My neighbor just bought a 65 from a young guy that made some changes. The biggest being a fuel cell installed in the trunk. I tried to help him with it since it wasn't wired. We got the fuel gauge to work, but the gauge is not reading right. We filled the tank & the autometer gauge is only showing between 1/2 & 3/4. The other thing is the plumbing on the cell. There are 4 fittings on the fuel cell. 2 on the bottom & 2 on top. One of them on the bottom, I believe the one toward the front is hooked up to a fuel line. The other one is capped. The 2 on top has a rubber hose that goes from one fitting to the other. The 2 on top seem to be the most odd. It doesn't seem to be right. Why would you have a hose go from one to the other, if that is supposed to be right, couldn't you just cap the 2 fittings? Also, is there supposed to be a vent line? There is none & it sure is hard to pull the gas cap out. Seems there is pressure in the tank & when the cap finally pulls out the cell seems to suck in. My neighbor was told it came from Summit. Its there own brand with Gm sender. Any ideas esp the plumbing & venting?

I believe the one on bottom is for the fuel. Then the 2 on top are the vent and return line. They were probably just plugged together with a hose to keep dust out. So if you have efi/electric pump, you will want one as a return line, then just run the other as a vent. Im pretty sure thats how it is supposed to work.

Since it's carbureted I guess then it's correct? He said it drove fine, it just looks odd. I looked in the Summit catalog & I see none of the other cells have 2 fittings on top. Most have 1 or none. He has the satin one.

One of the top fittings should be used to vent gas fumes to outside the trunk area. Sometimes, the fitting will include a tip over check valve...mine does.

The two on the sump, (bottom) are for fuel. If you need to run parallel fuel systems, one nitrous and one for the motor, that's what they're for. If you have no nitrous, then cap one off and run engine fuel from the other one. The two on the top are like the other guys stated, one is for your roll over vent, and the other is for a return. If nothing else, plumb the vent to outside the trunk. NHRA says you gotta have a rear firewall between the passenger compartment and the trunk when you install a cell and trunk mount battery. I HIGHLY suggest you do that, too if it hasn't already been done. As for the gauge, if it has foam inside the tank (black sponge-like matirial) the float may be getting hung up on that.

Check out this pic, you can see the roll over vent, (hard line) return line, (braided line) and firewall.
http://i129.photobucket.com/albums/p224/earthquake68/100_0967.jpg

Another thing to consider, NHRA won't allow more then 12" of rubber line. Their rules are in place for a reason, to keep you from bursting into flames while driving your hotrod. I normally wouldn't preach so much, but anyone who ties the upper ports together deserves to have his work re-examined.:sad:

The two on the sump, (bottom) are for fuel. If you need to run parallel fuel systems, one nitrous and one for the motor, that's what they're for. If you have no nitrous, then cap one off and run engine fuel from the other one. The two on the top are like the other guys stated, one is for your roll over vent, and the other is for a return. If nothing else, plumb the vent to outside the trunk. NHRA says you gotta have a rear firewall between the passenger compartment and the trunk when you install a cell and trunk mount battery. I HIGHLY suggest you do that, too if it hasn't already been done. As for the gauge, if it has foam inside the tank (black sponge-like matirial) the float may be getting hung up on that.

Check out this pic, you can see the roll over vent, (hard line) return line, (braided line) and firewall.
http://i129.photobucket.com/albums/p224/earthquake68/100_0967.jpg

Another thing to consider, NHRA won't allow more then 12" of rubber line. Their rules are in place for a reason, to keep you from bursting into flames while driving your hotrod. I normally wouldn't preach so much, but anyone who ties the upper ports together deserves to have his work re-examined.:sad:

Thanks for the pic. I called my neighbor & told him to unhook the line & use one for the vent. He was actually told this by Summit when he called them about the fuel cell. They couldn't tell him which was the vent line though. I believe he said it didn't matter which one he used to vent. Just cap the other.
Summit also told him to vent the line higher than the cell? His looks like the pic & to have it go out the trunk I would think it would end up being lower than cell. Wouldn't it leak gas?
I printed this up to give to him as well. I don't know if there is a steel divider, but I assume there isn't based on how it was plumbed.

No, the vent goes up higher then the tank, then loops down so no amount of fuel slosh will leak gas onto the ground. The vent tube should actually end lower then the cell so if you do roll it, all the gas won't push out. Got it? I'm not sure I explained that clearly. Up far enough so gas won't slosh out, end low enough so if the car is upside down gas won't push out of the vent. Hence the name rollover vent. What the picture doesn't show is the vent tube goes through a grommeted hole in the trunk floor and ends two inches below the sump.

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