The vent on my early '26 roadster is about to be installed. I have what I thought were the original screws but they just don't seem to fit properly. They are (I think) 10-32 flat head machine screws. There doesn't seem to be any accommodation for them to be countersunk. Anyone out there have any idea how it should be attached?
The fuel door lid is held with those oval head machine screws from above, lock washers and square nuts below. Don't know why the holes aren't countersunk for them, but the holes are straight, head sticks up a tiny bit, but won't interfere with action of the lid.
Oval head and not flat head-is that correct?
The ones I found on my 27 Roadster are round head type, but they don't look too convincing.
I'll find some oval head screws for the reassembly. That should help to center things up better too.
Oops. Sorry guys. I made a bad.
That screw is a flat head single slot.
Guess I need to look first before just remembering.
Here is the correct original fastener for that fuel door lid.
Still can't get it right, its a low, shallow round head, not really flat.
Perhaps this is a good place to talk about the various stops the fuel door lid has depending on when it was made??
Yes, your looks like it has a rounded head, Mine is definitely flat. I can't show you an image because it is back in the shop and I won't be there until monday, My car was built in October of '25, so who knows what they had on hand then. It Just doesn't look right because the head sticks up above the surface. If I could find screw like yours I would use them.
Arnie, what do you mean by stops?
I think he is referring to the two "stops" in the gas door spring that holds the door partially open for ventilation or fully open for refueling.
IIRC the one shown in Dan's picture is called "button head".
I believe the screw in Dan's photo is a Truss Head.
Larry has it right. They're called a Truss Head screw.
When you know the correct name of a fastener, it makes it much easier to find the right one.
Yes, I was referring to the one, two or possibly (?) three stops in the gas door spring. This might be a change in the 26/27 gas door spring design. Does anyone have a 3 position gas door?? We could try to see just when the change took place as it is easy for members to lift the gas door to determine the answer.
They may be called truss head bolts, but they are commonly referred to as gutter bolts in Australia. They are typically used when bolting together sheet metal, the larger flatter head used in conjunction with a square half nut. I have only ever seen them in 3/16" and 1/4" coarse thread.
Just for interest.
Allan from down under.
Here are the screws that came from my vent lid. As you see they are flat head.
I stand corrected.
My September 1926 production roadster had round or truss head screws when I removed the fuel door. They are at the painter's now so I can't get a better picture at the moment.
The door has two positions not counting closed (horizontal).
Picked up two truss head screws at a local hardware store today They are 8x32. I'm a happy camper. I think my lid only has two stops-open and closed but I am not sure as the body is at the shop and I can't compare it with Eric's pictures. Glad to see that the gas tank was originally painted black as was mine.