return and supply fuel lines for Weber 45s

[Hans]

Good point. I was merely commentin on steel line reference.

[Son of Marty]

With a set of dcoes you would need to take a vacuum feed from all 4 manifold runners and run them through a common vacuum chamber to get anything close to a steady signal to the return valve. Also don't forget to provide some sort of safety shut off of the pump incase of accident.

[Chris_B]

I am wondering whether anyone has ever done this.

[Regerfab]

As an alternative to fighting with the steel lines, the copper nickel lines are rated for fuel use and are much easier to work with.

[mgben]

+1 on copper nickel line. My 73 return line was rusted by the drivers footwell.  

Any insight on original plastic line being ethanol compatible? I am about to install carpeting and don't want to have to run new plastic. 

This discussion is making me want to run a second line for feed and ditch the original plastic in the cabin like @M2M3

I would not go stainless braided the whole length of the car, no matter how good the hose is, it is a liability and would need more clamps to stay in place.  (let alone possible bad Chinese hose, new braided hoses for my british cars began leaking after a few years due to ethanol).  

Side note:

Pretty sure Tii's feed from the metal line and return through the cabin and carb cars do the opposite. 

 

[John76]

15 hours ago, Son of Marty said:

With a set of dcoes you would need to take a vacuum feed from all 4 manifold runners

Or...just not use a vacuum return valve.

Use a "fixed" orifice return such as the Jeep filter. Select the size of the return orifice. Most common is 0.60".

[John76]

Sorry...0.060".

[Son of Marty]

Yes that would work, there might be a by pass pressure regulator too, I'm not aware of one, but I haven't looked.

[goodhobbes]

'"M2M3"  Posted on Oct 25th that there is a fuel line (metal) that runs along the drivers side under the car .  I checked and my 1974 model has this line......What is it's purpose?  (I have removed the plastic lines that ran through the interior of the car). Certainly tempted to use it if it has no other significant purpose. 

 

[Son of Marty]

That is the fuel return line, if you plan on using it for supply be sure to flush it out and check for leaks along the whole pipe, they can rust and if they have been abandoned for a while no telling what's gotten into it.

[John76]

See my attached scribble.

The metal line that runs under the driver's side is the fuel return line (for carb models) or the fuel supply line for Tiis.

The plastic lines that you removed running through the cabin were for  (1) the fuel supply from the tank to the mechanical fuel pump, and  (2) the vent line from the vapor tank in the trunk to the charcoal canister in the engine bay. You need to properly vent your tank if #2 items are removed. 

 

[Son of Marty]

I did find a Holly fuel pressure regulator with a return port it states that you need a fuel pump that's rates above 5 psi for the regulator to work other than that it's slim pickens for low pressure return regulators.

[John76]

2 hours ago, Son of Marty said:

slim pickens for low pressure return regulators.

Good point!  The low pressure fuel regulators I have looked at all have a minimum initial pump pressure...usually above 7-10 psi before it can regulate it down to 2-3 psi.

[2002iii]

I have an electric fuel pump that feeds  dual Weber 40 dcoe's through the metal return line, with a 3 psi regulator with no return. Haven't had any issues yet.

[Oldtimerfahrer]

15 hours ago, 2002iii said:

I have an electric fuel pump that feeds  dual Weber 40 dcoe's through the metal return line, with a 3 psi regulator with no return. Haven't had any issues yet.

Why do it simply, if you can create a complex german style slightly overkill solution....I am though all for electric pumps with king filter with variable pressure regulator...and no return line....yikes, its worked for 20 years, why fix a running system?

Andrew