Hi guys, haven't been logged in here for a really long time, but having trouble figuring out an issue.
Researched several old threads covering the various gas tank Vent designs. Mine is a single 3/8 feed from the sender with no return, and 2 Vents off the Passenger side corner of the tank. Internally, the 1/2 inch vent is short, venting the near corner, while the 1/4 inch tube traverses to the opposite corner of the tank.
Anyway, having owned this car since 1981 it appears I have a part missing that is supposed to be connected to the end of the vent hoses. The Tank Fuel Vent Surge (403846) with the Restrictor on the tip. (403844)
There's a parts outlet on ebay that offers an aftermarket version of this, with instructions to fill the unit with cotton before installation... https://www.ebay.com/i/332553603235?chn=ps
Has anyone on here used this Vent Surge, and what are the chances of it reducing the gas fumes in my garage/house?

I had one of those and it does not help with the fumes. I tried a lot of different things and ended up using a later model charcoal canister vent system. It eliminates the fumes from the tank but I still get fumes from the carb while the gas vaporizes from the bowls. My garage still stinks after I drive the car. Later models vented the carb to the charcoal too. Maybe we should upgrade to fuel injection.

Bill, Holley or Q-jet?
Come to think of it, I'm actually not sure if the fumes are coming more from the tank or the Carb.
I just assumed the tank hoses since they are wide open to the atmosphere.
I keep it in my garage during the summer as I have for the 26 years I've owned my house.
Typical 3 BR split-Level with the garage beneath the BR and master bath. When I go from my BR to the bathroom the fumes are strong...seems to be worse these last two driving seasons, or else I'm becoming more sensitive as I get older. Getting concerned about the health hazard.

Could you provide more details about your canister setup?

That's the stock 68-69 vent thingy which originally had a piece of like lawn mower air cleaner foam inside it.
Mine doesn't have anything in it but I ran a hose off of the top of it, then up as high as I could get it then back down.

I don't don't ever have any fumes in the garage but I usually don't have more than a half tank or less of gasoline when I bring the car back home.

Cotton? Ya, no. There are versions of the Vent Surge Valve that come with a foam insert (just like factory was supposed to). Plus, the one you linked to doesn't have the restrictor valve fitted to the top -- that actually prevents (in theory) the smell from escaping...

The Vent Surge Valve you want is In Line Tube P/N: INL11406 @ $22.00
If you need replacement hoses then instead of that one get INL11407 @ $29.00
The Vent Hold Down Bracket is INL11945 @ $12.00

The downside is that none of the reproduction Vent Surge Valves include the top valve. The original top restrictor valve was very similar to the vent valve that goes on the rear axle.

Buy that valve (P/N: INL11314) and graft the valve onto the INL11406.

Does you car have a PCV System that gets air from inside the Air Cleaner? Valve Cover Breathers can let crankcase smells escape through the breathers. Something to consider...

Thanks guys...
Bruce, do you think the addition of the Top Valve will increase my chances of reducing fumes?
And, does the Vent Surge Valve need to be near zero degrees vertical in order for the Top Valve to function correctly, or does it not matter?

Provided the gas tank vent is your issue, then yes, and yes the restrictor valve has to be vertical in order to "seal" when the pressure in the tank is within norms.

Go to home depot, the lawn mower parts section. Get a lawn mower air filter, the one made of foam. Cut a piece of that and insert it into the end of the fuel vapor/liquid separator. You want to mount the separator as high as possible with the 2 fitting ports pointed down.. An additional hose can be installed from the separator top and extended as high as possible the looped down to prevent fuel from leaking onto your car. Some have taken this hose and dumped it at the end of the frame near the bumper. An additional small piece of the foam can be inserted in the end to keep the bugs out.

A common issue with the 69 vent system is fuel leakage from the vent if stored on an incline or with a full tank of fuel. Resisting the urge to top off the tank helps, but fuel surge can also cause leakage out of the vents. That's the purpose of the extended tube to the bumper, to keep that fuel away from the car and hot exhaust.

You should have a non vented fuel cap on that car.

An enclosed air filter will help to keep fumes in as compared to an open element.

You should check all your fuel lines for leaks since you've had the car for a while and the fumes seem to be getting worse. Sometimes there will be a build up of dirt or oily substance on the hose at leak points. Trace and check all fuel lines and connections.

Might look into adding vents to exhaust fumes out of the garage. Maybe some of your vents are blocked if you have any. The garage should be properly vented to keep the fumes out of the garage. The fumes are heavier than air so will tend to concentrate near the floor.

You can install a later model, like 71 or 72 EEC system, but your 1 vent short on your tank and I'm not sure you could tee into one of the current vents and get the system to function correctly. I'm also not sure that this system would eliminate fumes from the carb area.

I haven't seen that pressure valve Bruce describes, but it would have to allow flow in and out of the tank to function properly as a vent.

I have an Edelbrock carb with the 1/4" thick heat insulator gasket. I am using the small 1970 vapor separator in front of the gas tank. The tank vent lines run into it, then a hard line goes up to the engine bay to the canister. A vacuum line and a purge line run from it to the carb. I found used parts on ebay.

Check the area around where the filler neck meets the tank. They corrode there and may not leak but they will vent fumes.

Here's a good thread that discusses fixes and installation of the charcoal canister. https://www.chevelles.com/forums/45-...n-eec-car.html


Another good article..the more you know........http://www.superchevy.com/how-to/add...or-ecs-repairs

Please excuse me for just seeing this and late in providing my insight

Owned my 67 since June 2005 and never the smell of gas in my Detached Garage

In Aug 2018 all of a sudden when opening up the Garage Door I could smell Gas

Had the car schedule for an Appointment for a New InTank Fuel Pump
my Mechanic when he dropped the Gas Tank found that it was leaking,
had several Holes on the Top of the Tank,
but the 50+ Yr old Vent was working fine
and is now attached and doing it's job to the New Holley Sniper #19105 Gas tank that is installed

So it may not be a Venting problem as such but the Gas Tank or a Fuel Line leaking

Also not sure how much or old you lines are but the older lines do not like todays gas and the fumes will actually vent through the rubber.

I installed a Tanks Inc. roll over vent in the top of my tank and ran a hose from it to a 07~11 Dodge Nitro vapor canister filter (charcoal filter) and mounted it in the rear bumper corner above the fuel fill, it's about five inches long and maybe 2 inches in diameter. The cap on the fuel fill is "vented" meaning it's a check valve that lets air in but not out. I capped off all the other tank outlets.

There's no gas smell in my garage regardless of how long the garage is shut or full or empty tank.

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