1981porsche911SCw/webers

I have a 1981 911 SC 3.0. I have removed the stock CIS fuel injection. I am ready to install weber carbs. But I am not sure exactly how to connect them. The line from the fuel tank seems to run to the pressure accumulator and then to a big fuel fillter. I assume I take the fuel line coming off the fuel filter and split it into two lines running to the two webers? There is a line running from the bottom of the fuel accumulator. Where does that go? Also, I have a adjustable pressure regulator with two fittings, but I can't tell which is in an which is out?
Can anybody give me a little of their wisdom?

Don

DGaunt

You definitely need the pressure regulator to drop the 70 PSI from the pump to about 5 psi for the Webbers. This ***'y is usually mounted on the firewall, centered on the engine bay. The rest is just plumbing.

You might want to have a shop set them up the first time as they can be fussy. You also need a syncrometer to ensure all the butterflys are flowing the same air.

There are lots of conversions around, perhaps you can look at a car in a shop or a track day in your area?

Steve Weiner-Rennsport Systems

Hi Don:

As Dave said, you need to drop the fuel pressure from 70 psi to 3.5 for the carbs. That's a tall request,.... FWIW, I use the Bosch pump (914/6) made specifically for these applications.

The output of the fuel filter gets connected to the input of your FPR (what kind is it?) and the outputs of the FPR feed the carbs. I use a Racor 110A fuel filter/water separator.

I install a 0-15 psi fuel pressure guage in one of the FPR outlets to measure pressure and adjust the regulator to spec.

The extra line from the accumulator get plumbed back to the fuel pump as thats a return line.

Webers want 3.5 psi, and no more. Set your float levels at that spec.