The gas cap on my 53 isn't vented. It looks like the big brother of the cap on my 38's road draft tube. I have no idea if it's the OEM cap or not. I've had no issues with driveability because it's not vented which makes we wonder how the tank is vented?
VCCA Member 43216 Save a life, adopt a senior shelter pet. 1938 HB Business Coupe 1953 210 Sedan
Mystery solved. The cap isn't vented. Ecklers says there's a "slit" in the filler neck for venting. I took a look this morning and snapped some pics. It took me a while to find the "slit" in the neck. I'd call it a "notch" instead. In the picture of the neck look at the 12 o'clock position. You'll see a small notch in the rim that acts as the vent.
VCCA Member 43216 Save a life, adopt a senior shelter pet. 1938 HB Business Coupe 1953 210 Sedan
I stopped to get gas a few days ago and when I removed the cab I got a sudden rush of air from the tank. This is after the car had been driven several miles on a really warm day. I had never noticed this before.
1951 styline deluxe sport coupe w/54 engine and power glide
Check the cap or tank vent as it likely is plugged. There should be a vent on the tank to equalize pressure inside and out. Otherwise there is a likelyhood of partially collapsing the tank or restricting the flow to the carburetor.
This is a response to Pidlar’s post. Most of the gas caps that are sold as “retrofit” for these older cars are not true reproductions. Most of them have spring loaded either vacuum or pressure or maybe both relief valves. The original gas caps did not have those.
I think I have 3 or 4 replacement fuel caps I have bought over the years for my ”˜37. The one on the car when I bought it did not seal adequately so gas would spill out the filler when the tank was even 3/4 full. Currently I have one that seems to work fairly well. It does get a slight pressure build up on hot days but it seems to work ok to prevent a vacuum problem. As Chipper noted that can cause lots of issues.
