Looking for help building a Gas Vapor system

[RustyLugNut]

Originally Posted by racprops

Found this:

At what temperature does gasoline vaporize?
What kind of heat would have to be applied to a closed circut container to vaporize the gasoline inside?
I'm an amature MAD scientist
Update: OK I'll spill. Gasoline carburetors are about 30% effficient. A gasoline engine CANNOT burn a liquid fuel. The carb turns the fuel into a spray, tiny droplets that do ignite but ver ineffeiciently. That why all the smog pump carp. To reburn what passed through. These are called hydrocarbons. OK back to the spill. If the gasoline can be turned from a liquid gas into a true vapor, which is MUCH more explosive than liquid gas, it will burn at 100%. The result of that is a shocking improvement in fuel mileage. Carbs have been built. IN 1936 Charles Pogue built one that milled out an amazing 200 mpg. Interestingly enough his shot misteriously burned down after he refused to sell it to an oil company. Its no secret though. The plans still exsist. You can find sketches on line. There are three types. heat, cold and electric vaporization. All of which improve mileage from 30 to 100%... a V8 that gets 60-80 mpg? its already been done.


AND:

fuel boils between 104-401F and from what I've read it vaporizes at 450F, and will self ignite at 460-572F. i have also read up on this and am currently thinking of building my own vapor carb, mainly because i am getting around 10 mpg on my old school carb.I'm going to start testing at 50F to see how the gas reacts and take it farther from there. i also thought about using water. the engine will only get you to 250F before it over heats if it hasn't done so by that point, but it might work. so i will see how far i can get with other methods. from what I've read we can't sell what we invent so if i find a way to get it off the ground I'll use it on my own vehicle and share the proven facts with others. just remember that the vapors are really explosive, you don't want to miss calculate and blow up your test facility. also to get 100mpg i saw something that says you would need an air/fuel mix of around 75-1.

AND:

The flash point of diesel fuel is 100 deg. F. for type 1-D fuel. And 125 deg. F. for type 2-D fuel. And 130 deg. F for type 4-D fuel.

I know where you got that post because I had argued with the poster years ago. He had high regard for his own opinions as these people have a tendency to do. I have said it before and I'll say it again, if you look at the particulars of the Pogue "experiment" you will see a lot of ecomodding techniques were used to achieve the so called 200 mpg. And more that were not made public. So what if you can get 200 mpg from a car that was gutted and lightened and was run at only 40 mph? The FreedomCar program from the 90s had gasoline powered vehicles that got 60-80 mpg but with body construction that did not meet safety standards for collision and with engines that did not meet emissions standards. None needed to use vapor carburetors. The more realistic goal of 50+ mpg with fully vetted construction and emissions control is already within manufacturers grasp.

And your continued belief that only 30% of the fuel is burned is erroneous. The poster MAD Sceintist ( he spelled his name that way because of the " i "before "e" thing - really ) would spout that belief even after I produced dozens of research papers that show through high speed photography and heat measurements that 98% of the fuel is burned before BDC ( bottom dead center).

Now, there is something to be said about vapor phase combustion, but as Oil Pan4 has pointed out, it is only in the single digit range of advantage. What you and many others fail to realize, is that heated gasoline vapors are more reactive. As the post on heated airplane carburetors indicated, something is happening that causes detonation if you heat your fuel mix under certain conditions.

In his book about the Mitsubishi Zero Fighter of World War 2, Subaru Sakai mentioned his part in finding an extra several hundred miles of range for his aircraft by leaning of the fuel mix. Though not mentioned in the book, an interview later indicated that carb heat was also used during cruise. When a pilot detected pinging, he would lean the engine. This would continue until the exhaust gas temperature would drop. This indicated the safe area to cruise lean. This allowed the Japanese Empire to strike targets in the Philippines from bases in Formosa ( modern Taiwan ).

The American Aviator, Charles Lindbergh, found out the same phenomenon a short time later and this allowed aircraft fighting in the expanses of the Pacific to gain an extra measure of range.

There is nothing magical about vapor phase combustion. It is well understood and has been used for decades in various applications. Vaporizing gasoline will gain you a few percent in efficiency because of the elimination of irreversible losses ( energy needed to vaporize the droplets ). The hot vapors do gain in reactivity which can allow you to run the engine with reduced ignition lead. This allows you another few percent in efficiency gain. The real gains come from running lean and being able to do so with reduced ignition lead time resulting in more torque production from the same amount of fuel. This results in reduced pumping losses too. Now you will see double digit percentage gains.

All the above is well known and taught at the university level. I can vouch for the theory holding true in various applications.

[Xist]

Is this relevant? From the car collecting thread: 376 MPG | The Story of the 1959 Opel P-1

[racprops]

Originally Posted by Xist

Is this relevant? From the car collecting thread: 376 MPG | The Story of the 1959 Opel P-1

I looked into that and learned:

IT was a flying start, IE they were doing about 30MPH when the did the test run.

That they were allowed to do every trick possible as in Hypermiling..IE Cousting.

The car was stripped and had a two speed chain drive.

The engine was heavy wrapped to run super hot.

The carb was from a very small lawn mower, it was just big enough to bearly power the motor.

I believe the fuel was a special blend.

The only trick left out was a down hill run.

So no it is NOT relevant, as it is no way a by any stretch of a car anyone might ever drive.

I find a 740 MILE mileage run done with three real on the marker cars by the TV show Top Gear on ONE TANK OF GAS much more interesting.

One special VW called The BlueMoton car came with the real rating of 75MPG on diesel, it had a 10Gal tank...So it stock range was/is 750 miles.

The second car was a another special car a Subaru Legacy diesel rated at 50MPG on diesel.

The third car was a Jaguar XJ diesel car...rated at 35MPG.

They each filled their tanks and they were then sealed.

They had a time limit so had to drive at normal speeds.

ALL THREE CARS MADE IT....

Granted they did not drive the English Channel, those MILES was done on a auto train...

So each car only had to be driven 720 MILES on ONE TANK of gas.

The driver of the Jag planed on running out of gas in London...and wasted all he could by running the A/C and seat warmers etc.

He made it as well to even his surprise.

NOW that was a real test and as far as they talked about on camera they did not hypermiling either...

Here is the details:

From https://en.wikipedia.org/wiki/Top_Gear_(series_12)

100 4 Series 12, Episode 4 Economy race from Basel to Blackpool Illuminations (Volkswagen Polo BlueMotion • Jaguar XJ Diesel • Subaru Legacy Diesel) 23 November 2008 7.15

The trio are on a fuel economy race to see who can make it from Basel in Switzerland to Blackpool in northwest England, on a single tank of fuel - May is sensible and selects a Subaru Legacy diesel, Clarkson thinks its pointless and arrives in a Jaguar XJ diesel, and Hammond turns up in a Volkswagen Polo BlueMotion to the scorn of his compatriots, with all three allowed to choose their own routes to the finish line. While Clarkson is interested in just running out near his home, Hammond and May show their competitive sides in this clever race, but once back in Britain, all three soon begin praying they can achieve what they set out to do, with a surprise in store for one of them.

(See my report above...)

All three cars were bought in Basel as stock cars, all three cars are real normal cars. NO mods were done other that some taping of hood seams.

NOW THAT IS A MILEAGE TEST.

Rich

[LittleBlackDuck]

Originally Posted by cRiPpLe_rOoStEr

I got quite surprised when I figured out that some older cropdusters were having the carburettor heat removed and, despite the possibility of using some alcohol-based de-icing fluid and the success of dedicated-ethanol variants of the Embraer Ipanema, no other provision to overcome carburettor icing is fitted to them. BTW have you ever experienced a situation when you effectively had to rely on a carburettor de-icing or anti-icing method?

Yep, a number of times but not all of them when you would expect...

Once when I encountered some supercooled clouds where ice built up and blocked the air intake. Another time was on a warmish, humid day when approaching to land but before the pre-landing checklist was performed. I was running lowish RPM and about 30% power when it started to stumble. Turned on carb heat and all was good.

Normal test of carb heat is to run the engine up to 2000RPM and turn on carb heat. You should get a sustained drop of at least 100RPM for 10 seconds.

Simon

[elhigh]

RE: The Top Gear cars: let me remind you they use English gallons, which are considerably larger than American gallons. So their economy is impressive, yes, but a tad less so.

I have one tank on my own car that went over 740 miles, and a few more that have broken 700.

I have grumbled about that Opel many times. It was designed to do one thing and is utterly worthless for anything else, except inspiring wild-eyed believers. The one thing it really points up, at least to me, is that slowing down and never stopping are two of the best things you can do for your fuel economy.

I think that's an experiment that should be re-performed but with EFI. Get it warm and lean the snot out of it for the record run. Do all the throttling via injector duty cycles instead of relying on an ultra-tiny carburetor, eliminate that pesky pumping loss from the too-small intake. I'd be curious to see how much better, with modern sensors and controls, that same car could do than the old, analog version.

To further your own line of inquiry, Rich, try it with conventional, insulated and heated intakes for maximum fuel vaporization. That could prove informative. The vehicle as a testbed is already there, putting it back to work to further explore what works for fuel economy isn't a bad idea.

This is all blue-skying of course.

[oil pan 4]

If I remember correctly Imp gallons are about 20% more than US gallons.

[elhigh]

Almost but not exactly 20%. That would be too easy.

Interestingly, there are 20 Imperial ounces in an Imperial pint instead of the American 16 ounces. That mostly makes up for the difference between the two volumes, but it must be said, the Imperial ounce is just a teeny bit different.

I meant to ask this question several pages ago: what are the various constituents of gasoline? What are their vaporization temperatures?

Smokey Yunick played pretty hard with heating the intake charge via his so-called "homogenizer" (a turbo charger serving mostly in the function of check valve to keep the heated, expanding fuel-air charge from backwashing back out through the induction system), feeding the fuel-air charge at over 400 degrees into the engine.

It seems to me that his efficiency improvements came mostly through reducing the heat losses of the engine rather than anything to do with the fuel-air charge, though it has to be said that at 400+ the charge was well and truly vaporized.

Ugh. Smokey. Popular Science had a serious crush on that guy for a long time. Still, I'd like to get my hands on those engines or, barring that, roll my own.

All it takes is time and money. So I guess that's going onto the back burner.

[cRiPpLe_rOoStEr]

Considering that a colder air intake flow is often pointed as an improvement to the efficiency of the combustion process, and no wonder the intercooler became a standard feature to the most recent turbocharged engines, I would become concerned about some eventual disadvantage inherent to a vapor fuel system in a port-injected engine.

[racprops]

OK So if your right then the car rated at 75MPG would be something like 60MPG on the US gal?? (75X.20=15-75=60)

So is the English mile the same as the US Mile??

As for heated the current intake, I see a MAJOR lost of power here in the summer even with the engine holding its running temp at 190 with 110 degree intake air.

And when it gets cold a big power boost and better MPG in the cold winter air temps.

SO in my book colder intake is better.

Rich

[ChazInMT]

Originally Posted by racprops

And when it gets cold a big power boost and better MPG in the cold winter air temps.

SO in my book colder intake is better.

Rich

Honest to God, I've been staying out of this conversation, but, seriously...this makes you sound like you pride yourself on being willfully ignorant. It's like saying, "I got up this morning and looked out the window and still didn't see no curve on the Earth, so, the Earth is definitely Flat in my book".

Here's a link to a great conversion tool to try and get your head around British vs US volumetric measurements.