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Discussion Starter · #1 ·
I was digging around in some old stuff and found some papers from 1990. From a book called the 200MPG carburetor by Allen Wallace(this is in no way to infringe on his copyright, but to mearly inform others on this forum).
Lets all pretend that this is all in quotes.

The carburetion system begins at the point of air entry into the system and ends at the point of ignition, therefore- theintake manifold and the heads are part of the carburetion system as are the combustion chambers. The heatwithin these parts of the system is what tends to vaporize fuel so that it can burn. The carburetor only turns the fuel into a fine misty spray and meters it to coinside with the air flow. In the average car of today, only about 20% of the fuel ever gets vaporized for the burning process, the balence is what ends up as carbon build-up inside the engine and what is called unburned hydrocarbons being collected by the catalytic converter or coming out the tailpipe.

You can disprove the 15:1 air/fuel ratio with your own car and a little of you time. Fill your tank and then take your car out on the highway, drive at 55 mph for one hour-turn around and return to the same station you filled up at and refill your tank. Note the mileage on your odometer at the beginning and the end of the drive. Now go home and get out your calculator. You're going to figure the air/fuel ratio for the engine under ideal conditions at a steady speed. You drove 110 miles, now figure your mpg by dividing the number of gallons to refill your tank into the 110 miles. Now say for example, you got 18 mpg, you used 6.1 gallons of gas-at six pounds per gallon that is 36.6 lbs. Now you will have to figure the amount of air you used, and at 13.1 lbs per cubic foot. If your engine is a 300 cubic inch v-8 and turns 2250 rpm at 55 mph it will draw in 11,718.75 cubic feet per hour-two hours would be 23,437.5 cubic feet or 1,789.1 lbs. Now divide the air by the fuel (1,789.1 lbs air and 36.6 lbs fuel) and you get a fuel/air ratio of almost 49:1.....

The formula for fuel ratio to air is always figured in weight, so the correct formula is as follows: Gasoline at 6 lbs per gallon / air at 13.1 lbs per cubic foot.---Cubic inch displacement of engine divided by two (piston only draws air on every other stroke) multiplied by engine rpm, divided by 1728 (1728 cubic inches per cubic foot) multiplied by 60 (the # of minutes per hour) equals cubic feet of air / gasoline gallons multiplied by 6 lbs equals weight of gasoline / cubic feet of air multiplied by 13.1 equals weight of air -- divide weight of air by weight of gasoline consumed for same period of time equals air/fuel ratio.

It's plain to see that if you get a 49:1 air fuel ratio at a steady speed on the highway and if your carburetion system is only 20% efficient, a 60 to 80% efficiency would increase mileage drastically. If you are getting 18 mpg now and could increase efficiency to 80% your mileage
would be better than 70 MPG.

[This book goes on about several different prototype carbs that get hundreds of miles to the gallon. I wont bore some of you readers with all of the info but if you want it I'll find a way to post the text (and pictures) on the web somehow.]
I was extremely interested 4 yrs ago when I found this book and happy when I found it today.
If you want all the specs. (lots and lots here) I'll find a way to post it. Tons of details for us gearheads.
JN
 

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Discussion Starter · #2 ·
Re: Anyone interested in mpg read this. (llllllong

As the piston moves down to draw air, there is a vacuum in there right? So don't you have to take into account the how much vacuum there is to calculate how much air is used?
 

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Discussion Starter · #3 ·
If you buy that I'll sell you a "water engine

> As the piston moves down to draw air, there
> is a vacuum in there right? So don't you
> have to take into account the how much
> vacuum there is to calculate how much air is
> used?

Please. The amount of fuel vaporized and burned is MUCH higher than 20%. The new cars today release almost no unburned hydrocarbons and if the catalytic converter had to destroy 80% of the gas going through the engine it would melt itself. Go find a better book.

Sorry, just had to say what was on my mind.

Alex
 

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Discussion Starter · #4 ·
Re: If you buy that I'll sell you a "water en

> Please. The amount of fuel vaporized and
> burned is MUCH higher than 20%. The new cars
> today release almost no unburned
> hydrocarbons and if the catalytic converter
> had to destroy 80% of the gas going through
> the engine it would melt itself. Go find a
> better book.

> Sorry, just had to say what was on my mind.

> Alex

The book is simply trying to inform some people on other possibilities. It isn't selling anything. After all it was copyrighted in 1980, not too long after the fuel crunch of the 70's. I just wanted get other's opinion on it. BTW I know a small engine repair shop whose old and wise owner has a riding lawn mower with very similar effects using water injection to control detonation of the very leaned out mixture.
JN
 

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Volumetric Effeciency and 4 strokes.

There are a few fundamental errors in his assertions. First, he is assuming that the engine has a 100% Volumetric Effeciency. That says that it sucks in the full volume of the cylinder every revolution. That is only really acheived in race engines at high rpms. Figure 50-60%. Also, he is assuming that it is taking in air each time, not every 4th stroke, or half of the rpm. So factor those two things in and you have a much more realistic figure.
-bob hanvey
 

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Re: If you buy that I'll sell you a "water en

> Please. The amount of fuel vaporized and
> burned is MUCH higher than 20%. The new cars
> today release almost no unburned
> hydrocarbons and if the catalytic converter
> had to destroy 80% of the gas going through
> the engine it would melt itself. Go find a
> better book.

> Sorry, just had to say what was on my mind.

> Alex
I'm with you, Alex... BTW, am I the only one that noticed that they were claiming that AIR weighs 13.1 lbs/cubic foot (!) ? AND using that number for their calculations? Holy crap - that's some pretty dense air...
 

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Discussion Starter · #7 ·
Re: Volumetric Effeciency and 4 strokes.

> There are a few fundamental errors in his
> assertions. First, he is assuming that the
> engine has a 100% Volumetric Effeciency.
> That says that it sucks in the full volume
> of the cylinder every revolution. That is
> only really acheived in race engines at high
> rpms. Figure 50-60%. Also, he is assuming
> that it is taking in air each time, not
> every 4th stroke, or half of the rpm. So
> factor those two things in and you have a
> much more realistic figure.
> -bob hanvey

Actually, if you read it carefully, he says to divide by two the amount of air because of it being a 4 stroke. Also agree that it doesn't suck in the full volume of the cylinder. Unless you have a turbo.:) Then you get more then 100% The book is wrong,
 

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Discussion Starter · #8 ·
Not 100% wrong

> Actually, if you read it carefully, he says
> to divide by two the amount of air because
> of it being a 4 stroke. Also agree that it
> doesn't suck in the full volume of the
> cylinder. Unless you have a turbo.:) Then
> you get more then 100% The book is wrong,

Peripheral ported rotary engines can actually get MORE than 100% volumetric efficiency, don't ask me how, my best guess is that the nature of the port and the motion of the rotor get 100% in extremely well, and then the last few percent get rammed in by the inertia of the moving air behind it.

Project#2501
 

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Discussion Starter · #9 ·
Re: If you buy that I'll sell you a "water en

> I'm with you, Alex... BTW, am I the only one
> that noticed that they were claiming that
> AIR weighs 13.1 lbs/cubic foot (!) ? AND
> using that number for their calculations?
> Holy crap - that's some pretty dense air...

No, no, didn't you see the footnote on that page. They were strictly discussing the density of air on Jupiter, not earth. But hey, what's the big deal about messing up a few details when we're talking about a perpetual motion machine. Opps, I mean a radically efficient new carborator.
 
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