Fuel Vent questions 1970 383 Challenger RT/SE non-ecs

[mtterry]

So I need some logical diagram or assistance in understanding where theses lines go.

My car was in peices when we bought it.


I ordered a tank with a vent hole previously before really digging deep on this.
I ordered fuel lines prebent. So I have two lines coming up the passenger rail. One clearly goes to the tank. The other  I assumed went up to the fuel filler vent line as well?

I keep reading that the filler neck vent simply goes through the trunk pan and vents out into the rail? Is that right? What was the second line up to the front of the car for.

Any insight is appreciated!


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[anlauto]

First...in 1970 a Challenger that is NON-ECS, you should only have one 5/16" main fuel line going front to back, that's it. (not two)
Secondly, your fuel tank should have one 1/4" nipple on the top passenger's side.
Next...The fuel filler tube, from the quarter to the tank should have one 1/4" nipple on the top of it.

Basically those two nipples are connected through 1/4" metal lines and rubber hoses.... The metal line goes down through the large oval hole in the trunk floor (with plate/gasket) and through the long oval hole in the frame rail over to the fuel tank...

[mtterry]

First...in 1970 a Challenger that is NON-ECS, you should only have one 5/16" main fuel line going front to back, that's it. (not two)
Secondly, your fuel tank should have one 1/4" nipple on the top passenger's side.
Next...The fuel filler tube, from the quarter to the tank should have one 1/4" nipple on the top of it.

Basically those two nipples are connected through 1/4" metal lines and rubber hoses.... The metal line goes down through the large oval hole in the trunk floor (with plate/gasket) and through the long oval hole in the frame rail over to the fuel tank...

This is exactly what I needed. So the filler tube vent is a loop back to the tank. The plate in the trunk has two openings, so I'll only use the one main feed 5/16. That loops back down to the tank, and I can get rid of the 2nd line I already installed lol!

Thanks!

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[anlauto]

YES, you only use one of the two holes on the oval plate. 1970 Cuda used both so one common part for both models.
YES, from the factory 1970 383 non-ECS Challengers and Barracudas only used one 5/16" main fuel line front to back.

In 1971, that is when the ECS system was used across the board and the E Bodies then required two 5/16" lines front to back.

[headejm]

On my 1970 Challenger, the filler tube is not vented back to the tank. The filler tube vent line is stuffed into the frame rail. My tank has no provision for an extra tube and the factory tube is too short to reach the tank.

[anlauto]

Interesting...   I know 1970 Cuda travels into the trunk, then back out and dumps in the frame rail....so I guess anything is possible ?
Maybe your tank was replaced with a nippleless one at one time, and that was someone's solution ?

[mtterry]

Interesting...   I know 1970 Cuda travels into the trunk, then back out and dumps in the frame rail....so I guess anything is possible ?
Maybe your tank was replaced with a nippleless one at one time, and that was someone's solution ?

I have seen several comments and posts suggesting that the filler vent just goes to the frame rail.
The best solution is to take it back to the tank over dropping into the rail?

Would that not allow air to escape and create a vacuum almost ?  If that sounds stupid... My bad.. I'm a computer guy that's trying understand...

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[headejm]

These aren't "comments ". The factory built mine with the vent line in the frame rail.

I suppose it wouldn't be a vent if you put the line back to the tank since that is what you are trying to vent.

[mtterry]

These aren't "comments ". The factory built mine with the vent line in the frame rail.

I suppose it wouldn't be a vent if you put the line back to the tank since that is what you are trying to vent.

No disrespect intended. I only have seen comments on forums, etc. I have yet to find any service manual or documentation to confirm it just vents to the rail.

In regards to taking it back to the tank, yea that's what I inquired about in my last post.

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[jt4406]

Code Select Expand

The factory built mine with the vent line in the frame rail
Mine too!  (LA built May 1970 318/3spd deputy, no Calif emissions)
I believe it was meant to function as an overflow as well as a vent.
Just my .02

jess in ky

[headejm]

I'm not sure it was also an overflow since the vent line rises significantly above the fuel filler inlet. Plus, it would seem kind of dangerous to plan on dumping fuel near the mufflers.

[jt4406]

"Overflow" may not have been a good choice of words, think of how a full gallon of gas expands a plastic jug when it heats up (like setting in the sun). If you "fill'er up" and put the gas cap back on, and it's warm outside.....  would it not have to go somewhere? Just speculation on my part.  jt

[70vert]

My 70 Challenger Convertible is set up this way as well (vents into the frame rail), it was a 383 now 440. I thought it odd, and in fact I can occasionally smell gas after pulling back in the garage. I'm not original owner but have had it for 40 years and doubt it was modified like this.

These aren't "comments ". The factory built mine with the vent line in the frame rail.

I suppose it wouldn't be a vent if you put the line back to the tank since that is what you are trying to vent.

[1970Cuda]

I agree with anlauto on the venting for the 1970 'Cuda (non-ECS), and it definitely vents into the frame rail. I bought a repro kit for it and it has this interesting "Z" tube that only fits (snuggly) into the frame rail.

Obviously were discussing a Challenger, and I've looked at the service manual and studied it fairly closely and it is definitely NOT clear on the venting and where the tube goes (that I can see).

Picture is from my 1970 'Cuda. It was formerly an ECS car that I converted to a Federal car.

In the Challenger rail, is there a rather large opening?

[anlauto]

This is interesting, I've never come across a 70 Challenger that just dumps in the frame, even though every 70 Cuda does dump in the frame.

Do they even make a fuel tank that DOES NOT have the 1/4" nipple on the passenger side ? For you guys with 1970 Challengers dumping in the frame, what does your gas tank look like ?