my experience with heated fuel/vapor carb

[rakkassan34]

In my teen years I was facinated and believed in the infamous Pouge carb and the Smokey Yunick Feiro. I then and still do believe fully vaporizing gas will help it burn more completly. At the age of 16 I ran my own experiment with the help of my father whom had already built fuel heaters for his diesel pickup. It was simple copper tubing rapped around a broom handle to coil it. This was then placed around a tube that heated radiator fluid passed through. I put this on my 69 chevy shortbed 305 powered pick up. Other than glasspack mufflers the truck was stock. It also had a 3 speed manual transmission. Once the truck got warmed up it would hesitate and stumble. I thought I was getting vapor lock. I removed the air cleaner and noticed something resembling steam coming out of the carb. Even at idle the intake charge was so hot it pressurized the intake and pushed the fuel vapors out the top of the carb. I cupped my hand behind the carb and the engine fan blew the vapors down the manifold, the engine cleared up and ran great. I cut a cardboard milk carton in the shape of a scoop to direct the engine fan air into the carb, put the air cleaner lid on and it ran great. Only once did it vapor lock and give me a hard time starting. It actually worked! I got up to 30mpg with this setup and it drove great. A family friend offered me $700 for it and I couldn't pass that up. I kick myself in the butt now for letting it go.

Later on in life I worked at a race car shop. The owner was a big time experimenter. I told him of the whole vapor carb stuff and he said yea I've tried it, he claimed a 10% increase in fuel mileage and a 20% increase in power on a Mazda (B2000 I think) pickup. He said it was more cost efficient to use the diesel version ( he got paid to haul off transmission fluid from tranny shops. Would cut the transmission fluid with some diesel fuel and run it in his little mazda's). He showed me what he had left of the vapor experiment. It was an exhaust manifold encased in a sheet metal box. On top was a very small almost lawnmower carb and a hole with a pipe on the other end of the box. The carb squirted fuel directly on the hot exhaust manifold and the engine pulled the fumes in through the pipe at the opposite end. Wow! I thought to myself so simple and no doubt the fuel was getting vaporized there. He said he couldn't figure out how it started when cold but it did.

I still think there might be some gain in fully vaporizing the gas but I feel newer injection systems do a good enough job and the hot cylinders complete this process but one day I'd like to find me a little carburated car and try a low pressure turbo system to act as a one way valve and help push the vaporized gas in.

I searched vapor carbs on this forum with only two results. Has anyone else experimented with this?

[theholycow]

Originally Posted by rakkassan34

The carb squirted fuel directly on the hot exhaust manifold

I searched vapor carbs on this forum with only two results. Has anyone else experimented with this?

There has been some discussion, I'm not sure if anyone experimented. Here's a recent thread:
http://www.gassavers.org/showthread.php?t=7868

[ZugyNA]

Buy some life insurance before testing....


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i do have to say that before i got married, the most entertaining project that i built was a carburetor, and it had no floats, no valves, no jets, nothing to meter the gas flow. it did however have 2 fuel pumps, one in and one out. it worked on the "Chromotography" principle of "wicking" the fuel. worked great. in fact took all day to build. right on the kitchen floor. hooked it up to the heaviest Ford truck i owned that by proportion had the smallest V-8 for an F-350, this truck weighed in at 8900 pounds UNLOADED, and had the roughest ride. for power it had a 351 Windsor MPFI (Multi-Port Fuel Injected) and i found that by just tripping the inertia switch (a safety cutoff for accidents to shut off all power to the fuel pumps) that i hooked up the "carburetor" and measured outside temperature, which was -10 F and proceeded to pour in 1 cup of gasoline, close the lid on the carburetor, which was mounted as far from the engine as physically possible, and closed the hood, jumped in, fired it up, and drove like a madman in december, in winter, on ice, in a 25 MPH zone in circles around our subdivision, the "lap" around the subdivision's outer "loop" was aproximately 2.5 miles long. i did 4 laps, and finally pulled it into the driveway, shut the truck off, and removed the carburetor. top achieved speed on the "straight-a-way" (on ice remember dont need to wreck my truck for the hell of it) was 55 mph. i then poured out the entire contents of the carburetor, and then took the "wicking material" and squeezed all the gas out if it, and measured that, all in total my truck had consumed in a 10 mile run about 1/2 of a cup of gasoline at ambient thermal temperatures of -10 F (again that is ten degrees below ZERO F) anyone want to build one of these carburetors is more than welcome to. my wife (date at the time) thought it would never work, it was too simple, and she saw no was something like that would work. she also went to school and took auto-diesel technology courses, and she changes the oil and does the tune up on her own vehicles by herself. she's from a farm, and she's the type that could chew up bolts and spit out the heads. but, then again that could be a bad thing too.


1/2 cup = .031 gallon 1/ .031 X 10 miles = 322.5 mpg?

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ok carburetor instructions for assembly:

get an old military ammo can. you are going to need a welder to put some ducting on it (piping if you will) and then you are going to need what my construction friends call "Elephant diapers" about 12 of those. it is very important that the ducting be put on opposite ends of the ammo can. having a lid that opens is very important. also invest in 3 CO2 type fire extinguishers, others types will be self explanatory after you try to use it ONE time. my system was not a straight through for the reason that i WANTED turbulence inside the ammo can. i used 2" pipe coming in AND going out. this is important. in the F350 that i ran it on, it has these really long air ducting tubes that go from the throttle assembly to the air cleaner on the fender. i left the throttles intact. i just re-routed ONE tube to the ammo can, and PLUGGED the other. now the guts of the ammo can must be carefully measured for assembly. this is what the elephant diapers are for. where the pipe goes in and comes out of must be at the same height. my pipes were directly opposite, but on caddy corners to the end so the air flow had to make a "S" pattern as it flowed through.

the elephant diapers are cut into rectangular strips and placed in VERTICALLY: as in standing on end like the letter "I" the can lid opens from the top. the length of the Elephant diapers is directly proportional to the height of the CENTER of the inlet and outlets. the tops of the material should end in the center of the air stream of the inlets and be level across the top. (as best you can).

HOW IT WORKS: when the LIQUID gas is in the container, it is READILY absorbed into the Wicking material (Elephant Diapers), as the wicking material soaks up the gas, the gas will "wick" it's way to the top of the material. then as the air flows across the top of the material, it "dries" the gas off, thereby allowing more room for the wick to absorb more gas. here's the hitch: there is no rich or lean spot. there is no need for an accelerator pump, and if you need more fuel for acceleration, just open the throttle, the vacuum inside the manifold will pul more air across the "wick" and thereby get more fuel.

...there is not another "FREEFLOW" carburetor in existance out there on earth yet. this FREEFLOW action happens because as more air is drawn across the top, more fuel is "dried" or "PROPERLY VAPORIZED" and thoroughly mixed with the airstream. simple. now be careful, watch your fuel level!!!!

THIS CARBURETOR IS DANGEROUS!!!! rule of thumb, old carbureted engines: BACKFIRE out of the EXHAUST means TOO MUCH FUEL, however the opposite of both is true too, because BACKFIRE out intake means NOT ENOUGH FUEL!!!! backfire out the intake is extremely dangerous because it will flash back to your freeflow carburetor, and hence the need for the CO2 Fire extinguishers, the other type make a mess and WILL ruin your carburetor. it's that simple. no floats, no jets, no adjustments, no needles, no valves, no venturii, and no bull****.


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what i call Elephant Diapers are AKA ABSORBENT OIL CLEAN-UP MATS. they are found at industrial stores, NOT HOME DEPOT, NOT LOWE'S NOT WALLY WORLD NOT SAMS CLUB AND NOT SCHUCK'S NOT NAPA, NOT CARQUEST, PEPBOYS, AUTO-ZONE...they are industrial use, and you have to go to an industrial supply/hardware store. the larger the bag (QUANTITY), the cheaper they are.

[rakkassan34]

now that's pure vapor! Please do more of these wicking carbs. I'd like to see(hear of) more of these along with the results. Did the truck run lean? I'm not sure how you would adjust the air fuel ratio or even if it's needed.

[Jay2TheRescue]

I would say you need a flame arrestor to prevent backfires through the intake causing a fire. I know Rusty (my 86 Chevy C-10 pickup) has a flame arrestor built into the air cleaner assembly. Air cleaner assemblies for 80's model chevy trucks are probably cheap at your local junkyard. I can see how this works for a "test" setup, but how do you regulate the amount of fuel in the can? I figure an electric fuel pump can move it from the tank ok, but then you may flood the box with fuel. Also to consider is what happens when you shut the vehicle off? All this fuel is there evaporating whether you are driving or not. I think unless the vehicle is going to be run 24/7 this isn't going to be practical.

[rakkassan34]

this wicking carb somewhat reminds me of my airbrush. I wonder if I put gas in my airbrush, set it on a fine setting, point it at my lawnmower hmmm. Probably just blow my hand off somehow. Yea I can see me running around my yard on fire with the kids laughing at me. Someone else try this.

[Jay2TheRescue]

Originally Posted by rakkassan34

this wicking carb somewhat reminds me of my airbrush. I wonder if I put gas in my airbrush, set it on a fine setting, point it at my lawnmower hmmm. Probably just blow my hand off somehow. Yea I can see me running around my yard on fire with the kids laughing at me. Someone else try this.

Don't forget to set up the camcorder and then send the result to AFV...

[scoob87]

if you see vapor, that was alot of liquid gas. A 30+ mpg car is invisible to look down the barrel of a carb..you can hear it when throttling, and maybe an acclerator pump squirt in sight, but nominal run to achve true gas mileage should be invisible. I have an 87 scoob that goes way way beyond on its hot intake and coolant at the base of carb (car hits 215 if to treat it like the factory did, fuel mileage like the most conservative beetle if to be insanely conservative into the 50s mpg). Experiments in lean conditions are dangerous. I leave that stuff alone, but if someone is smarter than hitachi, weber , holley, carter, stromberg, and many others combined, havadit.

[theholycow]

Originally Posted by scoob87

if someone is smarter than hitachi, weber , holley, carter, stromberg, and many others combined, havadit.

A lot of of what we do here is second-guessing the big-money companies, beating their huge R&D departments/budgets with grassroots effort, guessing, and so on. It sounds impossible, but the reality is that we have far different priorities than they have. We can ignore things that are important to them and concentrate on fewer priorities, with a stronger sense of direction and fewer compromises for it.

[soletek]

Well said, theholycow!

I have been a machinist for quite awhile now and one thing you learn as a machinist is that there are often many, many different ways to get the same thing done and come out with as good or better results.

I know of one guy in my area who is using a submerged diesel glow plug to boil the gasoline in a ported chamber to feed fumes to the engine at idle during low engine demand situations. He seems to be very pleased with the results.

The wicking method is intriguing. I wonder if breaking up the vapor via sound waves would promote even better results. For example, using a reptile tank mister downstream of the wicking element.