How to run a return fuel line

[ACUDANUT]

I have a electric fuel pump and I am concerned about bogging down the pump. Is there a fuel filter that has 2 holes at the top to relieve too much pressure going to the carb ?

[cdr]

the proper way you will need at least a 3/8 return line with a bypass regulator near the carb

[ACUDANUT]

3/8 return fuel line ?  I know all about fuel regulators, but they still can bong down a eclectic fuel pump and in the end,killing their lifespan.

[cdr]

3/8 return fuel line ?  I know all about fuel regulators, but they still can bong down a eclectic fuel pump and in the end,killing their lifespan.

not with a regulator that returns the extra fuel back to the tank. threecents 

[cdr]

this is one example with a Holley type carb.

the line fitting on the right side is the pressure  [supply] line & the left is the return off of the bypass regulator to the tank.

[ACUDANUT]

Never seen a system like that on a Holley. 

[303 Mopar]

I have a electric fuel pump and I am concerned about bogging down the pump. Is there a fuel filter that has 2 holes at the top to relieve too much pressure going to the carb ?

NAPA has this fuel filter with 1 inlet and 2 outlets for a return line.  I have this set up on my '68 Charger, '70 Cuda, and '71 Challenger and works with no issues. My Challenger had the Mallory electric fuel pump and ran great.

[Yatzee]

Surprisingly, the return fuel line should actually be one size larger than the supply. Line restriction caused by friction against the walls of the fuel line coupled with distance ( usually about 18 ft ) makes the pump work hard just to return the fuel back to the tank. This light back pressure can affect the  the movement of the regulator diaphram causing variations in forward pressure. Not so much so once you pass the 30 p.s.i. range for fuel supply like TBI. Ideally to have an totally accurate fuel regulator there should be no line friction or back pressure from the return side line.   

[ACUDANUT]

I have a electric fuel pump and I am concerned about bogging down the pump. Is there a fuel filter that has 2 holes at the top to relieve too much pressure going to the carb ?

NAPA has this fuel filter with 1 inlet and 2 outlets for a return line.  I have this set up on my '68 Charger, '70 Cuda, and '71 Challenger and works with no issues. My Challenger had the Mallory electric fuel pump and ran great.

Do you have a napa part # ?

[John_Kunkel]

I have a electric fuel pump and I am concerned about bogging down the pump.

Low-pressure electric pumps work fine when dead-headed, they won't "bog down".

[birdsandbees]

I have a electric fuel pump and I am concerned about bogging down the pump.

Low-pressure electric pumps work fine when dead-headed, they won't "bog down".

Exactly with 4 to 10 psi, I've never run a return line on an airplane in 25 years, unless it was FInjected and using a 50+psi pump. Can't see it being an issue on a car.

[cdr]

I have a electric fuel pump and I am concerned about bogging down the pump.

Low-pressure electric pumps work fine when dead-headed, they won't "bog down".

Exactly with 4 to 10 psi, I've never run a return line on an airplane in 25 years, unless it was FInjected and using a 50+psi pump. Can't see it being an issue on a car.

it solves vapor lock & fuel boil problems!!! it gets HOT in Texas.

[cdr]

Surprisingly, the return fuel line should actually be one size larger than the supply. Line restriction caused by friction against the walls of the fuel line coupled with distance ( usually about 18 ft ) makes the pump work hard just to return the fuel back to the tank. This light back pressure can affect the  the movement of the regulator diaphram causing variations in forward pressure. Not so much so once you pass the 30 p.s.i. range for fuel supply like TBI. Ideally to have an totally accurate fuel regulator there should be no line friction or back pressure from the return side line.   

This Only applies when running a belt type fuel pump or a hi volume , pressure electric pump

[ACUDANUT]

I have a electric fuel pump and I am concerned about bogging down the pump.

Low-pressure electric pumps work fine when dead-headed, they won't "bog down".

Exactly with 4 to 10 psi, I've never run a return line on an airplane in 25 years, unless it was FInjected and using a 50+psi pump. Can't see it being an issue on a car.

I run a electric fuel pump and the carb does not like more than 7 psi's.  Otherwise it makes my Holley spew fuel up the overflow tubes in the center of the carb.

[birdsandbees]

Then you have the wrong pump for the carb. I see what you're trying to do though, with a relief valve I presume and a return line.

[John_Kunkel]

If a low-pressure pump still puts out too much pressure for the carb, there are regulators (like the Holley 12-80)  that don't need a return line.

[303 Mopar]

Do you have a napa part # ?

http://www.napaonline.com/napa/en/p/PSX23040/PSX23040_0429463117?interchange=1

[lukedukem]

I have a electric fuel pump and I am concerned about bogging down the pump.

Low-pressure electric pumps work fine when dead-headed, they won't "bog down".

Exactly with 4 to 10 psi, I've never run a return line on an airplane in 25 years, unless it was FInjected and using a 50+psi pump. Can't see it being an issue on a car.

Agree.
I have a Holley pump that puts out about 5-7 psi, and I do not have a return line. Car runs fine with a 750 eddy carb.

Luke