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1941 Master Deluxe, 216

Received a new gas tank. After shipping cost and availability were taken into account I purchased a poly 16 gallon tank for my 41 from Chevys of the 40s.

Not quite sure what to do with this. This tank has a vent on it that they recommend installing above the fill tube. Have any of you had to install a vent and if so where? I was thinking of running it along side the fill tube and mounting it to that just below where it leaves the fender. Not above it but close. Any foreseeable issues with this? Why does this tank need a vent when the old ones did not? Do I have to have the vent?

Trying to remember if the tank mounts flush with the floor above it. This one needs space on top for a vent line and the fuel line. There is a trench to run the fuel line in but the vent looks like it my hit the strap if I run it forward.

The vent is a 50s/60s safety addition. It was designed to allow air to come out of the tank and not blow directly out the filler neck past the gas station nozzle as the tank is being filled. It should connect to a little nipple that you would have to weld to your filler tube just below the cap.

Art

That's what I did only at the top made a loop with end pointed down so water would not get in the tube. Just don't fill the tank so gas is up high in the fill tube otherwise you might get some gas come out the vent tube

Dick

If you don't have a vent, you can't drive very far. It creates a vacuum in the gas tank and the pump can only do so much before you starve for fuel. In a lot of old cars the vent is in the gas cap.

Are we talking about a hose that comes from the top of the tank and tees into the filler tube just below the cap like beachbum describes? I guess that's a vent of sorts. It isn't "the" vent though, because it does not go clear outside. It is still under the cap. That one allows you to fill the tank more easily without blowback. My 1936 Pontiac has it from the factory.

on a 1937 sedan the gas cap is vented

The poly tank I received has a separate place to attach a line for the vent. They included a 'roll over' vent to attach to the other end of the line. Instructions say to place this above the fill tube on the frame of the car. Issue I saw was that the fill tube is high in the fender and there is no place on the body of the car to attach it there.

I think I will take the advice of others in this thread and make a mount to attach it to the filler neck as close to the edge of the fender as I can. As long as I am not placing so much gas in the tank to fill up the complete filler neck I should have no issue.

Instructions also said to ground every metal part attached to the tank since it is a poly tank. Since the sending unit requires a ground to function I am running a ground from that to the frame. Just grounding the metal parts of the filler neck to the sending unit.

Thanks again for all of the help.

That is a great plan. Please update us on how well the poly tank fits. I have had some issues with the fit of replacement steel tanks.

My sons fit the tank last weekend before we started mounting the sender or filler neck etc. They said it fit the stock location ok and there should be room for everything. There idea was it was easier to check when it had nothing bolted on. Their big comment was that the thought it was lighter and easier to maneuver. There is a large gap in the middle where the baffles are that they said is helpful to grip it to position it where it should go.

On this one I am just going to bolt everything on the tank and check the connections after they are done. They want to do the under car work and I have no reason to believe they will not be able to figure it out.

That sounds very promising. We had a real bear of a time installing a “replacement” metal tank in a ‘49 3100.

The neck configuration was so far off that it did not fit the opening in the right rear corner panel of the cab. We had to cut the filler tube, grind it to fit in the right position, and re-weld it.

The tank was the correct overall dimensions. The problem was that the tank halves were stamped with much sharper angles than the original. So it would not sit in the saddles that are welded to the cab floor. We had to modify the saddles.