VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 Contaminated gas at the carburetor

Apologies up front for the length of this thread, but I don't know which part of the history is relevant. After bending a couple of pushrods and failing to successfully free my valves with the head still on, I pulled it off. The machine shop was able to grind the seats and the valves, they were impressed with the condition of such old, original parts, so needless to say I was happy. Anyway, fully refurbished head back on, manifolds in place, newly rebuilt carb installed, new gaskets all around, everything was as it should be. Lashed the valves, checked compression, everything is in order. Did it start? No.

I'll skip the details in between, but when I pulled the gas line from the carb and gave it a couple of cranks, these pictures are what shot out (the pictures are after it settled and separated). My first thought was "Well crap how did that rusty water get in my tank?" Put a bucket under the gas line at the tank and drained some, the gas was as clear and fresh as when I pumped it. I guess I must have fudged the head gasket, better have a look at the coolant even though it couldn't have gotten that dirty just sitting there in such a short time, but it too looks as fresh and clean as new. I know that oil won't separate from gas, but better have a look at that, too. Nope.

So, somewhere between the gas tank and the carburetor, filthy water is getting mixed with my gas. It HAS to be at the fuel pump, there is no other possible source. Still, before I start pulling things apart I figured I would ask the experts. Anyone ever come across anything like this before?

I am sorry if I missed it or it is a dumb question but did you drain and clean the fuel tank?

Dave

If you still have a sediment bowl fuel pump is the gas in it clear? The steps I would take is to remove all of the fuel from the gas tank and inspect the tank and fuel. If that checks good, pour the gas back into the tank and pull the inlet at the pump and see what drains out. Follow each connection forward to the carburetor until you find the contaminant. A bad head gasket would do nothing to put watery gas in your fuel pump since there's no connection between the two. I suspect it's a problem with your tank. The steps above will verify or eliminate that.

I didn't drain the tank completely, but it sounds like good advice so I'll give it a go. Tiny, there was some of the same dirty water in the bowl at the pump, I've cleaned it all up already. Once I have the tank clean, I'll put a new carb on and see what comes next. Thanks everyone.

. When resurrecting a vehicle that has been sitting for years, I would recommend cleaning and coating the fuel tank. When blowing the lines, if rusty water comes out, the lines may be almost rusted thru from the inside. The steel lines used in a 1937 can be replaced with steel brake lines of same size. After you make sure your Fuel Pump and Carburetor are clean, install a glass bowl fuel filter just before the Carb. This will run into the horn if you have a Rochester Carb. The modern plastic inline filters will remove crumbs from the line but the glass bowl removes water that comes from condensation formed when a vehicle sits for extended periods of time. The AC with ceramic filter were original but after market with paper filters work well. .
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Gas with ethonol does that. Did it have fresh gasoline? Maybe the station had water in the tanks also.

Looks and Smell are two different things.
I use nothing but non ethanal gas, I use gas stabilizer at the end of the year and drain all gas at the beginning of the next season.
I use the same gas in all my yard equipment, from snow blower to lawn mower following the same routine as above.
You might check with The Filling Station to see if they have a new fuel tank.

Aside from a months-long stretch of inactivity while I was working on motor mounts, gasket replacements, brake maintenance, head/valve grinding, and various other "while I'm at it" chores, my son and I have been driving this car for more than 15 years, never a problem. I've completely drained the tank now and nothing came out but cool, clear gas. As much as I'd like to restrict myself to non-ethanal gas, it's not available locally. I add stabilizer to every tank without exception, we really don't have a no-driving season here in Texas-the closest we come is the never-ending summer when it's almost too stifling to drive. I've always had a glass bowl filter in front of the carb. This whole thing with the fuel seems to have come from nowhere.

JFranklin's suggestion seems the most likely, I got water-laced gas on the last fill and while the car was idle for a few months, it did what sitting water does. I plan on cleaning the tank and marking this down as a one-time event, but with a new sense of vigilance. Thanks everyone.

If it was mine I would just take and drive it and not add anyting to the gas for now.

There is one thing I would add.

About a quart of methanol. 🙂

The alcohol will find any remaining water in the bottom of the tank and run it through the system as a burnable mixture.

Ethanol gas will do the same thing.

What Gene said. 👍