My 38 coupe has the same problem, I chalk it up to poor design. There isn't much of an incline from the tank to the gashole... so it's hard to get it full without it running out first... If I ever tear this car apart, I'll move the tank to the rear like a sedan or sport coupe. somebody else said to listen to the fuel going in, when the pitch get's higher, you know it's about to run out... this works ok, but I look like a durn fool crotching down listening.. people probably think I'm huffin' the fumes or something..
it's cause you ain't holdin' your mouth right, no seriously it just needs a vent, if you have a vent it's not big enough,the only reason they are in the filler neck on newer vehicles is emissions, so that it can be closed off with the gas cap.
Add me to the folks who chalk it up to the modern pumps. I'm not so certain it's faster delivery, necessarily, but I believe the new valves aerate the gas - it comes out as an aerated "slug" of gas instead of a stream - this is why it makes it hard to "aim" it into the opening. I also notice new nozzles are more sensitive to backwash and will click off much easier than in the past... The only thing I've found that helps a little bit is to either a) slow way down or b) point the nozzle at the side of the tube so the gas hits it & swirls down the neck. Been doing B lately and getting full flow out of the nozzle for most of the fill. I have a vent too. It ain't that.
I had the same thing with my 46. My cure was to remove the gas sending unit and drill a hole in it and solder a short piece of 3/8 copper to which I attached a hose and routed it in the fender well. No welding or any thing dangerous since I had the sender in my vise and they revove very easy--Worked for me any way.
You can check with these guys on the vent. http://www.tanksinc.com/index.cfm they might have something that wouldn't require welding.
I think you'll find that the vent is part of the filler tube and not on the tank itself, it'll be that overflow drain at the lowest part of the filler assembly where you stick the nozzle in. It'll drain the spilled gas right back into the filler tube down low. Is there any way you can redo that 90? Or is that part of the steel tank, if it is rubber i'd be messing with that. One big reason i'd be looking at the 90 bend is the size of your filler neck/tube. It is huge compared to todays, i bet there is plenty of room for escaping air. The filler mouth isn't sealed off and a tight fit to the gas pump like todays cars, your filler entry is plenty roomy. As others have pointed out the fill rate is greater in todays pumps and it is probably that 90 causing the backup and not an escaping air issue. If it were an air issue the tank pressure would increase until it overcame the pressure of fuel going in and would spit the fuel back at you, not run down the side of the car.
Add a vent tube. Ray With's idea for adding the vent to the sending unit is a good retofit that won't require welding. Here is a picture of a replacement 49-52 Chevy tank, you can see the vent tube nozzle right beside the filler neck .
Dose the tank have a sender ? You could put a vent in it and bolt it back in.Or send a hose down the filler neck with a float on the end.
I added a metal tube in my filler tube. The new tube is just big enough to allow the gas pump nozzle in. This leaves the rest of the original tube as an air vent. The new tube curves upward to the top of the tank. works Great!
If I'm reading this correctly, I think the 90 degree bend is the problem. You say you raised the tank 2'' and had to use a 90 bend. The bend is filling with gas and then kicking back when the vapors from the tank have no place to go. If you can, use a 45 or 30 degree bend so the gas can flow into the tank and vent back out over the top of the incoming gasoline.
I told you that 90 would be a problem... I have the same issue in my '54 Chevy truck. It came with a vent in the filler neck, but I still have to turn the nozzle upside down and set it on slow to fill it. r
Just light up a match and burn the fumes as they escape! Problem solved. Heres your sign. This is just a joke. Dont try this at home.
I had the same issue on my 66 Mustang. The fix was to add a 3/8" vent line from the top of the tank to near the top of the filler neck. That allows air, fumes, and pressure somewhere to go when the gas gets to the top of the tank instead of "burping" back at you. You'll notice that most new cars have that extra hose near the top of the filler tube to do the same. Since I was working with a new tank, it was easy to add the extra fitting to the tank, but you might be able to punch, thread, and seal a fitting into a used tank.
Thanks thanks alot Rob... LOL Thanks for all the info boys Look like I am going to try a vent.. Stupid question but since my filler is so big could I just run a 3/8 hose down the neck to make a temp. vent line???
i think i have seen vent tubes on the inside of filler pipes, to try it out you could just hold a piece of 3/8" copper tube inside the filler so the end was near the top of the tank.
This may sound crazy but i look at the pump at how many gallons are going in and i know when to start goin slow, i fuck up and spill gas sometimes, i fuel up before dates too.
Had the same problem with my 40 chevy. I have a stock tank. I removed the filler tube and welded a 1/4 inch bung in it near the top. Next install a check valve in the bung. You may need a 45 or a 90 degree fitting to keep the check valve vertical. No problems now.
Getting gas is a pain in my ASS!! Uh, you shouldn't be sticking the nozzle in there Sorry, couldn't resist My Falcon had the same problem, Turns out the filler neck was too horizontal for the flow rate of the current pumps. I made a new neck that flows straight down into the tank instead of through the back panel, no more problems. Non vented cap is in the trunk and the vent hose is stock outside the trunk. Works fine.
I had the same problem with my 64 GMC. I didn't even think of adding a vent, so that the best way. In the mean time what I did was find the nearest gas station with a "collar" filler. The collar won't allow gas to flow through the nozel until the the collar has been pushed back against the filler about 1 1/2". I'm sure that this is so that you can't spray gas without having the filler in the car but it's also the best vent you can get. I wore a lot of gas on my shirts and even my face a few times until I found this out but now it works every time. I know that Safeway gas stations have them as well as most AMPM stations. Ask any local biker where the stations are, we hate those things because you have to hold the collar back to see how much gas your putting in the tank. Hope this helps for the short term at least.
This might be an alternative to modifying anything. I was watching an episode of Two Guys garage and saw a product called the fuel bib. supposedly it absorbs gas so it don't run down the side of your car and you just throw it away when done. Their web site is: www.thefuelbib.com maybe worth a try?
I think the problem is combination of vent and not enough drop from the filler to the tank. Try parking on a angled pump where the filler is higher on that side of the car. If that helps, then the problem is you need the filler higher to enable the gas to flow down and not fill up the tube.
"just run a 3/8 hose down the neck to make a temp. vent line?" That would be easy enough to try at first. I'd think it would work. r
I have the same problem using a '85 Suburban tank in a '62 Chevy truck. The tank is vented. I believe my problem is two fold, the filler has a 90 degree bend and the vent is below gas cap level.
if you look at a modern car gas tank filler pipe they have a one way "flap" that gets folded down when you insert the nozzle. this makes the hole that the nozzle fit in a tighter fit, AND the steel around the flap stops gas SHOOTING out. I went to the junk yard and took a pipe cutter and cut the filler tube with "flapper" off of a newer style car. I have the filler pipe at home, I'm going to cut the pipe apart and remove the flap. I'm going to make an insert that will fit tightly inside of the original filler tube about two inches down,, just like a moder car.. basically I'm going to add a modern "flap" to my old car. this will stop the huge gush of gas, it is why they installed them on modern cars. even today, you will find a super fast pump that will make a new car overflow.. you may get a little trickle like in a new car but it will stop the HUGE amount.
here is some of the reasons why this should work... http://www.wonderquest.com/sleeping-birds-gas-nozzles-cold-hospitals.htm
Actually, they installed them in the '70s on cars intended for unleaded gasoline. The leaded gasoline nozzles were much bigger (like modern Diesel) and wouldn't fit in. This was so you couldn't put leaded gas into a car intended for unleaded and ruin the catalytic converter.
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