Tank venting

[Vernon Whiting]

Hi ,
I am new to the forum,
I am rebuilding a gt and would like to have an idea of what to do with the tank venting
there is no pipes currently with the vehicle
and i an looking at an outlet from the the filler neck and two on the tank itself
could anyone let be have adetailed diagram as to where each outlet goes and the hight required for the venting pipes etc.
do i need the charcoal filter (not there at the moment) or can i get round this.
I am in the uk and would like to know where best to pbtain an exhaust system.
regards
vern

[baronbors]

http://clubs.hemmings.com/clubsites/...h/TankVent.pdf
10 SECONDS USING THE SEARCH ENGINE ON THE SITE- TRY IT- IT IS A WONDERFUL DEVICE

[namba209]

Originally Posted by Vernon Whiting I am in the uk and would like to know where best to pbtain an exhaust system. regards vern

Vern, hang around on the site, Baz, a fellow countryman, should be able to telll you when he comes on the site.

[ungermm]

Vern, You should replace the lines with something other than vinyl tubing so you don't have the same problem down the line. I ended up using plastic (1/4 inch, I think, refrigerator ice machine water line which is very inexpensive and should not rot out. The cannister is not a requirement to run your car. And, most people run a Weber carb that doesn't hook up to the breather lines from the cannister anyway. Jerry

[ddoyle]

"(1/4 inch, I think, refrigerator ice machine water line"

I would be worried about using something that is not rated for fuel in my system. When I replace a rubber fuel line anymore I use hose rated for fuel injection. Much higher burst rating and seems to last much longer. Not sure what I would use to replace the plastic/nylon lines on the opels. I know that you can buy the hard plastic fuel lines and hose ends now.

Dan

[ungermm]

I'm not sure why Opel used the once soft and flexible vinyl lines in the first place. They all break down from age and gas vapors. It seems to me that they weren't rated for use in a gas environment. Since the lines are only vent lines and there isn't really any pressure build up, I think the plastic refrigerator lines will work fine. They seem to be holding up better than the original vinyl ones I had. I'll let you know in another 5 years how they are doing. The original setup did use plastic lines from the cannister to the carb anyway. I'm pretty sure the whole concept of the system is to allow the gas tank to breath and not blow up and to redirect the gas vapors into the carb to burn up in the engine rather than escaping to the air we breath. Jerry

[RallyBob]

Teflon lines work very well for use with fuel. In fact for pure racing use teflon fuel lines (stainless steel braided outer covering) are prefered, since they don't break down like the (stainless steel braid covered) synthetic rubber lines can after 5-7 years. And they are rated for ridiculously high pressures too.

Bob

[ungermm]

I have a feeling the refrigerator lines that I mentioned are teflon. They are not like hard plastic, kinda softer bendable stuff, but, harder than vinyl fish tank air hose. They are 1/4" OD and only a couple dollars at your local hardware store for enough to do the whole car.

[namba209]

Personally, I'd go with the fuel vapor vacuum lines. They're designed and formulated to be used as tank vent lines. Unprotected teflon tubes, IMHO, are a bad choice. Once you've put a crimp in them, by trying to bend them past a certain point, specifically at the front left vent fitting on the tank, they become unusable because they'll crack at the crease. RallyBob is correct about the high pressure steel braided teflon can be used. I've seen them used in applications in excess of 3500 PSI and 1200 degrees F, where there is a fair amount of flex on the lines and they seldom need replacement, usually caused by the steel braiding being rubbed away.

[kwilford]

There's a whole Forum section devoted to this topic:
http://www.opelgt.com/forums/fuel-ta...lters-venting/
A search for some key words gives:
http://www.opelgt.com/forums/search.php?searchid=189105
That gives a few interesting threads to read without taking an entire night. Some might even have been authored by yours truly
IMHO, the best choice is 3/8" (IIRC) fuel hose.
HTH

[ungermm]

Originally Posted by namba209 Unprotected teflon tubes, IMHO, are a bad choice. Once you've put a crimp in them, by trying to bend them past a certain point, specifically at the front left vent fitting on the tank, they become unusable because they'll crack at the crease.

I agree. My refrigerator lines started to crack after a couple of years. Sorry if anyone else used these. I substituted them with rubber lines from the hardware store used for garden irrigation. They are called Mister Mister lines. However, a safer choice, although more expensive, would be fuel line. Just trying new things and being cheap. One thing that I learned is that I didn't have to pull the tire shelf in order to replace the lines.
Jerry

[grslightng02]

You can order replacement tubing from OGTS. They will send it to you, along with a diagram of how to replace the tubing. Only problem you may have is the dimensions on how long to cut each tube, if your current tubing has disintegrated.

I have seen others on this site also replace the clear tubing with fuel line (black) tubing available at your local autozone, kragen, napa etc. And make sure you buy plenty of the silver hose clamps that tighten with a screw.

Since the gas tank was technically "inside" the GT a ventilation system was present to prevent vapor build up in the cabin. I'm sure everyone who's driven a GT with bad vent lines to their gas tank will understand! PEWWWW!

Also, since you're new to the GT thing and you're working on your car, consider removing the gas tank, having flushed, remove the metal mesh "sock filter" inside the tank, and install new fuel lines and fuel filter(s).

Happy Opeling!

[grslightng02]

Oh yeah.... and the charcoal filter is nice... but not necessary. Many if not most GT owners I've run into don't bother attaching them anymore. Unless you want to keep the car truly original.

[First opel 1981]

SOme also redo the gas tank vent lines in steel tubing.



Here is a whole thread devoted to venting (there are more threads as well)
http://www.opelgt.com/forums/opel-te...e-rethink.html