Fuel lines

-
dartfreak75

dartfreak75

Restore it, Dont part it!
Joined
Aug 10, 2011
Messages
11,573
Reaction score
9,485
Location
Virginia
Since I accidentally cut my fuel lines cutting out my floor pans I'm gonna have to replace them with new. I have a few questions. On a budget what size and material fuel lines do you recommend? This is a street car with a mild 360. 2nd question mine has two lines one is a return line can I do away with that? Thanks
 
I would go with a 3/8 oem material. I got mine from inline tube and they were very nice and not that expensive. At first I tried to replicate a 3/8 line from my existing 5/16 and I failed pretty miserably. I normally can do most things, but the fuel lines have funky bends. I really wonder how they did them from the factory. You could splice together the vent line with a short section of rubber hose...
 
I'm doing my brakes in the copper nickel stuff and it's pretty easy to bend I like that. Do they make fuel line in copper nickel also? Iv seen aluminum (very expensive)
 
I just picked up a roll of steel 5/16 line for the Dart since it's getting all new fuel stuff - tank, lines, pump, etc. I tried the 3/8 stuff but it's all but non-bendable. the 5/16 stuff I think I can work with but it's still pretty stiff.
 
halfafish said:
I just picked up a roll of steel 5/16 line for the Dart since it's getting all new fuel stuff - tank, lines, pump, etc. I tried the 3/8 stuff but it's all but non-bendable. the 5/16 stuff I think I can work with but it's still pretty stiff.
Click to expand...
Iv seen the 5/16 in the copper nickel would that be big enough
 
I'm gonna try to get all the old line out in the morning and measure it to see how much I need. As far as the return / vent line do i need that or can I do away with it?
 
there is a difference in return and vent lines
you need to know what you are talking about in order to know if you need it

my guess is, it was not a return line because they didnt come with one from the factory
it may have been a vapor recovery line though, check to see if it goes into a charcoal canister

as for bending my own hard line, i wouldnt do it
its been a while since i ordered mine but i think i paid less then $80 for a pre bent 3/8th fuel line
 
diymirage said:
there is a difference in return and vent lines
you need to know what you are talking about in order to know if you need it

my guess is, it was not a return line because they didnt come with one from the factory
it may have been a vapor recovery line though, check to see if it goes into a charcoal canister

as for bending my own hard line, i wouldnt do it
its been a while since i ordered mine but i think i paid less then $80 for a pre bent 3/8th fuel line
Click to expand...
Yea it is the line that went to the charcoal canister I always thought that was called a return line.
 
dartfreak75 said:
Yea it is the line that went to the charcoal canister I always thought that was called a return line.
Click to expand...
It may or may not be iun that situation. Prob not. Prob is the fuel tank's vent to the recovery can. '72 has charcoal canister already? They work but unlike the earlier vapor saver when the internal foam filters break down and the charcoal breaks down those bits can (and do) make their way into the carb bowl. :(

First. Figure out the venting system you want to use for this car.

Second. Figure out the maximum fuel demand this car will ever see. Then decide the line size.
5/16 will do for most and exposes the least amount of fuel to the heat of the road and headers.
3/8 will have a little less resistance which will help with mechanical pump and for higher demand.
The plated steel will last a long time.
The stainless steel will slow heat transfer.

I'd buy a premade line and the larger clips if you decide on 3/8.
A lot of tight bends and getting that right requires some experience in bending tubes. Otherwise you'll waste a bunch of material.
Also for the hoses to really seal best should have a bubble or ridge. That's not a common tool.

If you find its just one section of the line that's bad, there's nothing wrong with using compression fittings to splice in a new section. Not to be trusted on high pressure and hydraulic lines, but fine for mechanical and low pressure fuel lines.
 
Mattax said:
It may or may not be iun that situation. Prob not. Prob is the fuel tank's vent to the recovery can. '72 has charcoal canister already? They work but unlike the earlier vapor saver when the internal foam filters break down and the charcoal breaks down those bits can (and do) make their way into the carb bowl. :(

First. Figure out the venting system you want to use for this car.

Second. Figure out the maximum fuel demand this car will ever see. Then decide the line size.
5/16 will do for most and exposes the least amount of fuel to the heat of the road and headers.
3/8 will have a little less resistance which will help with mechanical pump and for higher demand.
The plated steel will last a long time.
The stainless steel will slow heat transfer.

I'd buy a premade line and the larger clips if you decide on 3/8.
A lot of tight bends and getting that right requires some experience in bending tubes. Otherwise you'll waste a bunch of material.
Also for the hoses to really seal best should have a bubble or ridge. That's not a common tool.

If you find its just one section of the line that's bad, there's nothing wrong with using compression fittings to splice in a new section. Not to be trusted on high pressure and hydraulic lines, but fine for mechanical and low pressure fuel lines.
Click to expand...
Ok I'm gonna have to do some research on the venting systems. What are my options? I dont want to run the canister and all that emissions bullcrap in this car. I know there is a bigger line and a smaller line the bigger line when it the carb the other went to the canister. I cut the big one. The other one is fine but I'm not running the canister anyways so I was gonna just take it all out and rerun the fuel line.
 
dartfreak75 said:
If I'm not running the charcoal tank anymore what good would it do?
Click to expand...
without the canister, nothing
but I actually retrofitted a canister back into my duster, and it helps tremendously with the way the garage smells if the duster sits in there overnite

to the best of my knowledge, this is not an emissions thing, and it doesn't effect performance one way or the other

but...if you decide to not use the cannister, you can pull that line out, all the way to the back and put a little filter on there to keep crud from getting into the fuel
 
You got to look at your car, the FSM and TSBs.
from the MTSC it looks like 72 uses a manifold collecting the tank vents and then a line to the cannister.
1970
Heated Air Intake and "Vapor Saver" (Session 271) from the Master Technician's Service Conference

1972-3
1973 Imperial and  Chrysler Clean Air System Reference Service Repair Book from the Master Technician's Service Conference (Session 302)

The link Diymirage posted prob has more info.
The charcoal cannistor isn't that hard to open and replace stuff.
You can probably do a simplified version. The one on my '85 Grand Wagoneer was/is a bit of a pain 'cause it uses an unavailable electric solenoid on the carb vent and a two stage purge on the cannister.
 
diymirage said:
without the canister, nothing
but I actually retrofitted a canister back into my duster, and it helps tremendously with the way the garage smells if the duster sits in there overnite

to the best of my knowledge, this is not an emissions thing, and it doesn't effect performance one way or the other

but...if you decide to not use the cannister, you can pull that line out, all the way to the back and put a little filter on there to keep crud from getting into the fuel
Click to expand...
Thanks bud. I remember years ago when I drove this car I couldn't fill the tank all the way up because it would build pressure and spew out the filler cap overnight. Someone told me that it was because of that return line it wouldn't let the gas fumes escape and it would build in the tank that's why I didnt want to put it back. That may be completely wrong idk. That's just what I was told like 16 years ago by some old timer hotrodder at the drag strip lol
 
Mattax said:
You got to look at your car, the FSM and TSBs.
from the MTSC it looks like 72 uses a manifold collecting the tank vents and then a line to the cannister.
1970
Heated Air Intake and "Vapor Saver" (Session 271) from the Master Technician's Service Conference

1972-3
1973 Imperial and Chrysler Clean Air System Reference Service Repair Book from the Master Technician's Service Conference (Session 302)

The link Diymirage posted prob has more info.
The charcoal cannistor isn't that hard to open and replace stuff.
You can probably do a simplified version. The one on my '85 Grand Wagoneer was/is a bit of a pain 'cause it uses an unavailable electric solenoid on the carb vent and a two stage purge on the cannister.
Click to expand...
I'm looking in the service manual know I cant find it but I'm sleepy I'm going to bed I will look tonight when I get up lol thanks for your help
 
Ok done alot of research and this is what I have came up with. Found some copper nickel 5/16 fuel line. And this tank vent I can rubber hose to the top nipple on the fuel tank that goes to the canister and run it up as high as I can get it and use this vent fitting. Does this look like it would work good? I just want to get it vented properly so it doesnt cause any fuel issues to the carb and dont spew gas out of the filler when I have a full tank.

Screenshot_20200417-233043_Samsung Internet.jpg


Screenshot_20200417-232749_eBay.jpg


Screenshot_20200417-233053_Samsung Internet.jpg


Screenshot_20200417-233048_Samsung Internet.jpg
 
5/16 will support over 500 HP. If it was mine, I'd use the 1/4 return line for a .......wait for it........return line.
 
RustyRatRod said:
5/16 will support over 500 HP. If it was mine, I'd use the 1/4 return line for a .......wait for it........return line.
Click to expand...
Thanks this is what I'm confused about and I'm sorry for my ignorance on the topic I'm trying to learn. What is a return line and where is it at? I thought it was the line in the top of the tank that goes to the canister but was told I was wrong on that. I crawled underneath my car this morning and only see two the one going into the top of the tank that goes to the canister and the one coming out of the sending unit that goes to the carb.
 
dartfreak75 said:
Thanks this is what I'm confused about and I'm sorry for my ignorance on the topic I'm trying to learn. What is a return line and where is it at? I thought it was the line in the top of the tank that goes to the canister but was told I was wrong on that. I crawled underneath my car this morning and only see two the one going into the top of the tank that goes to the canister and the one coming out of the sending unit that goes to the carb.
Click to expand...

I said I would use it for a return line. I didn't say it was one. lol It sorta is, but it returns fuel vapors to the tank from the charcoal canister. You should be able to directly convert it to a liquid fuel return line. You'll need to make sure the tank is vented. Simplest thing would be to use a vented gas cap. Have you pulled the tank yet? You should, so that you can see exactly where that vapor line goes into the tank and if you have to modify anything to use it for a liquid return.......and also to clean it out good.
 
RustyRatRod said:
I said I would use it for a return line. I didn't say it was one. lol It sorta is, but it returns fuel vapors to the tank from the charcoal canister. You should be able to directly convert it to a liquid fuel return line. You'll need to make sure the tank is vented. Simplest thing would be to use a vented gas cap. Have you pulled the tank yet? You should, so that you can see exactly where that vapor line goes into the tank and if you have to modify anything to use it for a liquid return.......and also to clean it out good.
Click to expand...
I plan on pulling it in the morning when I get off work.
 
What would happen if I didnt run a return line and just vented it with the line in the top of the tank? Is a return line necessary?
 
dartfreak75 said:
Since I accidentally cut my fuel lines cutting out my floor pans I'm gonna have to replace them with new. I have a few questions. On a budget what size and material fuel lines do you recommend? This is a street car with a mild 360. 2nd question mine has two lines one is a return line can I do away with that? Thanks
Click to expand...
If I cut the fuel lines I would go ahead and cut it all the way through and put a piece of rubber hose over it and a couple hose clamps and call it a day on a budget...
 
dartfreak75 said:
What would happen if I didnt run a return line and just vented it with the line in the top of the tank? Is a return line necessary?
Click to expand...

Certainly not, but with ethanol laced gas, it's a really good idea. With a good return style fuel system, you can approach the driveability of EFI with a carburetor if done correctly. It's very good for keeping fuel temperatures down and pressure constant.
 
You must log in or register to reply here.
-

Back
Top