# Vapor fuel tank carburetion



## cfellows (Mar 21, 2013)

While certainly not as authentic as carburetors in model engine making, I have had pretty good success using vapor fuel tank carburetion on my model IC engines.  Vapor Fuel Tanks have been used for smaller engines in the past and I heard that Ford Motor Co had actually done quite a bit of research on the use of vapor fuel carburetion in the early days.  Jan Ridders has popularized the vapor fuel tank on most of his model IC engines, making attractive tanks that work well for him. 

The vapor fuel tanks are very easy to make and pretty much work with little or no adjustment.  Following Jan's examples, I have added an adjustable mixer that allows the introduction of more or less air with varying degrees of success.  My experience has been that my vapor fuel tanks produce a mixture that is barely rich enough in the best of circumstances and hardly require any need to make the mixture leaner.  In addition, the vapor carburetion method is extremely sensitive to fuel level in the tank, partly I expect because of the surface area presented.

So, I'm trying a different setup that hopefully will resolve some of the above problems.  I have reasoned that a flat, rectangular tank would give me larger fuel surface area resulting in more fuel evaportation and would make the fuel level less of an issue because the surface area would remain unchanged with differing fuel levels.

I found a nicely shaped bottle in my better half's perfume collection, but, unfortunately, no amount of pleading or wooing would cause her to relinquish it, even though it was nearly empty.  So, looking on Ebay, I found a number of such empty bottles of the same brand.  For those who are interested, it is called Red Door made by Elizabeth Arden.  Here are some pictures:







Without the Lid...






The other red part pulls off with very little coaxing...






And here's what it looks life after cutting off the top with my Harbor Freight Wet Tile Saw...






The wet tile saw works very well.  The trick is to go slow and keep the bottle straight as you go.  I just pressed the bottom against the included saw fence as I pushed it past the blade.

As an added note, if you decide to go this route, you better be prepared to explain to the spouse why your hands, clothes and shop smell so good!

Next I'll machine a new end for the bottle and add some plumbing.  Stand by...

Chuck


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## AussieJimG (Mar 21, 2013)

I will be following your experiments with great interest Chuck. I have also encountered the problems you mention and have tried bubbling the air through the fuel, changing the shape of the tank (including your Pimento jar solution) and changing the size of the intake hole to increase the velocity of the air but all to no avail.

I found very few references on the web although, as you say, these vaporisers were used in the early days. One design I found used wicks to increase the surface area but I have not explored this.

I am amused by your reference to explanations of smelling nice. It reminded me of the story of two blokes in the change room at the golf club. One was putting on a pair of pantyhose. The other asked how long have you been wearing those? His partner replied: "Ever since my wife found them in the glove compartment of the car".

Jim


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## cfellows (Mar 21, 2013)

AussieJimG said:


> I will be following your experiments with great interest Chuck. I have also encountered the problems you mention and have tried bubbling the air through the fuel, changing the shape of the tank (including your Pimento jar solution) and changing the size of the intake hole to increase the velocity of the air but all to no avail.
> 
> I found very few references on the web although, as you say, these vaporisers were used in the early days. One design I found used wicks to increase the surface area but I have not explored this.
> 
> ...


 
Thanks, Jim.  I had heard a variation of that story where the guy was wearing lace panties.  

I've also tried warming the fuel by sitting the tank on an electric coffee cup warmer.  Seemed to help some but that wasn't an accessory I wanted to add to the engine...

Chuck


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## cfellows (Mar 21, 2013)

Did some more work this afternoon.  I used my dremel with a diamond cutoff blade to cut a slit along the bottom of the bottle.  When the bottle is laid flat, the slit will be on top and provide the air inlet.






The slit didn't turn out nearly as straight and crisp as I had imagined beforehand, but it will be quite functional.  I decided a slit would be better for even distribution across the fuel surface.






I made up an aluminum block for the new bottle top and milled a slot in it to fit the bottle top.  The scrap piece I used had a chamfer on one corner.  I'll have to figure out how to incorporate that into the final design. 





An o-ring inserted into the slot will prevent leakage.  The bottle will have to be clamped to the cap.

Chuck


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## aarggh (Mar 22, 2013)

What a brilliant idea Chuck! Very interesting approach. If you had some of the older medicinal or alcohol bottles with raised logos that would be quite novel to do.

cheers, Ian


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## Herbiev (Mar 22, 2013)

Brilliant Chuck. Great idea


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## deverett (Mar 22, 2013)

I'm very interested in this idea, Chuck, because I have castings for an Atmospheric Gas Engine.  The model is a copy of the Schoenner and Paradox engines of the early 20th century which ran on 'town gas'.

Town gas, which I think was methane, is no longer available and the nearest gas is acetylene.  Over here (Ireland) cylinders can only be rented and a cylinder would last me at least 5 lifetimes for running this small engine!

Bruce Davey, the designer of the engine, suggests 'carburetted propane'.  Basically this is propane bubbled through petrol.  Neat propane will not work on this engine because the ignition range is not comparable to town gas.  Running the propane through petrol will, apparently, broaden the ignition range to make it closer to town gas.

Because there is only a possibility of the engine running on this gas mixture, I am reluctant to start building it.

http://www.stationary-engine.net/forum/showthread.php?t=20540&highlight=atmospheric+engine  shows an A.G.E. and an original Paradox engine.
http://www.smokstak.com/forum/showthread.php?t=48698 for more pictures and an original Schoenner engine.

Dave
The Emerald Isle


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## cfellows (Mar 22, 2013)

deverett said:


> I'm very interested in this idea, Chuck, because I have castings for an Atmospheric Gas Engine.  The model is a copy of the Schoenner and Paradox engines of the early 20th century which ran on 'town gas'.
> 
> Town gas, which I think was methane, is no longer available and the nearest gas is acetylene.  Over here (Ireland) cylinders can only be rented and a cylinder would last me at least 5 lifetimes for running this small engine!
> 
> ...


 
Hmmm, never thought of bubbling propane through liquid fuel.  I wonder if town gas is the same as illuminating gas?  

Chuck


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## Woodster (Mar 22, 2013)

deverett said:


> Town gas, which I think was methane, is no longer available and the nearest gas is acetylene.
> Dave
> The Emerald Isle



You can make your own Town gas by heating coal in a kettle, then scrubbing the gas in water. Apparently quite a simple process.


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## cfellows (Mar 22, 2013)

Woodster said:


> You can make your own Town gas by heating coal in a kettle, then scrubbing the gas in water. Apparently quite a simple process.


 
So, the next question would be, "Where can you get coal"? 

Here's the results of my perfume bottle fuel tank...

http://www.youtube.com/watch?v=EsJie5oVgGg&feature=youtu.be

The greater surface area of the tank makes the engine run richer.  In fact, if I close the air mixer completely, the engine will stop running.  

There seems to be a lot of different dynamics in determining how the vapor fuel tanks operate.  I'm going to continue to experiment with some different designs, but for now, I've got the engine apart so I can paint it and make a base for it.

Chuck


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## AussieJimG (Mar 22, 2013)

Town gas, coal gas, illuminating gas: http://en.wikipedia.org/wiki/Coal_gas

I wonder why an engine that ran on town gas would not run on propane. In fact, I was at a historic engine rally last weekend where there was an engine, originally designed to run on town gas, happily running on propane. The owner had made a bladder using non-percolating canvas fire hose to further reduce the gas pressure. Made from 38mm hose about 1m long, this bladder just gently expanded and contracted as the engine breathed in the gas.

It might be worth seeking advice from one of the local historic engine societies.

Jim


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## cfellows (Mar 23, 2013)

While the paint and varnish are drying I'm moving on with my next fuel tank design.  This one will be aesthetically more pleasing.






The glass part is about 1 1/2" OD and 4" long.  I used my tile wet saw to cut the top off.  The original bottle was about 7" tall and has pretty thick walls.  I cut a groove inside the aluminum top and inserted a 1 5/8" x 1 1/2" o-ring.  The bottle is a snug fit inside the o-ring and doesn't leak any fuel.






I will need a tail piece to keep the bottle from working it's way out, but will not need any clamping pressure to seal the container.  Still have some work to do before this one is finished.

I have a third tank I also want to try.  It will be made from a 1 1/2" square bottle that will be about 4" long.  With the square cross section, the surface area of fuel will not decrease as the fuel level falls.
Chuck


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## canadianhorsepower (Mar 24, 2013)

> I made up an aluminum block for the new bottle top and milled a slot in it to fit the bottle top. The scrap piece I used had a chamfer on one corner. I'll have to figure out how to incorporate that into the final design.


 

Hi what about chanfering the other side to make it simetrical?


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## cfellows (Mar 24, 2013)

canadianhorsepower said:


> Hi what about chanfering the other side to make it simetrical?


 
That's probably what I'll do if I wind up using this tank.  The only thing I don't like about this one is the fact that I have to clamp the bottle against the o-ring.  I have my eye on one of the miss's spice bottles that is square with a round top.  Might have to wrestle it away from her...

Chuck


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## WCPenney (Mar 25, 2013)

Chuck, what part of the U.S. are you from? There is a small coal company in Lebanon Maine (The Lebanon Coal Co.) about a mile from my house. You might give them a ring and see if they would ship you a bag. (207) 339-9689. I've been thinking of picking up a few 40# bags for a little laundry stove that I bought last year. I could always toss a ziploc full into a flat rate box...


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## cfellows (Mar 25, 2013)

WCPenney said:


> Chuck, what part of the U.S. are you from? There is a small coal company in Lebanon Maine (The Lebanon Coal Co.) about a mile from my house. You might give them a ring and see if they would ship you a bag. (207) 339-9689. I've been thinking of picking up a few 40# bags for a little laundry stove that I bought last year. I could always toss a ziploc full into a flat rate box...


 
Thanks for the kind offer but my question was more tongue-in-cheek than a real query.  I really don't have any desire to experiment with town gas at this point.

Chuck


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## tornitore45 (Mar 25, 2013)

cfellows said:


> So, the next question would be, "Where can you get coal"?
> Chuck


 
Simple, you behave badly for a full year and Santa will bring you a sack of coal by Christmas.

Seriously, try to place a wick material inside the tank.  The problem is to find a material that resist the fuel.  Basically we want to make a humidifier.  Direct the exaust (part of it) toward the tank, may be hidden in the engine base.


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## cfellows (Mar 25, 2013)

May try a wick of some kind later on.  For now, I've found a near perfect shape for my next experiment.






I found it in the local super market in the spices section.  It came full of Rosemary for $1.99.  It's 4" long x 1 3/4" square, I would have preferred 1 1/2" square, but think this will do.

Chuck


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## cfellows (Mar 25, 2013)

Here's an interesting video just posted by nrowland.  He is using a wicked fuel tank, but it's not clear to me where the wick is...

[ame]http://www.youtube.com/watch?v=AE9PdtM-DFM[/ame]

Chuck


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## jixxerbill (Mar 25, 2013)

Chuck just an observation here, but is there a way to put some kind of cloth material between where the air comes in and where the air goes out ? So the air has to pass thru the cloth. Suspend it touching the fuel also so the cloth stays saturated with fuel.. Just wondering if it would get more fuel vapor into the air stream... Bill


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## aonemarine (Mar 25, 2013)

I remember hearing years ago that they switched fuel blends in the summer to a fuel that doesn't evaporation as easily.   
Maybe heat the fuel up some by running an exhaust loop thru it....


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## cfellows (Mar 26, 2013)

tornitore45 said:


> Simple, you behave badly for a full year and Santa will bring you a sack of coal by Christmas.
> 
> Seriously, try to place a wick material inside the tank.  The problem is to find a material that resist the fuel.  Basically we want to make a humidifier.  Direct the exaust (part of it) toward the tank, may be hidden in the engine base.



Hey Mauro, didn't recognize you right away.  I'm seriously going to have to investigate the whole wick idea.  After seeing nrowland's video, I have to agree with you that it would probably help.

Chuck


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