100 mpg carburator

[masterrig 1]

This, might be a good reason for such a carburator...

[billvon 3,006]

>Now let's take the same 2x4 and try to ignite it whole using the kitchen match.

It would be sure to fail. The equivalent would be ignition failure, characterized by backfiring, engine imbalance and severe loss of power. Rapid failure of the catalyst and oxygen sensor would result, rendering the car undrivable after a short time.* If this happens, then MSD might make a difference, if it could somehow ignite the mixture on the second or third spark when the first one failed.

However, if your car is operating normally, MSD doesn't do a damn thing. To use the above analogy, it's like claiming that a gasoline-soaked bonfire will look really impressive if lit with a flame thrower, but will really, really suck if it's lit by a puny propane blowtorch.

MSD is akin to the fuel line magnets, catalysts and gas additives that proponents claim will significantly increase your gas mileage. Some are quite successful at separating people from their money, but none do much in the way of increasing gas mileage in a working car.

* = (This once happened to me when a rat chewed through two of the eight ignition lines in a V-8 van I had. I got it onto the highway, the van shaking and complaining, with several warning lights on. I could barely get it to 55mph. Eventually the engine shut down and could not be restarted. Fortunately I was near an auto parts store when it stopped for good, and I managed to find two spark plug wires that worked well enough to get me home. Needless to say, MSD would not have made the slightest difference here either, as the wires were severed.)

[mnealtx 0]

>>MSD is akin to the fuel line magnets, catalysts and gas additives that proponents claim will significantly increase your gas mileage.

Yeah, but that tornado swirl thing* that you put on your intake, now *THAT'S* the real deal!!


*for the humor-impaired: YES, that was a joke!

Mike
I love you, Shannon and Jim.
POPS 9708 , SCR 14706

[souleh 0]

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But with substantially cleaner emissions. Clean Air Act, anyone?

I don't know if this has been mentioned as I haven't read the whole thread

As I understand it, if car X takes a certain amount of energy (taken down to it's simplest level, eg. joules) to make it move, to accelerate to a certain point and so forth, that is an unmovable fact of the design.

Just because you make it a hybrid and partially shift the generation of energy from the ICE to your friendly local power plant, it doesn't mean it's using any less energy. All you're doing is shifting the emissions from one place to another.

Of course, there are improvements in design associated with hybrid cars, but these aren't as amazing as people think; apply similar technology to standard ICE car designs and you'd see a reduction in emissions with those also.

It isn't just about what you're using in the here and now; our battery technology is still relatively immature and inefficient. Once one wears out, you then have the impact created through disposal. Not to mention the materials and energy involved in producing a far more complex system to start with.

Don't get me wrong, it's great to see innovation, but it's worrying to see people suddenly jump on any new "greener" technology like a fad and claim it's the cure for all life's ills.

'buttplugs? where?' - geno

[billvon 3,006]

>As I understand it, if car X takes a certain amount of energy (taken
>down to it's simplest level, eg. joules) to make it move, to accelerate to a
>certain point and so forth, that is an unmovable fact of the design.

Well, sorta. A car at a certain speed has energy that can be represented by joules; these joules have to come from somewhere. This can be reduced by making the car lighter. In addition, a car traveling a certain speed must expend X watts to maintain that speed. This can be reduced by making the car more aerodynamic.

The X watts comes (in most cars) from gasoline. The engine converts the thermal energy inherent in gasoline into mechanical energy with a fairly low efficiency (20-30%.) The rest is dumped as waste heat through the tailpipe, the radiator and (sometimes) the car's heater.

>Just because you make it a hybrid and partially shift the generation
>of energy from the ICE to your friendly local power plant, it doesn't mean
>it's using any less energy.

You are confusing two things here.

Hybrids are more efficient at converting gasoline into mechanical energy. In the case of the Prius, the engine is inherently different than the engine in a regular car; it uses the Atkinson cycle instead of the Otto cycle. This converts more of the energy in the fuel into mechanical energy, resulting in less waste heat. In addition, the regen braking function captures wasted braking energy and turns it into usable power.

Electric vehicles (and pluggable hybrids) use energy from the grid to move themselves. These are very efficient - on the order of 80%. So an EV can be 4x more efficient than an Otto-cycle gas powered car.

[idrankwhat 0]

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Don't get me wrong, it's great to see innovation, but it's worrying to see people suddenly jump on any new "greener" technology like a fad and claim it's the cure for all life's ills.

You're right, the newer technologies aren't the end all solution, but they are a step in the right direction. If we can continue to develop efficient batteries and put more power on the grid from solar, hydro and wind then each step is one towards dealing with our pollution and foreign dependency problems.
On the other hand, we also have to deal with a Congress who will choose stupid ideas like making coal into gasoline because that's what the coal lobby and their bank accounts full of "free speech" want us to do.

[souleh 0]

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Well, sorta. A car at a certain speed has energy that can be represented by joules; these joules have to come from somewhere. This can be reduced by making the car lighter. In addition, a car traveling a certain speed must expend X watts to maintain that speed. This can be reduced by making the car more aerodynamic.

Totally agree with all that - the point I was making is that these are improvements that can be applied to a standard ICE design. If we take a fixed state and simply apply 'powerplant' technologies to it, the stats required to make it do various things should remain the same.

I'll be honest, I didn't realise ICE was quite so ineffient (20-30%), so to some extent I must take back some aspects of my comment. However, what I was trying to get at more than a pure hybrid->ICE comparison, is that people fail to take into account the equivalent of a carbon TCO; it isn't all about what your car is doing in the here and now, but all the other factors involved in manufacturing, dismantling, etc.

I stand corrected though, otherwise ;)

'buttplugs? where?' - geno

[billvon 3,006]

>the point I was making is that these are improvements that can
>be applied to a standard ICE design.

Not as-is, that's the problem. A car with its normal engine replaced with an Atkinson cycle engine would be undrivable; the low end torque is nonexistent, and they idle very poorly. In a hybrid an electric motor makes up for the lack of low end torque and the engine does not usually idle, so those problems go away. In that way, the hybrid system enables the use of a more-efficient engine.

[kelpdiver 2]

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Just because you make it a hybrid and partially shift the generation of energy from the ICE to your friendly local power plant, it doesn't mean it's using any less energy. All you're doing is shifting the emissions from one place to another.

First, hybrids like the Prius don't plug in, so there's no shifting going on. Now for the plug ins, yes, but if you want to minimize pollution, what's easier: Containing the pollution output of 100,000 car sized vehicles, or one power plant? The latter isn't constrained by mass either. And it doesn't move around for its owners, so it's easy to inspect and maintain.

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Of course, there are improvements in design associated with hybrid cars, but these aren't as amazing as people think; apply similar technology to standard ICE car designs and you'd see a reduction in emissions with those also.

Corollas got 35mpg in the mid 80s. The Metro got 50. There has usually been a Honda Civic with high 30s or better as well. Lighter cars coupled with smaller engines get better economy. But most car 'advancement' in the last 20 years has been to get the same economy with more power.

As Bill says, the hybrid allows the use of the electric motor (which gets 100% of its torque always, while gas engines have a torque/rpm curve) to get back that power while still using smaller engines. I didn't even know the engine type was different till he talked about it.

[souleh 0]

Yeah it's interesting. I've learned something today. Not that I'm going to buy one of the things, heheh... sorry!

'buttplugs? where?' - geno

[quade 4]

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Corollas got 35mpg in the mid 80s. The Metro got 50. There has usually been a Honda Civic with high 30s or better as well. Lighter cars coupled with smaller engines get better economy. But most car 'advancement' in the last 20 years has been to get the same economy with more power.

This is, of course, out of necessity. Cars today weigh as much as half a ton more than they did 20 or so years ago; not because people want heavier cars, but because people have wanted and the government has mandated safer cars. And when I say safer, I mean it in the fashion of "I got mine, screw you" safe for the occupants of THAT vehicle and not anyone else.

Today I rode to work possibly one of the most enegry efficient and technically advanced vehicles designed in the last 10 years. It achieves an efficiency rating of 1.35 Miles per Mega Joules. The Prius gets around 0.34 M/MJ.

That said, it is clearly not the safest.

Everything is a tradeoff.

quade -
The World's Most Boring Skydiver

[1969912 0]

So does the Prius engine work like this:

http://www.keveney.com/Atkinson.html,

or is it just a normal engine fitted with a special profile on the intake cam lobes?

"Once we got to the point where twenty/something's needed a place on the corner that changed the oil in their cars we were doomed . . ."
-NickDG

[billvon 3,006]

>or is it just a normal engine fitted with a special profile on the intake cam lobes?

It's a normal engine with a variable offset on the intake cam, controlled by the engine computer. It allows rejection of some of the charge, effectively increasing the expansion ratio of the cylinder.

[sundevil777 102]

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Electric vehicles (and pluggable hybrids) use energy from the grid to move themselves. These are very efficient - on the order of 80%. So an EV can be 4x more efficient than an Otto-cycle gas powered car.

That is an improper comparison. An electric vehicles efficiency also suffers from the losses in power transmission, getting it into your battery and back out to the electric motor that finally makes the car go. If you want to evaluate the relative enviro-friendliness of both the Otto and electric powered vehicles, I would think that would also require the evaluation of what it takes to get the oil/coal/natural gas/whatever to the powerplant and what it takes to get the gas to the local pump. If all you care to evaluate is the relative cost, that is of course much simpler to figure.

People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

[billvon 3,006]

>An electric vehicles efficiency also suffers from the losses in
>power transmission, getting it into your battery and back out to the electric
>motor that finally makes the car go.

Correct. That's where the 80% number comes from. Battery/electric motor drivetrains are quite efficient.

> I would think that would also require the evaluation of what it takes to
>get the oil/coal/natural gas/whatever to the powerplant and what it takes
>to get the gas to the local pump.

That is a figure of merit called the well-to-wheels efficiency. Some numbers (note that all numbers are in meters traveled per megajoule pumped out of the ground)

Honda CNG (compressed methane) car: 320 *
Honda fuel cell car: 350 **
VW Jetta Diesel: 480
Honda Civic (gasoline): 520
Toyota Prius: 560
Tesla electric vehicle: 1140

* = lots of losses due to compression
** = losses due to hydrogen creation from oil

[sundevil777 102]

Why do you think the gasoline Civic does so well, when it gets lower mpg than a VW diesel? I would think diesel fuel would require less energy to refine, and benefit from that also.

Why do you think the Prius has such a small advantage?

People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am

[billvon 3,006]

> Why do you think the gasoline Civic does so well, when it gets lower mpg
>than a VW diesel?

Diesel fuel is much higher in energy content than gasoline.

>Why do you think the Prius has such a small advantage?

Because it's basically a very efficient gasoline powered car. A pluggable hybrid (next step) would be much better.

[quade 4]

Quote

Honda CNG (compressed methane) car: 320 *
Honda fuel cell car: 350 **
VW Jetta Diesel: 480
Honda Civic (gasoline): 520
Toyota Prius: 560
Tesla electric vehicle: 1140

* = lots of losses due to compression
** = losses due to hydrogen creation from oil

Gotta reference for those numbers?

I'm curious about some other vehicles.

quade -
The World's Most Boring Skydiver

[sfzombie13 324]

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when you mix vegatable oil with a couple of things, you get biodiesel and the only emission is water.

Only Hydrogen has that characteristic.

now i may not be a chemist, but when i was researching biodiesel, i read about how to make it. i found in several places that when you use vegatable oil for fuel, you need regular diesel fuel to start the engine and then you can run it off of veg. oil. if you wanted to run it off of veg. oil only, you mix it with lye and something else(it's been over a year and the memory doesn't retain unused info that long), then skim off the by-product leaving you with biodiesel that you can use without modification to the engine. The sources i used(one was discover magazine) were reputable, and all of them stated that the only emission was H2O(water). now, i may have believed info without first testing it, but as i have since dropped the project, felt that testing was not needed.

_________________________________________
Si hoc legere scis nimium eruditionis habes

[1969912 0]

Whatever chemical elements are in the fuel before it's burned in the engine will be present in the exhaust. Biodiesel (vegetable oil) is a hydrocarbon (contains, at a minimum, Hydrogen and Carbon), so Carbon will be present in the exhaust. It doesn't matter how much it's treated, it will still contain element(s) other than Hydrogen and Oxygen.

To produce an exhaust gas containing only H2O (disregarding atmospheric gases present in the combustion air), the fuel can contain only Hydrogen and Oxygen, and since Oxygen is present in combustion air, is is not necessary that it be present in the fuel. Hydrogen is the only fuel that will result in a H2O-only exhaust.

"Once we got to the point where twenty/something's needed a place on the corner that changed the oil in their cars we were doomed . . ."
-NickDG

[billvon 3,006]

>if you wanted to run it off of veg. oil only, you mix it with lye and
>something else . . .

You mix SVO and sodium methoxide, which is lye mixed with methanol. You end up with biodiesel plus glycerin (used in soaps.)

>and all of them stated that the only emission was H2O(water).

Biodiesel is composed primarily of esters, which means you have carbon, hydrogen and oxygen in the fuel. The hydrogen and oxygen turn into water, but the carbon has to go somewhere; the engine doesn't 'store it up' or anything. Generally this means that carbon dioxide or soot (pure carbon) is released. Since soot is a particulate pollutant (and what makes some diesel exhaust black) most engines are designed to convert all carbon to carbon dioxide.