71DodgeDemon340
Well-Known Member
hey guys im intalling fuel line on my 71 demon and i was wondering if i need to run the vent line back up front or if i can leave it disconnected, also what purpose does it serve? emissions?
Fuel vent line
- Thread starter 71DodgeDemon340
- Start date
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I think if you leave it disconnected you will be pouring fuel out of it
as soon as the fuel level covers it up. I plugged mine on the 'Cuda
as I have a vent on the filler tube.
71DodgeDemon340
Well-Known Member
ok i am going to be running an edelbrock thunder series carb, do i need to run this vapor return line to my carb or just like you say can i cap it off? is it needed for emission use, whats its real main purpose, thanks.
I think it may have run to a charcoal canister in the engine compartment. Might
have been near the passenger front corner.
I wouldn't plug it off unless there is a vent on the filler neck. If it's not
vented, you can cause your tank to split. Ask me how I know. One other
thing is your gas cap may be vented. Mine was not with the flip open
gas door.
slantsixdan
=..=
71DodgeDemon340
Well-Known Member
thanks for the info, ok now for the next question it was a /6 car but im putting a 340 engine in it, do i still need the vapor return line, and im using an aftermarket carb, does the vapor return line run to the carb?
You do need a vent. You will have to but a vent on the fill tube as a 1970 duster has. On a 71 the line going front attaches to the Breather on the motor. Those five lines going to that second tube can all be capped. One is your vent. The rest were a collision impact protection system that was discontinued in 71. I am leaving mine in place for originality. But the hoses will be blocked and I will only use the one going front for a vent plus a 79 vent.
slantsixdan
=..=
The claim about "collision impact protection" is without any basis in fact. Capping off random lines because you don't understand what they're actually for is kind of lame. :roll:
I repeat my original advice: Do the job right rather than half-baked. Things will work best that way. It doesn't have to be the original '71-style system you go to; the '72-up system w/charcoal can is better, but a '71-style system hooked up properly is better than a pre-'71 open-type vent. The venting system is the same regardless of what engine the car has, with the minor exception of where the vent lines attach to the engine, as described in the linked post.
I repeat my original advice: Do the job right rather than half-baked. Things will work best that way. It doesn't have to be the original '71-style system you go to; the '72-up system w/charcoal can is better, but a '71-style system hooked up properly is better than a pre-'71 open-type vent. The venting system is the same regardless of what engine the car has, with the minor exception of where the vent lines attach to the engine, as described in the linked post.
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