Gunk in '25 Dodge gas tank

[Pete K.]

Well, it seems these days, everybody that has a 1920's Dodge is pulling off their fuel tanks for clean out and repairs. This now includes me, which was on my recent find near my home, the '25 touring. I knew there wasn't much of any fuel in the tank, that I could determine and I felt very lucky that the drain screw came out OK, it's a 3/8" hex head, and found it to be a steel tapered plug. When I removed it, only a slight drip - drip --- SO.. I took a nail to the tiny opening, and GOOSH! The worst smelling, foul liquid spewed out, quickly filling the coffee can I had in my other hand. Back went the drain screw to halt Hell's Fluid, of course it went right down my arm and into my sweatshirt sleeve. Off to locate a bigger can! I was amazed that the tank strap nuts came loose so easy, I had sprayed the threads earlier with Liquid Wrench, still a long process with a 9/16" box wrench. Not enough room above the strap screws for a socket wrench. Got tank off car, with it laying on my belly, as I am on my back on floor, under car. I can see this will really be FUN putting this back in place! I will build a stand for this job. I removed the gauge bezel OK, out came the fuel sending unit, complete with original cork float, all rusted into one dark brown glob. The photo is of a "clear" plastic jar with some of the "fluid" (it's no longer gasoline)- that I drained out of tank. And this is held up to the light!!

[Machinist_Bill]

Don't ya just love that shellac smell? Take plenty of photos so it will talk me out of doing mine.....

Whenever I store my cars for long periods I run down to my closest small airport and get 5 gallons of airplane fuel. Shelf life is a lot longer. Shelf life of today's fuel is 90 days. Shelf life of airplane fuel "Used to be" 5 years.

[MikeC5]

You still had liquid in there!? Mine had dried into black, smelly chunks of carbon-laden stuff.

[Guest 1930]

Prob. sell it as moonshine

[Pete K.]

I don't mind the smell of shellac, or just about anything else in reason, but this stuff is THE WORST. Jason, I'd be shot if I tried to pass this off as "shine"--Here's a photo of the "real McCoy"--Note how it is crystal clear.I'm thinking of selling my copper still, Do you want a new vocation? I hear there's good money in it. Anyway, my gas tank is also full of chunks too, I'm trying to get time today to start the cleaning process. I'm not going to use a sealer at the end, albeit no pin holes, From what I'm reading here on the forum, I'm not sure what the future holds for other fuel additives that could destroy a sealer.

[karasmer]

I have been in the process of cleaning mine. I added a bunch of 1/2 inch sharp driveway rock, wood bleach (it has acid in it), and small amount of water. Shake well, let stand, and repeat untill clear water remains. Sure works great but you get sore arms from all the swishing and shaking

[Pete K.]

Thanks karasmer! That's exactly what I'll do. I do have some wood bleach here, they label it as "Oxalic acid".---Pete.

[Guest 1930]

Good money till you get caught

[MikeC5]

I had the engine running tonight on the vacuum tank and gas tank! I had tested the vacuum tank beforehand by sealing up all ports except the vacuum port which I hooked up my hand pump vacuum bleeder. After a few pumps it was able to hold a 10" vacuum well. This doesn't test the valves but it will reveal vacuum leaks.

One question: my fuel filter, cylindrical-horizontal, mounted inside the frame rail, didn't have very much gas in it (maybe the lower 1/4"). I mostly ran the engine at a fast idle. Is this normal?

[platt-deutsch]

Fuel Filter must have been added later. Mine only has a small screen in the fuel inlet port elbow at the vaccuum tank.

[MikeC5]

Yes this is a modern (see through) filter I put in the line.

[Pete K.]

Mike, Something's telling me your fuel level is OK in the in-line filter you've got. The original vacuum system probably only bleeds a small portion of engine vacuum to the Stewart tank, or rather the valve system in the Stewart tank is needing a portion of engine vacuum to trickle the fuel into vacuum tank as needed, thereby, system does not require a "return line" to rear tank. As long as your vacuum tank fills the lower chamber with fuel for the gravity portion of system to the carb, you're all set. I hope this explains why your in line filter is not filling all the way up.---Pete.

[MikeC5]

I think you are right Pete. I know it had to be working since I ran the engine for 20 minutes. It won't go that long on one vacuum tank's worth... I looked at the filter today and it was half full. I'll have to see if it stays that way when I fire it up again.

[1936 D2]

There was a discussion at length earlier on this Forum about visible in-line filters not filling up all the way. The consensus was that it is normal. Shouldn't be a problem.

[MikeC5]

I was running the engine today and after it warmed up it began missing. I know the valve clearances are not too tight (I purposely set them a bit large just for good measure). So it's sitting there idling and then I hear a 'poof' sound and dark grey smoke starts pouring out from under the exhaust manifold! I'm thinking cracked block? Well luckily it was only my (modern) coil blowing its top. I had the coil sitting in the open hole where the original coil would go and apparently the (taller) coil was a wee bit too close to the exhaust manifold. These coils are oil filled (I read somewhere) and this one looked to have a small plug on the top that acted as a relief valve. I'm pretty sure over-temping a coil doesn't do wonders for proper ignition. I'll have to find another place to mount it. Eventually I will have to fork over the $200 to get a rebuilt original coil though.