OK, I had to register just to reply to this thread.
Of the replies here, Ted Hart was the only one who spoke some truth into this matter and he was ignored.
I design, fabricate, and tune my own vehicles for both daily driving and racing purposes. This vehicle in particular is NOT built for mpg. My other vehicle (a minivan) is why I was poking around here.
My "toy" is a turbocharged 4 cylinder.
Ted Hart was accurate but not descriptive for this audience.
Here's how today's MAF-controlled vehicles are tuned:
They run off various pre-determined fuel, timing, and MAF-transfer tables which are set by the original manufacturer.
ANY modifications to the fuel, spark, or air will throw off these preset measurements and requires a re-tune.
There are various sensors such as the MAF, O2 sensor, and knock sensor which will attempt to compensate for these changes but it will not be optimal.
By drastically increasing the air intake temperature you all have completely thrown off some if not all of these OEM tables.
The danger here is in the spark timing.
The ECM can only adjust for so much hot/thin air before it will start to detonate (the combustion starts before the piston is in place).
Too much/constant detonation and your nice "efficient" burn is now an inferno burning holes in your valves and pistons.
What I must be concerned with in my turbocharged vehicle is keeping the intake temperatures down to reduce spark knock.
Due to extreme pressure in the cylinder introduced by boost, even the slightest knock can burn holes in the rotating assembly parts.
This is the extreme and highly shortened version of what you are doing to your engines over a long period of time.
It is highly possible that the knock sensor in your vehicle is compensating by pulling timing for this hot/thin air.
If that sensor goes bad, good-bye engine.
I say this to inform you, not to deter you from your goal.
There is a reason auto manufacturers use built-in cold-air intakes nowadays.
It is the ideal for the balance of engine longevity, power, and mpg.
Its nice to be able to control your timing /fuel tables through an engine management system when running a WAI. This way you can tune to run extremely high IAT's and not hurt anything at very light load conditions.
I came across this car on line that has 376 mpg! crazy stuff. It seems that it uses a hot air intake from the cooling system/radiator. The hot air vaporizes the fuel being injected. Also they us a smaller carburetor than the original one that came with the car. It's the 1959 Opel P1 experimental car from 1973 Shell test vehicle. I wonder what kind of horse power it has. I suppose if you run a car at 30 mph you will get real good gas mileage.
The text that is there with the carburetor: "For a carburetor junky like me this has been a most enjoyable thread. It is estimated there were over 200 different carburetors made for the T engine.
The Wizard (1st photo), and Simmons Super-power sold by Western Auto are among the more common ones. They were essentially twins. They both had a heating coil and both used a pot metal flapper to regulated low speed mixture."
The coil in the carb pic above looks more like a turbulence device to me. I don't see how it could be an electric heating coil since both ends appear to be connected together- maybe there is a very thin insulating washer in there?
It looks like the bolt goes through an insulating washer, one end of the coil contacts the bolt, and the other end contacts the carburetor body. I'm not sure that little coil can provide much heat though...maybe if it got insanely hot, but then I'd be worried about concentrated heat so close to fuel.