Fuel leak question

[priobe]

I dont recall my pump jets ever leaking. I have tried shutting down my pump to lower the level a block before shutdown. It still leaks

The only thing in my situation that changed was new pump jets( which I replaced back to the old) and float level (which I lowered before shutdown.

The carb bodies themself are cool to the touch.

Zimmy,

Has your system always leaked?

Eljaro,

Has your system always leaked?

I dont recall other complaining about the leaking from the pump jets.

Rick,
I am not saying you are not correct but it seems something changed to cause the pump jets to start leaking. Or I never noticed it.

One thing, if you block the by pass all hell breaks loose through the pump jets.

Maybe its the fuel?

Just when I think I am moving forwad with these carbs I go 1 step back.

[carmine]

A zero bypass valve will most defanetly biuld up fuel pressure in the pump chamber caused buy heating up of the carb body and expanding the fuel which has no place to escape except out the pump jets.

The larger the bypass valve # the more of the pressure biuld up will divert back to the main float chamber, Thus allowing less fuel out the pump jets during pressure build up from shut down heat sink of carb body.

Yes your carb body will be cool to the touch after shut down.
Check how hot they are 10 minutes later.

The pump Jets are not affected by the angle the carbs are on because they are fed by an inlet located at the bottom of the main float chamber.

[priobe]

Originally Posted by carmine

The pump Jets are not affected by the angle the carbs are on because they are fed by an inlet located at the bottom of the main float chamber.

Is there anyone that has a 10 degree intake that does not leak.

"This thing is driving me nuts!!! I dont ever remember mine leaking"

[carmine]

I think they always leaked and you never noticed it.
More so now that you have a #0 bypass valve.

[Eljaro]

My Webers have always leaked and are one of my main concerns right now.
The pump bypass does not help, I tried that out with the smallest one possible (0.35) and only got a bog when accelerating. The phenolic spacers helped some but did not totally do away with the problem.
When I stop the car the Webers are cool. After a while they get really hot from the engine heat. They get so hot that the fuel trapped in the conduit between the pump plunger and the pump jet starts boiling (you can hear it !) and drips out of the pump jet. And it can be quite an amount.
The float level has no effect on this because the pump circuit gets the gasoline from the bottom of the bowl as has been said here, and if you lower it too much you can get fuel starvation when taking fast and tight turns. This problem has nothing to do with the fuel level and fuel supply by means of a bypass, lowering fuel pressure or letting the fuel bowls empty some before shutdown.
The only way to get around this problem is to get the hot air out of the upper engine bay.
Maybe a flexible duct drawing air between the Webers and with an exhaust fan infront of the engine or behind it or a 12 Volt computer fan behind each side vent in the engine compartment and have them come on when you shut down the engine. This way you remove the hot air that is trapped under the hood.
The aluminum Webers heat up fast with the hot air trapped under the hood and slowly exiting through the scoop.
This can be done elegantly with a relay and a timing circuit so the fans come on automatically and shut off after 10 minutes.
What I do now and what really helps is to open the hood when I stop and the heat gets out fast and does not soak up the Webers. No dripping this way.