Gas smell
Safety Car
Joined: May 2001
Posts: 4,754
Likes: 1,643
From: Fairfax Virginia
It could be the standard gas boiling over as the Hot engine is starting to cool down after a ride in warm weather. Sometimes a good thermal spacer under the carburetor between the intake and the base of the carburetor really helps prevent the post shut down boil-over. I had the same problem on my 1968 C3 with its 427 when I first bought it. It only smelled like gas for a short while during cool down. It was worse on my 427 with the Quadrajet as the float adjustment was too high and this made it boil over even easier. When I switched to a Holley I used a spacer and never had the boil over action again.
If you are smelling gasoline "all the time" in your garage then you need to really look at your fuel system! Start at the fuel tank and follow the fuel lines forward all the way to the fuel pump and the carburetor.
One morning before going on a trip I found a "Pinhole" leak in my Fuel Supply line, it barely left a spot on the ground as it would evaporate very quickly. I wrapped it with a piece of a bicycle inner tube and a hose clamp on top and I had no more gasoline leak/smell until I fixed the fuel line "properly" by replacing it.
Best regards,
Chris
If you are smelling gasoline "all the time" in your garage then you need to really look at your fuel system! Start at the fuel tank and follow the fuel lines forward all the way to the fuel pump and the carburetor.
One morning before going on a trip I found a "Pinhole" leak in my Fuel Supply line, it barely left a spot on the ground as it would evaporate very quickly. I wrapped it with a piece of a bicycle inner tube and a hose clamp on top and I had no more gasoline leak/smell until I fixed the fuel line "properly" by replacing it.
Best regards,
Chris
Is my vette stock?? HAHA
Joined: Oct 2015
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From: Im not allowed to tell you
2020 C3 of the Year Finalist - Modified
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the 68 has a vented gas cap but I usually dont smell a strong odor of gas. Use a very bright flash light and you should be able to see any fuel leaks with damp or a shiny wet spots. you can climb underneath at the passenger side tail pipe and see the bottom of tank and the hoses coming out of it. You will have to lower the spare tire tub to get a full view of it. You should be able to get some fingers up there to see if its leaking there. Other than that check all the fittings but it just maybe that its a carbureted car and its just natural.
HOw long does it smell?
HOw long does it smell?
Race Director
Joined: May 2006
Posts: 18,710
Likes: 2,574
Another source of a gasoline leak is the cork gasket between the filler neck and tank.
If you fill the tank above the bottom of the neck and then look under the rubber splash shield you will see gasoline seeping if the gasket has failed.
If you fill the tank above the bottom of the neck and then look under the rubber splash shield you will see gasoline seeping if the gasket has failed.
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Melting Slicks
Joined: Sep 2006
Posts: 2,812
Likes: 469
From: Wichita Kansas
Does the smell eventually dissipate or does it persist? And is this something new or has it been doing it all along? My 72 did that after I first got it, i replaced the fuel separator and the line from it to the charcoal canister, as well as the canister and the gas cap. Took care of the problem. So something there that I did fixed it. Until many years later when my fuel pump developed a leak, you could see that around the seam of the fuel pump. I hope you can get this worked out. 
Thread Starter
Le Mans Master
Joined: Jun 2019
Posts: 5,453
Likes: 2,169
From: Loveland
Does the smell eventually dissipate or does it persist? And is this something new or has it been doing it all along? My 72 did that after I first got it, i replaced the fuel separator and the line from it to the charcoal canister, as well as the canister and the gas cap. Took care of the problem. So something there that I did fixed it. Until many years later when my fuel pump developed a leak, you could see that around the seam of the fuel pump. I hope you can get this worked out.
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,074
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From: US-PNW
It sounds (subjectively) normal. Out of curiosity, does it have the Holley carb with the external vent arm/stopper on the forward fuel bowl? If so, I'd guess that the heated fuel in the bowl is evaporating out the vent until it cools. Keep in mind that these were the days before much was known about the effects of venting hydrocarbons to the atmosphere. Compared to today's engines, these are horrendously "dirty" engines.
Thread Starter
Le Mans Master
Joined: Jun 2019
Posts: 5,453
Likes: 2,169
From: Loveland
It sounds (subjectively) normal. Out of curiosity, does it have the Holley carb with the external vent arm/stopper on the forward fuel bowl? If so, I'd guess that the heated fuel in the bowl is evaporating out the vent until it cools. Keep in mind that these were the days before much was known about the effects of venting hydrocarbons to the atmosphere. Compared to today's engines, these are horrendously "dirty" engines.
Last edited by kodpkd; Apr 11, 2022 at 12:27 PM.
Race Director
Joined: May 2006
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Thread Starter
Le Mans Master
Joined: Jun 2019
Posts: 5,453
Likes: 2,169
From: Loveland
Thread Starter
Le Mans Master
Joined: Jun 2019
Posts: 5,453
Likes: 2,169
From: Loveland
In researching the 68 327, I found that the air cleaner housing is vented to the right side valve cover. The air cleaner is originally an open 360* filter.
Mine doesn't have that vent tube to the RT valve cover. Hummm, another thing to fix.
This could be the source of the smell.
It wasn't long after 68 that they went to a closed air filter housing. Maybe it was because of the vapor leaking out.
Mine doesn't have that vent tube to the RT valve cover. Hummm, another thing to fix.
This could be the source of the smell.
It wasn't long after 68 that they went to a closed air filter housing. Maybe it was because of the vapor leaking out.
Last edited by kodpkd; Apr 11, 2022 at 01:14 PM.
Drifting
Joined: Oct 2020
Posts: 1,566
Likes: 574
From: Wisconsin
My '71 smelled all the time in the garage when I first got it. It had a "vented" gas cap in that the P.O. had lost the gasket and it fit super loose.
I replaced the cap with a non vented one so the fuel separator and the charcoal canister could do it's job, and problem solved.
I don't recall if '68's had the fuel separator/canister. I don't think they did, so a vented cap is necessary.
I replaced the cap with a non vented one so the fuel separator and the charcoal canister could do it's job, and problem solved.
I don't recall if '68's had the fuel separator/canister. I don't think they did, so a vented cap is necessary.
Race Director
Joined: Sep 2001
Posts: 10,560
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From: Wellington, FL
St. Jude Donor '11 thru '25
In researching the 68 327, I found that the air cleaner housing is vented to the right side valve cover. The air cleaner is originally an open 360* filter.
Mine doesn't have that vent tube to the RT valve cover. Hummm, another thing to fix.
This could be the source of the smell.
It wasn't long after 68 that they went to a closed air filter housing. Maybe it was because of the vapor leaking out.
Mine doesn't have that vent tube to the RT valve cover. Hummm, another thing to fix.
This could be the source of the smell.
It wasn't long after 68 that they went to a closed air filter housing. Maybe it was because of the vapor leaking out.
Race Director
Joined: May 2006
Posts: 18,710
Likes: 2,574
In researching the 68 327, I found that the air cleaner housing is vented to the right side valve cover. The air cleaner is originally an open 360* filter.
Mine doesn't have that vent tube to the RT valve cover. Hummm, another thing to fix.
This could be the source of the smell.
It wasn't long after 68 that they went to a closed air filter housing. Maybe it was because of the vapor leaking out.
Mine doesn't have that vent tube to the RT valve cover. Hummm, another thing to fix.
This could be the source of the smell.
It wasn't long after 68 that they went to a closed air filter housing. Maybe it was because of the vapor leaking out.
Do you have any kind of breather on the passenger side valve cover?