carrman
Senior Member
Getting bit by the EFI bug, contemplating the Holley Sniper using an RobbMc PowerSurge tank. Read the instructions, and it states I need a return line to the fuel tank. What have those of you with EFI done to add that?
EFI and fuel return line
- Thread starter carrman
- Start date
D
Deleted member 220
Guest
I dropped my tank and welded a bung on and ran 3/8 steel line which sucked. Dont for forget to put a drop tube in u dont want the gas just spraying back in the tank
carrman
Senior Member
Well that seriously sucks.
D
Deleted member 220
Guest
Try this with a fitech efi. Its what ill be doing on my next efi swap so i dont have to do a return line
bajajoaquin
Senior Member
If you're using the RobMC surge tank, don't you do that so you don't need the return line?
Nice!
carrman
Senior Member
I thought so until I read the instructions and it shows needing a return line to be added.
carrman
Senior Member
Step 5: CONNECT A RETURN LINE FROM THE POWERSURGE TO THE FUEL TANK
A ¼” or larger return line must be connected between the “R2” port (1/8 NPT) on the PowerSurge and the fuel tank. Many cars built in the 1960’s or later came from the factory with a ¼” return line connected to the fuel pump or fuel filter. If your car has such a return line, disconnect it from the stock fuel pump or filter and connect it to the "R2" port on the PowerSurge. Then cap the ¼” barb on the stock pump or filter so it doesn’t leak fuel. If your car does not have a return line to the fuel tank, add one. Our 1965 Falcon test car did not have a return line. We made one from ¼” steel brake line (available at most auto parts stores). It comes in 6 ft lengths and is easy to bend. Low cost, stock type, replacement sending units with provisions for a 1/4" return line are available for many cars. This fuel line will not be subjected to high pressure so fuel injection type hose is not required.
CAUTION! The fuel tank must have a vent. Some factory vent lines vent directly to the atmosphere; others are connected to a charcoal canister or a vent box. Make sure the vent is functional. Do not use the vent line as a return line for the PowerSurge unless the fuel tank has another vent (or at least a vented filler cap).
A ¼” or larger return line must be connected between the “R2” port (1/8 NPT) on the PowerSurge and the fuel tank. Many cars built in the 1960’s or later came from the factory with a ¼” return line connected to the fuel pump or fuel filter. If your car has such a return line, disconnect it from the stock fuel pump or filter and connect it to the "R2" port on the PowerSurge. Then cap the ¼” barb on the stock pump or filter so it doesn’t leak fuel. If your car does not have a return line to the fuel tank, add one. Our 1965 Falcon test car did not have a return line. We made one from ¼” steel brake line (available at most auto parts stores). It comes in 6 ft lengths and is easy to bend. Low cost, stock type, replacement sending units with provisions for a 1/4" return line are available for many cars. This fuel line will not be subjected to high pressure so fuel injection type hose is not required.
CAUTION! The fuel tank must have a vent. Some factory vent lines vent directly to the atmosphere; others are connected to a charcoal canister or a vent box. Make sure the vent is functional. Do not use the vent line as a return line for the PowerSurge unless the fuel tank has another vent (or at least a vented filler cap).
jct
Senior Member
Yatzee
Active Member
I'm not too sure about the Sniper, but Fitech uses an internal pressure regulator for all it's units so you do not require an external bypass regulator. I would imagine that Sniper works the same when you have an in-tank pump but because you using a Surge tank, you cannot send the excess fuel back to such a small container without inducing air bubbles and heating the fuel during pump operation. The pumps do get warm. Regardless, you have to send unspent fuel back to the tank where there is a large cooler volume. Remove your sender unit an drill a hole in the flange to accept a return line tube. You can use a small bulkhead connector but it's best to have the tube silver soldered in place. You can run neoprene fuel line from the engine bay back and secure it right alongside the feed line for neatness. Be advised that you should always go one size larger on the return line than the feed because a line that long will induce back-pressure right to the EFI unit ( or external bypass regulator ) making fuel pressure regulation inaccurate. You need the fuel to return to the tank effortlessly and not cause a high load on the fuel pump. The discharge return tube end should incorporate a bend the directs return fuel away from the pickup sock and float, pointing parallel to the nearest tank wall and sends the fuel swirling around the outer tank walls. It must discharge about 1/2 inch above the tank floor so it does not stir sediment.
Last edited:
I’d personally do this if I were to do it over again and just deal with a smaller tank size. 1968-70 Dodge Coronet / Plymouth Roadrunner Fuel Injection Gas Tank
But this is another method I thought about using.
But this is another method I thought about using.
bajajoaquin
Senior Member
Hmmm. This makes EFI much less interesting to me.
jct
Senior Member
what if you bought a 4 vent gas tank?
I am glad you brought this up. I am surprised I don't remember anyone mentioning this, seems like a real pain to do it right. It is not on my list of things to do, but will keep this in mind forthe future.
Appreciate the different options provided and will tag for future reference.
Appreciate the different options provided and will tag for future reference.
commando1
Old Man with a Hat
I have yet to see even one FI conversion that delivered 100% it claimed.
Find me one person who has not said, "Works great except..."
bajajoaquin
Senior Member
Wow. Not even on the second page of the other most recent EFI thread.
commando1
Old Man with a Hat
Just making sure that everybody knows all there is to any story.
Have I mentioned fuzzy dice.
carrman
Senior Member
I appreciate your feedback Stan. My carb works great until I turn a sharp corner and it sputters, or I'm at 5000' elevation and it won't start, or it's hot outside and she boils her fuel, or.....
commando1
Old Man with a Hat
So, are you going the FI route?
FI is the greatest thing to ever happen to engines. No argument here, whatsoever.
Read carefully my remarks about FI.
I have never seen anybody use an aftermarket FI conversion kit and get it running as advertised.
i.e. Bolt it on, let it go through the learning curve, and the ol 440 all of a sudden runs like a 2018 Lexus. That's what they promise....
Last edited:
bajajoaquin
Senior Member
We do read your comments carefully. That's why we are offering corrections when you once again change the criteria for being right.
I don't know any EFI that claims it will turn an old car into a modern car. They claim to improve drivability, throttle response, cold starts, and reduce or eliminate periodic carb adjustments. You said, "Find me one person who has not said, "Works great except...""
So I did.
Now the standard is a performance benchmark that doesn't exist. In fact, Every review I've read says that EFI won't fix everything.
You don't like retrofit EFI. That's okay. The benefits don't outweigh the costs for you. That's okay. But it's false to say that nobody is satisfied. It's false to say that aftermarket EFI claims to fix everything.
I don't know any EFI that claims it will turn an old car into a modern car. They claim to improve drivability, throttle response, cold starts, and reduce or eliminate periodic carb adjustments. You said, "Find me one person who has not said, "Works great except...""
So I did.
Now the standard is a performance benchmark that doesn't exist. In fact, Every review I've read says that EFI won't fix everything.
You don't like retrofit EFI. That's okay. The benefits don't outweigh the costs for you. That's okay. But it's false to say that nobody is satisfied. It's false to say that aftermarket EFI claims to fix everything.
Similar threads
