Need gas cap ideas.

So this is a standard 1966 Mustang tail light panel(not my car, just a google search result):

I was not happy with the factory look, mainly due to the unsightly gaps around the ends of the panel and the bevel below it(and I ust didnt like the tail lights), so I took inspiration from the 1966 prototype car(which never made it to production):

For the prototype car, Ford did a lot better of a job coming up with a more finished looking tail light panel, so I decided to essentially copy what Ford did, I drew up my own tail light bezels and had an online machine shop cut them, while I am waiting for them to come in, I decided to modify my tail light panel in a similar fashion:

Now you might notice, as part of the design I added a crease(slightly more prominent than the one Ford used back on the prototype in 1966), but if you look closely at the prototype picture you will notice that the shadow around the gas cap is heavier on the top and bottom, which means that the gas cap is sitting farther away from the panel than a production 1966 mustang...and the cap sits 1/4" away already on a perfectly flat panel. So this leaves me with the conundrum of what to do for a gas cap. I can't use a stock gas cap without it looking pretty bad. I might be able to scribe and contour a pop-open gas cap to follow the crease, but pop-open type caps are a bit bulkier than I like. Anyone have any clean solutions? I am tempted to just have a fill-tube in the trunk and leave it shaved, but I am not sure whether spills would happen often enough to make that just a really bad idea. Maybe someone makes a twist-in type filler neck that I can disconnect when not needed? I am considering a flush-mount type cap, but considering the only part of it that would be flush would be at the peak of the crease I am just not sure how that would look.

Go to the 1:25 mark

https://www.youtube.com/watch?v=OgwtpS3bELc 

Its too bad you already made the tail-lights.  You could make one of them slide to the side or swing open in order to put the gas cap behind it.  

Yeah, some old 50s car had swing away lights...but this style doesn't lend itself well to that. As far as mounting it on the top of the 1/4 panel that would have essentially the same issue as the tail light panel except in reverse, since its concave. My old '75 trans am had the filler hidden behind the license plate, but the plate is too low for that to work here.

I've always like the tail lights on the 1966 prototype and I like what you're doing here.

I bought my first '65 Mustang in 1983. I prefer the 1965 gas cap to the 1966. But around that time, I read an article in Mustang Monthly magazine about another prototype that Ford had made for the movie Goldfinger. It was a fastback and I don't remember all the details, but if I recall correctly it wasn't ready in time for filming and it didn't make the cut. 

Anyway, that car had a special gas cap, made out of the spinner from an optional 1965 hubcap.

I had an extra set of spinner hubcaps at the time, so I removed one of the spinners (three screws) and picked up a '66 gas cap. I drilled out the rivets that held the decorative cover to the business end of the cap and then attached the spinner to that. I needed a spacer (1/4" or so) to fill the gap between the base and the panel. I didn't love the look, as I thought that the diameter of the spinner was a little large for the height of the panel, but I had it on my car for a little while.

I don't know if this would be a look that you would be after, but it would have some historical context to go along with your prototype tail lights. I think you might need a 3D printed V spacer between the filler neck and your new panel to make the transition from bent to flat, and then another small spacer to fill the gap between the edge of the spacer and the spinner.

These are not photos of the one that I made, but this is the car that inspired it.

I didn't have a photo from this angle when I built mine (in fact, this is the first time I've ever seen it), but from this modern photo of the car, it looks like they just mounted a spinner directly to an original '65 gas cap. Had I seen this at the time, this is how I would have done it. It would have actually been easier and better looking.

This is the only photo that I had to work from in 1983, so I wasn't able to see the side profile of what was probably a full '65 cap used as a base. If I had grabbed a spare '65 cap instead of a '66 cap, my high school brain might have been able to figure out how they had made the original.

The proportions of the cap look a little better from this angle.

In reply to Mr_Asa :

There's too much space there to not have something in the middle of that panel.

Also, a side mounted filler opening wouldn't work well with an unmodified tank. it would really intrude on the trunk space.

So...this is funny. I did a little more digging, and the first photos that I ever saw of the Mustang 007 were in the May 1982 issue of Mustang Monthly (I still have it!), and the first photo that I ever saw of the 1966 prototype was on the same page of the same issue!

(Crappy photo)

And...my apologies for the threadjack.

Just throwing out an idea here:

French something like this in. I like simple lines. Make the radius +1" so you can get your fingers in there to open it?

Same idea with something like this?

More inspiration, but you are obviously not on such a curved surface.

I think something rectangular would look better there.  Perhaps some variation of the horse in the corral that's on the grill on a flip down panel?

In reply to Woody (Forum Supportum) :

Interesting, never seen that one before...but sticks out too much for my taste.(I could likely duplicate it though, I don't have original spinners, but I have some from some 05 v6 wheels that are a touch smaller).

If you don't like the looks of a traditionally sized gas cap door in the middle, maybe make the entire panel between the lights fold down.   The seam at the inboard lights might not be seen

APEowner said:

I think something rectangular would look better there.  Perhaps some variation of the horse in the corral that's on the grill on a flip down panel?

An interesting idea...but considering I am keeping the car completely debadged(Ford has made a lot of decisions over the last few decades that annoy me, so its my way of protesting) That won't quite work either. I am looking at a number of different caps like this:

This one is actually a Harley cap, but its very low profile and seems pretty nice(who knows what size it is though?)

A wide variety of caps similar to this type(varying the number of bolts, color, etc)

Another motorcyle cap, but appealing since its 5 bolt just like the original mustang flange(probably not the same centering though)

In think that the central round gas cap was a definitive feature of the early Mustang design. The car almost demands it. 
 

There's an early Mustang around here that has '67 Firebird tail lights with a square gas door in the center. I don't love it, but in this case, the square door (kinda) works with the parallel light bars. Doesn't really suit the car though. It's an unholy matrimony. 

I like a lot of the ideas being thrown around for the panel, but if you want an in trunk setup you could adapt something like this one designed for Bmw 2002s

Woody (Forum Supportum) said:

In reply to Mr_Asa :

There's too much space there to not have something in the middle of that panel.

Also, a side mounted filler opening wouldn't work well with an unmodified tank. it would really intrude on the trunk space.

It does need something in the middle (maybe) but I'm not convinced a gas cap is what's needed.

Wicked93gs said:

APEowner said:

I think something rectangular would look better there.  Perhaps some variation of the horse in the corral that's on the grill on a flip down panel?

An interesting idea...but considering I am keeping the car completely debadged(Ford has made a lot of decisions over the last few decades that annoy me, so its my way of protesting) That won't quite work either. I am looking at a number of different caps like this:

This one is actually a Harley cap, but its very low profile and seems pretty nice(who knows what size it is though?)

A wide variety of caps similar to this type(varying the number of bolts, color, etc)

Another motorcyle cap, but appealing since its 5 bolt just like the original mustang flange(probably not the same centering though)

I like the cap on the bottom.  I wouldn't put the filler in the trunk, I had a car like that and I didn't have many spills but when I did it was around something it shouldn't have been. 

I'm thinking a motorcycle gas cap, but not the modern style in the previous post - something simple and round, like you'd see on a mid-60s British bike.   Here's one example: https://www.lowbrowcustoms.com/products/british-standard-triumph-bsa-british-motorcycle-gas-cap-made-in-the-uk

Simulated what a 3" cap would look like(think this is an old horn button or something, but it works). Somehow even at 3/4" it feels kinda bulky.

And just for giggles the modern-day spinner I had on the shelf. (Hey, I have to do something while stitch welding the top of the panel while each set of stitches cools, already managed to warp this panel once so I had to fix it.)

Zoom in on the rear quarter:

Best image I could find. It's in a Vice Grip Garage video on You tube if you are at all interested.

In reply to wheelsmithy (Joe-with-an-L) :

Those would be a lot more appealing if they didn't have so many bolt holes(and if they were countersunk). I mean...a flywheel has fewer bolts. I do actually like that design, but in the end I think I am going for this type:

For 2 reasons really: 1. Its as low profile as you can get. 2. A cap that unscrews is better for a vertical panel than one that pops open...pop-open will only end up being a frustration every time you fill up by making you hold up the cap to get the pump in, or alternatively have to angle the pump handle. I do still have some time to decide, but I got a start on modifying the panel to have a flat spot to work with:

I guess its an inversion of what Ford did for the '67 anyway:

I guess I can take a bit of comfort knowing that what Ford had to do with the '67 is much more visually impactful than what I had to do.

How would it look if the space for the cap was recessed (frenched) into the panel, rather than having it stand proud?  It appears you have the metalworking skills to do so.

stuart in mn said:

How would it look if the space for the cap was recessed (frenched) into the panel, rather than having it stand proud?  It appears you have the metalworking skills to do so.

I considered doing that, but in the end the edge of the cap(or the ring in the case of aircraft style fillers) would be partially flush with the panel and partially protruding So I think it would look bad(perfectly fine when the panel is flat) unless you recessed it past flush...but it would look just as bad that way. I think this way is the lesser of all the evils I have the option of doing. Even sitting on a flat like this, the low profile of the aircraft type filler will end up lower key than the stock gas cap