Just a thought, can I block off the vent that is on top of the tank,that go's to the charcoal canister up in the engine bay ? Then just use a vented gas cap... I really don't want to clutter up the engine bay with emission stuff if it's not nessesary.... I have one on the way if I need it....
The vent tube can go any where. On my '60 Falcon the vent starts on top of the tank next to the filler neck then snakes around the rear panel exits behind the rear bumper.
so that canister that is on the passanger side of the engine bay that has a pipe from the header is coming from the gas tank??? do you need it to be there
The system functions as follows: Changes in atmospheric temperature cause the gasoline in fuel tanks to expand or contract. If this expansion and consequent vaporization takes place in a conventional fuel tank, the fuel vapors escape through the filler cap or vent hose and pollute the atmosphere. The fuel evaporative emission control system prevents this by routing the gasoline vapors to the engine where they are burned. As the gasoline in the fuel tank of a parked car begins to expand due to heat, the vapor that forms moves to the top of the fuel tank. The fuel tanks on all 1970 and later cars are enlarged so that there exists an area representing 10-20% of the total fuel tank volume above the level of the fuel tank filler tube where these gasses may collect. The vapors then travel upward into the vapor separator which prevents liquid gasoline from escaping from the fuel tank. The fuel vapor is then drawn through the vapor separator outlet hose, through the 3-way vapor control valve (1970 only), then to the charcoal canister in the engine compartment. The vapor enters the canister, passes through a charcoal filter, and then exits through the canister's grated bottom. As the vapor passes through the charcoal, it is cleansed by hydrocarbons, so that the air that passes out of the bottom of the canister is free of pollutants. When the engine is started, vacuum from the carburetor draws fresh air into the canister. As the entering air passes through the charcoal in the canister, it picks up the hydrocarbons that were deposited there by the fuel vapors. This mixture of hydrocarbons and fresh air is then carried through a hose to the air cleaner. In the carburetor, it combines with the incoming air/fuel mixture and enters the combustion chambers of the engine where it is burned. On both systems, there still remains the problem of allowing air into the tank to replace the gasoline displaced during normal use and the problem of relieving excess pressure from the fuel tank should it reach a dangerous level. On 1970 systems, the 3-way control valve accomplishes this. On 1971-77 systems, the special filler cap performs this task. Under normal circumstances, the filler cap functions as a check valve, allowing air to enter the tank to replace the fuel consumed. At the same time it prevents vapors from escaping from the cap. In case of severe pressure within the tank, the filler cap valve opens, venting the pollutants to the atmosphere.
It is a felony to remove emissions controls unless a car is for off road (racing) use only. Actually - of all the pollution junk put on cars, that one is a good one. It uses no power, functions well, takes up very little room and has no parts that wear out.
You can very easily make your nonvented cap into a vented cap. Look at the back and you will see a hole in the middle. In that hole is a check valve. It allows air into the tank, so it dont pull a vacuum as the gas is sucked out, but will not allow air out of the tank. All you have to do is take a drill the same size as the hole and drill out the check valve. Its plastic so very easy to do. You can verify it is now vented by blowing through it. Then you can plug up the vent line on top of the tank.
Thank you for the advise, I do have a canister on it's way. I will install it and see if I can live with it under the hood... If not then I will block it off and create a vented cap...I just finished restoring my gas tank, who ever had it before put a self tapping screw in the corner with a rubber washer for a drain..lol the screw was just about rusted to dust.. so I broke out my mig welder and welded the hole shut, then cleaned and painted it...
