Have always been curious... is the glass bowl suppose to be full or half full... dont know that the rpm fluctuations are a fuel supply issue or not, but still wonder about that glass fuel filter bowl... what say you, full or half full?

Cheers.. Brian

Cylinder Index = 84

Current Experiment = `57 Tbird, Grand Rapids, Michigan

In my 56 TBird, if I remember correctly, the bowl runs about 1/2 full. Of course, I can't tell when I'm doing 65 MPH.

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

In my F100 the bowl is full at idle.

Warsaw, IN

I also ponder the fuel bowl question on my '54 239 car. At times it is either full, half full, or as low as 1/4 full. The engine never seems to starve for fuel.This is my theory at the moment (always subject to change) that when the fuel requirement is high, (carb needle valve open) the pump is working and will fill the bowl up. When the pump catches up with demand and the needle valve closes, the glass bowl level will stay wherever it happens to be at that time.

Now, after I wrote that it makes way less sense to me, but I think I will go ahead and post it anyway for the sake of discussion. It looks like if this were true, the bowl would be full all or most of the time, and this just isn't the case. Methinks I was having a Homer Simpson moment. LOL I hope someone can explain this. "DUH"



Tom from the chiggerfarm located in the beautiful Heart of Central Texas

When you cannot dazzle others with your brilliance, baffle them with bullcorn!

Air (or fuel vapor) is trapped in the bowl of the filter. It changes according to pressure (as you have already pointed out). If you look the outlet of the filter is lower than the top of the filter which prevents it from bleeding the air out. If you could bleed the air out it would stay full but the fuel would eventually vaporize enough for the "air" to return.

I agree that the whole purpose of the glass filter is to see the quality and quality of the fuel going through. Not Trapped air

Grizzly (Aussie Mainline)