Thread: Gasoline odor

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This is really strange. After reading the entire thread I can't imagine what would make fumes like that. We had 3 of our cars sitting in the shop with fuel in the tanks and never get any hint of gas odor. We even have one open jerry can that Dan has been using to draw gas out of for his RPU and no fumes from that one either.

My 23 just had a simple vented cap,and my 27 and Dons T have simple hose loops out of the tank vents. Very strange that you are having that issue.

Don

Originally Posted by Itoldyouso

This is really strange. After reading the entire thread I can't imagine what would make fumes like that. We had 3 of our cars sitting in the shop with fuel in the tanks and never get any hint of gas odor. We even have one open jerry can that Dan has been using to draw gas out of for his RPU and no fumes from that one either.

My 23 just had a simple vented cap,and my 27 and Dons T have simple hose loops out of the tank vents. Very strange that you are having that issue.

Don

Don - that vented gas cap may be what I need to install. I shouldn't need one with the rollover valve, but that's about the only thing I haven't done since I don't have a spare plus I really don't want gas to slop on my nicely painted '32 style gas tank (it's a '71 Jimmie cap, I believe that Tanks supplies)

I never had a problem with my '23 either and that only had a roll over valve and an unvented early Jag(?) flip open cap.

Originally Posted by Louey

Have you thought about using a small charcoal canister ? To store the fumes, until you start, and run the engine ?

I still can't understand why any of that would be necessary. On our stuff we are running nothing special, just looped hose or not even that, just vented caps, and not a whiff of odor. Something is odd with this one IMO, maybe that rollover thingie is doing something strange. I could stand right behind any of our cars and even remove the caps and get no smell.

Don

Just a thought, maybe the heat from the exhaust is just enough to expand the gas to start a siphoning cycle, its happened on my `64 pu, with the tank in the cab, on a real hot day, pushed the gas right past the cap and ran back down the filler tube into the cab, it was bad for a week...

Could it be that with a vented cap the odours are released slowly but with a non vented cap pressure builds up and then releases quickly make the odour more pronounced ??? just an idea

Steve - that's a thought as well, but until I get a spare 'petrol' cap am not going to start drilling holes yet.

I just went through my partially replumbed gas line and no leaks. Interesting that the Edelbrock carb seemed to have a slight gas odor around it so I did snug the input fuel line just a tad - but it does make me wonder about the carb itself. This is/was a brand new carb and all of the settings were checked when I originally set it up identical to an earlier carb that was on a 351W. I don't have a pressure regulator on it, but possibly it needs one as I have no idea what my fuel pressure is except that the Carter mechanical fuel pump was supposed to be the 6psig version - (hmmmm more AN fittings) The gas cap was loose so that might account for some odor. That cap does have a check valve to allow air in, but not out.

Oh well - gonna reset the coil overs and shock adjustments as I've procrastinated long enough about crawling under the car.

I just talked to Lee at Tanks, Inc and learned a few things. First, my billet cap did not have the thick o-ring gasket, so my odor in the trunk is most likely due to my cap not being sealed. Tanks is sending me an O-ring which they say is very thick and heavy, rated for fuel service.

Second, their brass anti-rollover valve actually is designed to fit down into the tank as it has two check balls - one is phenolic and floats up to seal the vent with slosh with a full tank (not supposed to be topped off, but if it is...), and the second is stainless to drop down if the tank/valve becomes inverted. Mounting it extended above the tank is fine, but Tanks does not consider that to be necessary with their dual check ball design.

Lee says that it is normal and expected to have a slight gas odor from the vent in a closed garage, especially as the tank warms as ambient temperatures increase since our applications do not have the modern OEM vapor recovery systems and charcoal filters.

Hopefully the O-ring gets rid of a lot of my gas aroma, and I am still going to get a longer hose for a up & down loop seal.

Originally Posted by rspears

I just talked to Lee at Tanks, Inc and learned a few things. First, my billet cap did not have the thick o-ring gasket, so my odor in the trunk is most likely due to my cap not being sealed. Tanks is sending me an O-ring which they say is very thick and heavy, rated for fuel service.

Second, their brass anti-rollover valve actually is designed to fit down into the tank as it has two check balls - one is phenolic and floats up to seal the vent with slosh with a full tank (not supposed to be topped off, but if it is...), and the second is stainless to drop down if the tank/valve becomes inverted. Mounting it extended above the tank is fine, but Tanks does not consider that to be necessary with their dual check ball design.

Hopefully the O-ring gets rid of a lot of my gas aroma, and I am still going to get a longer hose for a up & down loop seal.

I used this same valve and have it mounted externally on a short section of hose. No loops in the line and no odors found. I also have the aluminum cap with the heavy o-ring on a steel neck and haven't had any problems. I also apply never-sieze out of habit!