quote:Originally posted by accobra:
But I think on the webers ... correct me if I'm wrong ... some fuel seems to leak past the needed valve and seat and flood the motor ?
Ron
Yes, you are correct BUT JUST with the stock needle and seat. With the Gene Berg glass ball needle and seat, no. They will hold I'm told 20 psi.
What happens with the Webbers is that when the engine is running it will hold 3.5 psi. When you shut the engine off, the pressure will rise to 4.5 psi. At least that's the highest that I have seen.
That seems to be what the issue is with the stock needle and seat. It can't hold that pressure and the carbs overflow.
In that situation, they seem to peculate the fuel like a coffee pot on a stove.
The pressure regulators seem to have a +/- of at least 1 psi. They all use a spring loaded diaphram as far as I know.
Even on the EFI engines I have here the pressure varies according to the pressure gauge. On the FI cars my pressure varies 10 psi or +/- 5 psi.
What is effecting that I think is the variation of the bi-pass valve that returns fuel to the tank.
This guy is using a return line to the tank from the Webers and the pressure regulators is at the end of the carbs before the return to the tank.
http://www.timsroadster.com/html/tuning_webers.html
He has 5,000 miles on the setup and it hasn't self destructed yet but it defies logic of my thinking. Good thing I don't need to make a living doing plumbing and risking my reputation on it?
