Fuel supply for webers and FE

67FEfastback · #1 (**permalink**) 12-04-2009, 03:44 PM

What are the fuel tank to engine requirements for a weber set up (434 FE). Is there a return line required?

Gunner · #2 (**permalink**) 12-04-2009, 04:45 PM

Typically only FI systems and high-volume electric fuel pumps need return lines. Webers are just carbs, so unless you're running something unusual, 3/8 fuel line and -6AN hose and fittings all the way should be fine.

Webers don't typically take any more fuel than a dual 4BBL (or a single, for that matter)... it's just divided up among more individual metering units.

*13* · #3 (**permalink**) 12-04-2009, 05:54 PM

I'm running a mechanical fuel pump with a pressure regulator set at about 3psi. to my carbs

undy · #4 (**permalink**) 12-05-2009, 05:22 AM

I would not own a car without a return fuel line, carb (Weber/Holley etc) or otherwise. It's much easier to maintain correct fuel line pressures that way. Quite a few people that like to blame difficulties with hot start and heat soak problems actually have excessive fuel pressure problems that could be corrected by a return line and return style fuel regulator.

Dave

Wolfzter · #5 (**permalink**) 12-07-2009, 04:24 PM

Totally agree with UNDY...return line! I am experiencing some plug fouling problems with the terminal Weber Carb which I now believe is due to fuel pressure accumulation. Also, mind your fuel pressure at 3.5 to 4 pounds...small increments in pressure result in totally different engine behaviour. It can get a little frustrating...

*13* · #6 (**permalink**) 12-07-2009, 04:39 PM

Concerning heat, I could use a return line though I did solve that partially by cutting slots in the uprights for my fuel log.
I reset my fuel pressure from about 3.25 lbs down to about 3lbs & didn't notice any differences in attitude. Did it more to see what happens. Fuel pressure seems fine to me. I haven't had any problems related to that, personally.

RodKnock · #7 (**permalink**) 12-10-2009, 02:42 PM

I'm considering Webers too, at some point, maybe, but I heard through the Weber grapevine

that there are guys out there who had the return line to the Webers hooked up, had some issues, and then decided to disconnect the return line. Without the return line, their cars are running, as Jamo would say, muy goodo.

*13* · #8 (**permalink**) 12-10-2009, 03:02 PM

Only problem I've experienced was heat, in my current setup. As mentioned I found a remedy. Running fuel lines around the carbs is a solution for this also but just doesn't look as cool for us SB guys.

rokndad · #9 (**permalink**) 12-10-2009, 05:17 PM

Quote:

Originally Posted by RodKnock

I'm considering Webers too, at some point, maybe, but I heard through the Weber grapevine

that there are guys out there who had the return line to the Webers hooked up, had some issues, and then decided to disconnect the return line. Without the return line, their cars are running, as Jamo would say, muy goodo.

I'm one of the guilty parties. My engine seemed to stumble like fuel starvation at around 5000 rpm, and I was messing with e-tubes and float levels to fix it. Then it hit me, sounded like fuel starvation (have the proper regulator and inline gage set at just over 3 psi). So I plugged the output to the return line and capped the other end going back to the tank.

NEW CAR!! No more stumble, and a full on screamer very smoothly right on up to 6500 rpm and way too fast in second gear on a long freeway on ramp. Blew right by the traffic on the freeway. Not going to do that again.

That was a couple of months ago, and I'm still waiting to heal up and do a little more tweaking to the idle jet holder. Phil (priobe) knows what I'm talking about. Always several schools of thought on these subjects and what's right for one may not suit another. No return line is the way I'm going to roll.

Gunner · #10 (**permalink**) 12-10-2009, 06:28 PM

I've never seen a need for a return line at street fuel pressures. For EFI or drag/race pressures (7-10 psi or more), sure, it's a way to keep the fuel supply stable and ease the load on a fuel pump. But for a 3-4 psi street pump? Nahhhh. It's just mechanical bling, IMVHO.

RodKnock · #11 (**permalink**) 12-10-2009, 07:14 PM

Quote:

Originally Posted by rokndad

I'm one of the guilty parties. My engine seemed to stumble like fuel starvation at around 5000 rpm, and I was messing with e-tubes and float levels to fix it. Then it hit me, sounded like fuel starvation (have the proper regulator and inline gage set at just over 3 psi). So I plugged the output to the return line and capped the other end going back to the tank.

NEW CAR!! No more stumble, and a full on screamer very smoothly right on up to 6500 rpm and way too fast in second gear on a long freeway on ramp. Blew right by the traffic on the freeway. Not going to do that again.

That was a couple of months ago, and I'm still waiting to heal up and do a little more tweaking to the idle jet holder. Phil (priobe) knows what I'm talking about. Always several schools of thought on these subjects and what's right for one may not suit another. No return line is the way I'm going to roll.

OK, my Weber source has outed himself.

67FEfastback · #12 (**permalink**) 12-19-2009, 02:09 PM

Does anyone have some pictorial examples of how one would add a fuel return line to a stock type sheet metal gas tank?