this is on my A. this is on a modifided model a speedster. the gas tank is rear mounted but is higher than carb. i installed a modern see thu inline gas filter. I noticed that eventho the gas tank is higher than carb, the filter never gets more than half full of fuel. just barely to the level of the filters outlet. several times the engine acts breifly like it starves for gas.
I'm thinking that with the needle seated or barely open in the needle seat (while car is running), trapped air in the line prevents fuel from filling the filter/line full.
answer, would it help to put a "T" fitting in the gas line between the filter and the carb, run a copper line up and higher than the tank in order to allow air in the line to excape. allowing the filter to fill completely?
It's common for the filter to run less that full at low flow conditions, even on cars with fuel pumps. I have seen it on many 60's show cars and muscle cars.
As far as the engine acting like it's starving for gas, the consensus I've observed on the forum is that it is a bad idea to run an inline filter on a gravity feed system.
Well, if you must you can get in-line filters made for gravity systems from a lawn mower repair shop. They carry a clear plastic in-line filter that fits nicely on the T fuel line. You might have to hook up to the tank and hold the filter open end up to bleed the air out if you want to as I don't think it'll fill entirely on it's own.
PS: I would jump out the existing filter first to see if it affects your starving for fuel condition. If it does you have 2 options. Leave it jumped out or try a gravity system fuel filter.
the model A carb jets are pron to plugging by crap in the gas. i was hoping to avoid that in issue.
This suggestion is totally the product of things I have read on this Forum over the years.
It sounds like the most moronic thing a person could do, but apparently it isn't.
The idea is to close the vent hole in your fuel tank cap, then bleed a little exhaust gas off the muffler or pipe, and feed it into the fuel tank, thereby pressurizing the tank to a low pressure.
I know - on the surface you'd think only a first degree moron would do such a thing. But on reflection, I can see where it isn't as dangerous as it sounds. The exhaust gases getting to the tank are probably cooled way below ignition temperature by the time they get there, and anyway there isn't air in the tank - only fuel fumes, and pure fuel without oxygen can't burn.
I would think adding such a contraption would make for an interesting talking point at shows and meets, in addition to probably solving your problem.
But, don't take it from me. Get the advice of folks who have done it - plenty of whom are regulars on this Forum.
Buy or make something like this.
If there is crud in the tank, it just picks up fuel from somewhere above it. Works great. Doesn't matter how much crud is in there, either. If it passes through this thing, it will pass through a jet.
I've made similar things for small outboard boat engines with gravity flow tanks. I got the brass screen from McMaster Carr.