a one way check valve- refilling from the float bowl- which in my case was the cause of the float bowl emptying- through the accelerator pump discharge nozzle.
The Shield I installed reflected the source of that thermal and its effect on the constraints of the accelerator pump volume.

[Sirrotica]

Years ago I figured out a way to find out if the suction side of the fuel system was drawing in air while running. You just put your fingers over the bowl vents on the carb while the car is idling, and it would immediately flood the carb. This doesn't pinpoint where the problem is, but it is a quick tool to find out if all the connections should be scrutinized for suction leakage. I sometimes used this to trouble shoot a fuel starvation problem.

I've found over the years if there is no air intrusion the car will continue to run the same as if the bowl vents were uncovered. It worked well over the years for me.