# Gas Cap Mystery



## Mosstone (4 mo ago)

Hey all. New member here... I have an old van that a previous owner had installed an additional gas inlet port in the side of. I don't know what it was intended for. It doesn't connect with anything. It's just a hole in the side of the van. I'd like to get a locking gas cap for it, just so nobody can shove anything unwanted into it from the outside, but I have no idea what cap to get for it. It's a Chevy Express cargo van, but the van's gas cap doesn't fit this inlet, so I can't just go on Amazon and order a cap for a Chevy Express. The diameter of the opening is about 2", but it's impossible to find a gas cap armed with that information alone, so I was hoping someone out on the web might have a clue.

Any educated guesses would be appreciated. Thanks in advance!

Here's a pic:


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## Steve2444 (Sep 28, 2020)

Moonshine?
Un-educated guess


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## Old Thomas (Nov 28, 2019)

A second gas tank that never got installed?


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## Msradell (Sep 1, 2011)

Just go to a local auto parts store and have them look at it, I'm sure they have a gas that will fit!


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## chandler48 (Jun 5, 2017)

Looks like the one on my '55 Ford 640 tractor would fit, but it isn't locking.


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## Nealtw (Jun 22, 2017)

BrassCraft BC7120-SS 2-Inch Sink Hole Cover (PVD Stainless Steel) : Amazon.ca: Tools & Home Improvement


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## Marq1 (May 31, 2021)

Unbolt it, cut a round piece of metal, reinstall, done!


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## Mosstone (4 mo ago)

Steve2444 said:


> Moonshine?
> Un-educated guess


Haha... Maybe if this van were 100 years old. 



Old Thomas said:


> A second gas tank that never got installed?


A previous owner had made a pretty crude attempt to convert this into a camper van (which is my goal as well), so my guess is that it was intended as a water inlet? but who knows? It could have been installed at any time in the last 21 years. 



Nealtw said:


> BrassCraft BC7120-SS 2-Inch Sink Hole Cover (PVD Stainless Steel) : Amazon.ca: Tools & Home Improvement


That's actually not a bad idea. Thanks!



Marq1 said:


> Unbolt it, cut a round piece of metal, reinstall, done!


That sounds an awful lot like work, and I've got plenty of that to do on this van already. 
The person who previously did (or _started_) the conversion work on this van had some rather... unorthodox ideas. Just undoing all this Mickey Mouse construction has turned into a major undertaking. Things that seem simple to dismantle on the surface turn into a three-day nightmare, because apparently, slathering everything with epoxy (including all the screws and bolts) and calling it good is an accepted construction technique. I can tell by looking at the other side of that inlet that it won't be quite as easy as simply unscrewing the bolts and pulling the unit out.

The other thing is; I'm not sure if I want to permanently cover that opening. I had considered just shoving a plug in there and calling it a day, but I can't help but thinking I may find a use for that in the future. For what? I have no idea, but I'm always a little hesitant to make irreversible mods. At the very least, it does provide ventilation. When I have the ceiling fan pulling air out, I can feel a nice breeze coming in through that pipe. 

Thanks for all your responses, guys!


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## KennyKK (4 mo ago)

Mosstone said:


> Hey all. New member here... I have an old van that a previous owner had installed an additional gas inlet port in the side of. I don't know what it was intended for. It doesn't connect with anything. It's just a hole in the side of the van. I'd like to get a locking gas cap for it, just so nobody can shove anything unwanted into it from the outside, but I have no idea what cap to get for it. It's a Chevy Express cargo van, but the van's gas cap doesn't fit this inlet, so I can't just go on Amazon and order a cap for a Chevy Express. The diameter of the opening is about 2", but it's impossible to find a gas cap armed with that information alone, so I was hoping someone out on the web might have a clue.
> 
> Any educated guesses would be appreciated. Thanks in advance!
> 
> ...


How big is the hole diameter? My friend has a propane-powered car and the hole itself is very similar, so a second gas tank guess might be a good one.


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## Jeekinz (Jan 29, 2007)

Go to an actual auto parts store. There's more to life than Amazon. lol


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## Mosstone (4 mo ago)

Jeekinz said:


> Go to an actual auto parts store. There's more to life than Amazon. lol


Hey man... Don't judge me because my time is valuable to me.  An auto parts store is the only place in the world where you can wait in line for half an hour to buy a bottle of Scratch-X, with only TWO people ahead of you in line, because the clerk apparently went to Detroit to find a starter for a 2012 Caravan for the guy at the register.

To be honest, whenever I look at my email I feel mildly ashamed of the number of purchases I've made for this project on Amazon, but I'm already spending enough time (and gas) making trips to fetch lumber, building materials and all the other sundry items that you just _have_ to go to a brick and mortar for (sometimes it feels like I spend more time wandering around Home Depot than working on the van), and around here (San Fernando Valley), every trip is a long trip... Even if it's just a few miles away. So the fewer unnecessary trips I can take, the better.


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## Mosstone (4 mo ago)

KennyKK said:


> How big is the hole diameter? My friend has a propane-powered car and the hole itself is very similar, so a second gas tank guess might be a good one.



The opening is 2" in diameter. I can't rule out that it was intended for some alternate fuel tank, it's just that it's pretty clear that the guy who did the work on this van was NOT handy, so the thought of him rigging this thing up to run on bio-fuel or something seems unlikely. Also, if it was intended to connect to a tank, it would have to be _inside_ the van. The pipe comes in about 10" above the floor, and is about 4" or 5" long.


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## chandler48 (Jun 5, 2017)

It was just an add on fuel tank, sort of like a "reserve", as it appears too small for long distance. What is it that you want to do?


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## 3onthetree (Dec 7, 2018)

I'd say that is an older gas cap tank bung, so find a steel motorcycle/non-auto engine gas cap that fits. Don't think box stores sell them, maybe a TSC or Farm&Fleet if you have those near you. So you can use Amazon if they list dimensions - look up "cam style gap cap."


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## Mike Milam (Mar 3, 2017)

While there are other places than Amazon, I found this, and it appears that it will work.

Amazon.com: Gates 31770 Locking Fuel Tank Cap : Automotive


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## Matt1963 (5 mo ago)

Mike Milam said:


> While there are other places than Amazon, I found this, and it appears that it will work.
> 
> Amazon.com: Gates 31770 Locking Fuel Tank Cap : Automotive


If you aren't going to use it get rid of it. (Patch)

Or if your going to install a water tank or something replace it with something from a marine store.


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## KennyKK (4 mo ago)

Mosstone said:


> The opening is 2" in diameter. I can't rule out that it was intended for some alternate fuel tank, it's just that it's pretty clear that the guy who did the work on this van was NOT handy, so the thought of him rigging this thing up to run on bio-fuel or something seems unlikely. Also, if it was intended to connect to a tank, it would have to be _inside_ the van. The pipe comes in about 10" above the floor, and is about 4" or 5" long.
> 
> View attachment 713181
> 
> ...


Thanks for the details. You're right, it doesn't look very neat from the inside. I think that if it is possible to use it as a reservoir for water, then this can be useful.


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