Simplified Vapor Fuel Tank

[cfellows]

I came up with a simpler Air mixer for a Fuel Vapor Fuel Tank. Here is a Picture.

The vapor fuel tank draws air into the tank through an air inlet. The air passes over the surface of the liquid fuel and draws fuel vapor through the outlet and to the engine. However, the pure vapor is too rich and needs to have additional air mixed in.

In my version, the inlet tube going to the engine has a 1/8" wide slot cut into the side. A threaded collar fits over the tube, and by screwing and unscrewing the collar, the slot is more or less uncovered, allowing more or less air to be mixed with the fuel. This adjustment isn't particularly sensitive since the collar and tube OD are threaded at 1/4 - 28.

I just installed this setup on my hit n miss engine and it works great. I used a small pimento jar for the tank and fitted the brass tubes to the jar lid. The engine starts first pull every time and continues to run as long as there is fuel. Pictures to follow later.

Chuck

 

[Maryak]

Chuck,

Very Nifty. :bow: :bow: I am thinking, (no don't worry :), about fuel for my hit and miss. Truth is I don't have a clue what it should be.

Gas - as in LPG. ???

Petrol - as in US gas - Octane level. ???

Coleman fuel - don't know what that is - Cetane Index ??? - imagine it's some kind of kerosene based lamp or stove fuel. ???

Any help would be greatly appreciated.

Best Regards
Bob

 

[cfellows]

Bob,

Coleman camp fuel is made from Naptha Petroleum. Very clean burning. I originally fired my engine with 87 octane gasoline. I had a standard fuel tank with a simple needle valve type carburetor, no butterfly. I was able to switch to Coleman fuel with no changes to the fuel tank or carburetor.

Recently I changed to the vapor fuel tank and no carburetor, just the simple air mixer in this post. It starts very easily and runs great.

Will upload a video later.

Chuck

 

[cfellows]

Here's a video of my Hit n Miss with the new, Vapor Fuel Tank attached. It's a pimento jar! The setup is as described and drawn further down this thread. It's also described in the video.

[ame=http://www.youtube.com/watch?v=wbqIfcjaIY8]http://www.youtube.com/watch?v=wbqIfcjaIY8[/ame]

Chuck

 

[shred]

Cool. This is with no carb at all?

You should put some red food coloring and pimentos in the jar... an a label that says "Caution, Extra Strong"

 

[putputman]

Chuck, you did it again. Such a simple solution to a nagging problem on most I.C. engines. Can't wait to try it out.
Thank you and count your karma.

 

[CMS]

Very clever, think I'll try this too.

 

[Powder keg]

Pretty cool Chuck!!! Does the efficiency go up? I imagine it would?

 

[cfellows]

Pretty cool Chuck!!! Does the efficiency go up? I imagine it would?

I don't really have any way of knowing. I do know, however, that there is no flooding. Also, I expect the droplets of fuel are much smaller than those produced by a tradional carb.

I also don't know about throttling. I assume you could put a butterfly between the engine and the air opening, but then I also expect you would have to tweak the air mixer if you moved the throttle.

Chuck

 

[Jan Ridders]

I came up with a simpler Air mixer for a Fuel Vapor Fuel Tank. Here is a Picture.

The vapor fuel tank draws air into the tank through an air inlet. The air passes over the surface of the liquid fuel and draws fuel vapor through the outlet and to the engine. However, the pure vapor is too rich and needs to have additional air mixed in.

In my version, the inlet tube going to the engine has a 1/8" wide slot cut into the side. A threaded collar fits over the tube, and by screwing and unscrewing the collar, the slot is more or less uncovered, allowing more or less air to be mixed with the fuel. This adjustment isn't particularly sensitive since the collar and tube OD are threaded at 1/4 - 28.

I just installed this setup on my hit n miss engine and it works great. I used a small pimento jar for the tank and fitted the brass tubes to the jar lid. The engine starts first pull every time and continues to run as long as there is fuel. Pictures to follow later.

Chuck

 

[Bill Mc]

Hi Chuck - Approximately what is the diameter of that jar because the exposed surface area would be very important as to how rich the vapor is as well. Part of that calculation would be as to what displacement the engine is also as to what the engines needs for proper combustion. - Billmc

 

[zeeprogrammer]

Just came across the pimento jar video. That's a great post. Thanks.

 

[doc1955]

Nice!
Pimento jar what a great idea I was thinking of adding a vapor fuel system to my IC motors and I like the jar idea.
And Shred "extra strong" Rof} Rof} I like!

PS Nice running engine!

 

[bearcar1]

Somehow I missed this video for some reason but Chuck, that is a fantastic method and execution of air/fuel control. Well done! BRAVO! (it would be humorous to put some faux pimentos made from resin inside the glass jar) ;D Great running engine as well, what is it modeled after?

BC1
Jim

 

[cfellows]

Hi Chuck - Approximately what is the diameter of that jar because the exposed surface area would be very important as to how rich the vapor is as well. Part of that calculation would be as to what displacement the engine is also as to what the engines needs for proper combustion. - Billmc

Bill, the pimento jar is about 2" diameter on the inside. The engine has a 1.0625" bore and 1.5" stroke.

Thx...
Chuck

 

[cfellows]

The vapor fuel tank has been around for a long, long time. There are a number of old model engines on youtube which show a setup using a small jar similar to mine.

Jan Ridders resurrected the vapor fuel tank and, as far as I know, was the first to add an air mixer in the line. He has built several versions and the latest used a slotted disk that attached pretty close to the tank.

The only change I made was a simpler air mixer comprised of the threaded collar over a slotted opening in the fuel line. As some of you may have seen, I had also built a version of Jan Ridder's fuel tank from his plans for my Henry Ford engine. It was only after I tried out his tank design on my hit n miss engine that I decided to adapt the jar design and to try to simplify the air mixer.

So, thanks to Jan for his groundwork and for sparking the idea in the first place.

Chuck

 

[eskimobob]

Interesting - when I have seen these before, I had assumed that the tube which lets air in actually reached into the fuel in order to cause the air to bubble through the fuel - it seems that this is not necessary 8)

 

[cfellows]

Interesting - when I have seen these before, I had assumed that the tube which lets air in actually reached into the fuel in order to cause the air to bubble through the fuel - it seems that this is not necessary 8)

You're right, most of the earlier designs do show the inlet tube extending down into the fuel. But, as Ridders discovered, it doesn't have to. The rush of air into the container on the intake stroke generates quite a bit of turbulence in the liquid fuel. Also, if the engine fires back or the intake valve leaks, you don't get a geyser of fuel coming back out the air inlet pipe.

Chuck

 

[eskimobob]

Also, if the engine fires back or the intake valve leaks, you don't get a geyser of fuel coming back out the air inlet pipe.

I hadn't considered that but I would imagine that is very nasty - your method seems much safer

 

[NickG]

Good work Chuck, thanks for this. It will no doubt be very useful to me and a lot of other people.

Nick