Projects Gas tank vent, what is that??

@miki562 :
Get a vented fuel cap and you don't need to make tubes, filters etc.

 

Isn't that what we are all dreaming about?

 

Only if your filler cap is outside the trunk. Not everyone's is.

 

then newer gas caps have a one way valve in them for emmisions so when the evap system is not being purged , it will allow take up air in but no vapors out . it has to be for a 76 and later vehicle so the cap threads might be a problem , but on the older ones a exterior vent is prefered . make sure you put 2-3 loops in the line as it will also help control vapor bleed off . I have built several cars were it had a charcoal canister on it hooked up to control the gas smell in the guys garage , its a simple line to control the purge valve and line to the carb port and the thermal switch . hardest part was hiding the canister and running the lines so they wouldn't attract attention , but make them polished hard lines and no one notices them . .

 

i am kind of surprised you have not had any issues with your tank without a vent. some idiot that owned my truck before me plugged the fuel tank vent and on 1 hot day the pressure that built up in the tank forced gas into the engine and filled the entire engine full of gas. all that headache was caused by the tank not being able to vent. unplugged the vent line and never had an issue since. i know it was pretty confusing to me when i was pulling the carb and fuel just kept pumping out the line with the engine off.

 

That's right. Sorry, I didn't consider this case.

 

Battery boxes need to vented to the outside too.

 

so all i need to do is add a tube with a loop higher than the tank and run the tube out the floor with a gas filter on the end to my unvented tank.

 

In theory, yes, but you also have to plan for gas fumes and leakage in the event of a roll over accident. Exploding fumes in a garage or burning to death in a crash aren't cool !