1960 Buick gas cap---Vented???

[Dave@Moon]

I recently changed the gas cap on my 1960 LeSabre to a NORS replacement cap. (The car originally came with a factory locking cap that I'm saving for show.) The cap is marked "Not Vented". <P>Since I installed the cap, I've noticed a strong gas odor that comes from the car about every 10-15 miles of driving. I cannot pinpoint the source of the smell. There's no dripping or obvious leak that I can identify. There is only a slight staining of the carb (Stromberg 2 brl.) from vapor leakage at the vent, which is normal (at least compared to how the car was running before). <P>This is the car I installed an electric fuel pump on in 1997 because of gas boiling in the carb at shutoff. However, when the odor occurs the carb appears dry, with none of the dripping that I noticed previously. <P>Once, when i was trying to trace the source of the smell, I noticed a small bubbling sound coming from the rubber vent line next to the gas cap. when I opened the unvented cap, the bubbling ceased and the odor dissapated (which it does on it's own eventually anyway). <P>Th odor is apparrent while driving or while sitting. Turning the car (and/or the fuel pump) off doesn't affect the odor either way. <P>Is the gas cap on a 1960 car supposed to be vented or non-vented? Would this cause an intermittant odor problem? How?

[Guest]

My dad told me a story about installing a non-vented cap on his '54 Studebaker. He almost got hit by a semi when he pulled into an intersection and the car sputtered like it was out of gas. The gauge read half a tank. He opened the gas cap and heard a loud FOOM! As the car used up its gas it had no air to replace the space used up by that gas. This created a vacuum that sucked the tank in till it hit the sending unit and made it read half-full. When he opened the cap the tank returned to its normal shape, really fast.<P>The only cars that I know of that use non-vented caps are cars with charcoal canisters. Otherwise it needs a way for air to get into the tank.<P>Hope this helps,<BR>Tom

[Dave@Moon]

Thanks Tom.<P>Like I said, though, there is a rubber vent line to the tank by the gas cap. So a vented cap <I> might </I> not be neccessary. My question is if this is a correct or incorrect assumption. The factory locking cap I replaced wasn't marked, but appeared to be anything but airtight.<P>Any ideas?

[Guest oldtimer]

i have a '60 el camino and the cap on it is vented and my stant book calls for vented. the vent tube you see goes from the tank side or top to just under the cap, but it still needs to be vented out through the cap.