The Dodge Challenger Message Board

I just had my trunks pans replaced, and about to put the vent tube back in. Which one of the vent tubes from the tank gets attached to the vent line that goes up to the front of the car, leading to the motor (recycled back to carb)?

There are a total of 5 vent tubes on the tube that goes into the trunk (directly beginh the right wheel well) and 4 on the top (right side) of the new gas tank.

I just want to make sure before I put it back in.

james- it's the one by the tire!!!

must be a 71????

john mac

Yeah, it's a 71, I believe the first year w/ the ECS.
So it's the vent tube that is closest to the front(on the tank itself) of the car that goes to the steel line that runs up to the front of the car?

yes- correct!! I had some real fun trying to find the 3 port breather cap- 1 1/2 years- & $40.00 later for a greasy lump!!! cleaned up with no dents.

Yeah, I'm beginning to realize that. Thanks for your help Have a good Holiday season.

no problem!!! thats what the site is for!!!!!

John,

I just received the vent base plate and gasket from the parts supplier. The gasket makes sense,(three holes, two on one side one on the other), but what I don't get is the plate that it came with.
The plate has the same screw holes as the gasket and the base of the vent tube, but there are two grommets in the middle of the plate, only two holes, rather than an opening for all 5 lines?

The supplier documents that it is for 70-74, but it looks like all I'll need is the gasket that goes between the trunk floor and the vent tube.

I think the second one is for 1970 model- they only used a single vent tube up from the top of the filler neck tube down the trunk floor to expell excess fuel and vapour- I've only seen one tube- not two- just use the five holer and save the other.

JOHN MAC

FYI
1970 California delivered cars also had the N95 emissions package, basically the same as 1971 setup except for the metal shield that covered the lines between the frame rail and the gas tank was different. 1971 cars also have a notch on the left inner fender that the vapour line clamps to, 1970's did not have this.

Gord is spot on. My 70 has the NOX and ECS N95 option. The 3 way breather is needed if you plan on using the bowl vent connection on the original Holleys that routes to the breather. I disconnected it since I went with a Holley Street Avenger. the 4160 Holley was rebuilt but just doesnt have enough CFM to do diddly performance-wise. I need a 2 way breather!

Oops...not really Steve...rereading what I typed...that should read the right inner fender, not left. Vapour/fuel lines are routed on the passenger side.

It seems the 2 prong breather is an easier piece to find than the 3 prong one.

Emmissions vent tube...

1970 non ECS vent


View from below...line vents into frame rail. The oval hole in the frame rail where the line bends would be where the ECS (N95) vent lines would feed through and connect to the gas tank.

Here is a pic of a ´70 Barracuda. The vent lines looks like a joke, if you ask me.

christer wrote:Here is a pic of a ´70 Barracuda. The vent lines looks like a joke, if you ask me.

What the hell is that?!?!

Gas tank vent tube,(Evaporitive Control Sytem). It's purpose is reduce raw HC emissions and burned HC from both the engine's crankcase and the fuel tank on certain models. California versions have 4 tubes I think. However the tank must be vented or it may collapse and standard version have the engines crankcase re-directed to the carb base to be burned inside the engine. Since I have the flip top gas cap, non-Cali,mines setup like the pink car.

I knew the premise of the tube, i had never seen one bent over like in christers picture. That doesnt look like factory anything.

Moparman1972 wrote:I knew the premise of the tube, i had never seen one bent over like in christers picture. That doesnt look like factory anything.

I wouldnt know that moparman

So if you change out the 1970 Cali ECS tank (with the 4 vent tubes) and replace it with a standard non ECS tank, is it OK to just put a vented gas cap on? Do you need to do any more mods like drilling a hole at the top of the filler neck to allow the tank to vent through a line as shown in the previous pics?

My tank may need replacing soon and I have the Cali ECS but it is not connected to the breather in the engine bay (and probably never will be). So when I replace the tank I probably won't go for the 4 vent tube version.

Cheers

Piers

Depends on how you drive, but for any kind of racing (especially if that includes cornering), a vented gas cap will spil LOTS of gas on your rear quarter. Not something you want if you have a nice paintjob. At least, with the small tube vented in the frame, you won't have this problem.