Dimitri,
Engine efficiency (the mechanical efficiency) is not fixed. It varies with compression ratio and fuel burn rate, among other things. That is why two identical engines using identical fuel but one engine with higher compression will get more power and better mileage. With alcohol you can increase compression pressures well above what gasoline will tolerate and the engine runs cooler (less heat waste) than with gasoline. Running alcohol 80% and 20% water provides even more power than straight alcohol (latent heat content) and burns slightly leaner mixtures than straight ethanol. Putting more fuel into combustion is puting in more liquid so it expands more creating more impulse and the water takes some of the heat and adds more to the impulse in its conversion to super-heated steam.
If you place a liquid into the combustion chamber and let the heat of combustion vaporize it then you get more power because some of the heat normally lost to cooling and exhaust temps is used to add mechanical power to the engine. That is to say it uses wasted heat to add mechanical power.

Your article on the "sunchokes" was using only the tubers but if you grow the jeruselam artichoke (not the hybrid) you don't use the tubers - you use only the parts of the plant above the ground - like sugar cane - and leave the tuber in the ground. In grows well in even poor soil fixating nitrogen to improve the soil. The tuber stays in the ground and you get two yields per year. This process yields material to make 10000+ gallons of alcohol per year on only 5 acres of land. The by-products of making ethanol are top grade fertilizer and more high protein feed for livestock than the parent material. (whether it is corn, sugar cane or jeruselam artichokes)

I am not saying that the USA could replace their gasoline usage with ethanol - its not possible but if I had five acres of land to use I could be gasoline free with my own cars as long as I didn't travel more than 1/2 tank from home - limiting travel to about 300 miles away with a 33 gallon tank.

Remember that efficency changes when you use the heat that is normally lost in the IC engine to turn liquid into mechanical power. Raising the compression also raises the efficency because it generates higher temperatures in the combustion process which expands the gasses more than a lower pressure.

When NASCAR switched to ethanol they still made over 800 hp with 350 cu" engines (without changing compression). They use more fuel because they aren't allowed to use the 14:1 compression that is ideal when using ethanol. They aren't using pure ethanol it is treated with 5% gasoline for denaturing. As a private individual licensed to make 10000 gallons for fuel use I don't have to denature the alcohol so I can mix it with 20% water (160 proof) and get more push on the piston while burning less fuel.

I don't believe that there is an answer to the limited supply of fossil fuels other than changing over to electric but that will require an entire change from IC engines to electric and supporting that with non-fossil fuel electric generating plants. That means wind, solar and nuclear power plants being used to generate all the power needed in the world. To keep nuclear plants in fuel we will have to use "breeder" reactors to recycle the plutonium from waste fuel rods to make new fuel for the reators. The benifit to that is no long term storage of super-longlife radioactive waste. The downside is the public fear of plants going critical and the world fear of nuclear proliferation. (breeder reators make weapons grade nuclear fuel)

Dimitri wrote:

Geland, Even if the American's converted every acre of land that can be possibly used to farm corn, instead of all other food stuffs, they still could not meet their fuel requirements. Similar in most of the world really. It is just not practical to go for biofuel. Dimitri

Dimitri,
There is no way with current technology biofuel replace oil, this is a fact that every scientist would concur.
OTOH, even replacing 10% would mean improvement in source.

Now, I might be wrong,
the reason Lead is added on fuel is to retard the combustion, thus increases the "efficiency" of pure gasoline.
Ethanol is a slower combustion fuel than gasoline, thus adding ethanol to gasoline, in fact increase the efficiency conversion of the fuel.

Retarding combustion actually increases energy conversion for the combustion energy delivery are thus more efficiently converted to motion.
Fast burning fuel would KNOCK the piston, where slower burner, would PUSH.
So it is not pure energy density calculation that made the difference, but also energy conversion efficiency need to be included..

Hydrogen anyone?? There is an experimental wind system installed on an island here that uses excess power to take hydrogen out of sea water and store it in tanks. When the wind isn't strong enough to meet demand the hydrogen is used to power a gas turbine generator to meet the power shortage. Reports indicate it works very well. The high initial cost is a negative factor in expanding to other locations which now rely on diesel generators.

Fuel cell technology is very mature but the big oil companies will not invest in distribution systems for hydrogen so car companies can not build cars and trucks to take advantage of this technology. It also has some cold weather challenges.

So called HICE (hydrogen internal combustion engines) with direct injection and turbo-charging look like a promising solution.
en.wikipedia.org/wiki/...ne_vehicle

Bio-fuels have their dark side also.
www.guardian.co.uk/env...tish-firms

If we were in a true free market economy I think we would see more movement in replacement motive energy sources.

Meh Radar, the problem is per mole of water, you need 286 kJ of energy at 1.48V to break it down into hydrogen and oxygen. For a perfect system, in reality your looking at 95% efficiency using expensive set ups running it at 1.55V.

When you then turn around and use the hydrogen in a fuel cell application your looking at ~53% efficiency maximum.

So now, from a peak efficiency of 95% with your production of hydrogen, to your peak efficiency of 53% in a fuel cell. Your system's entire efficiency is only 50%.

So if your producing the hydrogen and the power to move your car, for every say 48 miles you go like in my Harley example above, you will need at least double the electrical energy of 26.35MJ to get you going that far.

Which ends up needing a secondary power source on the car to make it work, or you skip the hydrogen splitting in the car, and you offload that efficiency and power requirement to a stationary source. Which allows you to not worry about the doubling of power you'd need to get you moving. Which is what they are doing in California etc.

Paul,

Engine efficiency of any internal combustion style engine, regardless of the type of fuel, compression ratios etc IS indeed fixed to a theoretical maximum of 37%.

Engines regardless of the fuel source today, even with our best and latest tricks (such as Ford's Ecoboost) still are only just reaching the 20% mark of efficiency.

There are too many losses due excessive heat, energy that is used to move the entire engine assembly itself etc. Even if we built the prefect engine today we'd only hit 37%. Which is why for hydrogen manufacturers are going towards fuel cells because it offers a peak efficiency of 60% according to the theoretical limitations instead of trying to directly burn it.

Geland,

And what happens to our food prices as we already are reaching the limits of food production in this world when our population hits 10 billion by 2080?

When food starts getting to the point of being too expensive even just enough so that we may live even in our richer developed countries with all our farming technology backing us up?

We are diverting food today, but it will cause us problems sooner then later.

MacD,

While the HICE seems interesting, it promising a 20% fuel efficiency boost, from modern gas engines is only putting the efficiency from 20% to 24%. Still only half of what a fuel cell can do.

Dimitri

gelandangan wrote:

Now, I might be wrong, the reason Lead is added on fuel is to retard the combustion, thus increases the "efficiency" of pure gasoline.

And I always thought lead added to gas was an octane booster.

Your both right.

By increasing the octane through leaded gas to prevent knocking, you allow higher compression ratios which increases the efficiency of the gasoline engine.

Europe used alcohol (ethanol) to do the same thing for a while before going with leaded gas because the fuel lines get corroded as ethanol based gasoline mixes end up absorbing water. Which is why fuel systems today are all stainless/plastic to prevent that in cars designed to use Ethanol based fuels.

Dimitri

Dimitri wrote:

Meh Radar, the problem is per mole of water, you need 286 kJ of energy Paul, Engine efficiency of any internal combustion style engine, regardless of the type of fuel, compression ratios etc IS indeed fixed to a theoretical maximum of 37%. Engines regardless of the fuel source today, even with our best and latest tricks (such as Ford's Ecoboost) still are only just reaching the 20% mark of efficiency. There are too many losses due excessive heat, energy that is used to move the entire engine assembly itself etc. Even if we built the prefect engine today we'd only hit 37%. Which is why for hydrogen manufacturers are going towards fuel cells because it offers a peak efficiency of 60% according to the theoretical limitations instead of trying to directly burn it. Dimitri

Dimitri,
The standard reciprocating piston engine is only 19 - 37% THERMALLY efficient. I assume that is the value you are quoting. By injecting water into the burning fuel/air mixture you keep that heat from going into the engine or out the exhaust and instead it is used to make super-heated steam which expands some 40000 times in volume (without making pressure) or at combustion pressures it adds up to 60% of its expansion to the pressure on the piston. That adds torque and HP without using any extra fuel.
As far as mechanical efficiency goes there are a lot of things that modify the figure. Higher compression means higher presure from combustion and that means more torque from the same amount of fuel - efficiency goes up. Oxydized fuels add power - Ethanol on the low end to Nitro-Methanol onthe high end. The reason they add to the mechanical efficiency is that with more oxygen in the fuel less air is needed in the combustion chamber so it has more liquid and less gasses. As it vaporizes and burns it expands roughly 200 times from liquid to gas and then from gas to superheated gas another 200 times - that is 40000 the volume of the liquid! That is why nitro-methane delivers 4 hp per cu". That is much more mechanically efficient than the V-6 in your Honda making not more than 1.2 hp per cu" unless you add a turbo or super charger - there you add more pressure and more fuel and get a bunch of power out of it - up to 2 hp per cu".
As for economy you can do a lot to get better mileage from an ICE. I have a "Stock" (never rebuilt) Ford 302 in a 3200 pound Maverick that still gets 28 MPG on the highway. The annual average MPG for this car is 21 MPG. I can't say how much power it makes because it is a daily driver that I have never put on a dyno - but it has enough get-up-and-go to get into traffic and give me trouble trying to keep it from going over 70. This is with a three speed auto and 2.92:1 rear gears and 14" wheels.
There is also a "new" engine (finally perfected) called the MYT engine that uses air and injected water to keep it cool. (in high power applications it can also use an oil cooler) Its design allows a 8" diameter, 37 pound, 8 piston engine with only 26 moving parts to make 400 hp. It uses compression ignition (no plugs), with any fuel you wish to run. Once combustion begins water is injected and the cycles continue with no fuel until the heat is used up in the engine making steam. This engine has had testing and shown to be over 80% thermally efficient - not bad for an internal combustion 8 piston engine. The pistons only move in one direction around a toridial (? sp) chamber so there are fewer losses. He plans to try one using powdered wood as a fuel in the near future.
I understand that Russia has made a nearly identical engine and will begine marketing next year.

Paul,
you are right, injecting water into engine would increase the pressure big time, and recycling the thermal energy that are otherwise wasted, thus increases efficiency greatly.

Have actual motor with this tech been built yet? I'm talking about real production, not prototype?

I imagine you would inject water only after the engine is hot, and you would not use standard iron based exhaust for it would rust plenty quick.
And another thing, due to the thermal fluctuation of the engine, I guess a more thermally stable material need to be used on the piston and cylinder, otherwise on the first squirt, the whole thing would jam solid.

I love this forum.. we can talk about tech as well as shooting..
To satisfy the redneck element with a sprinkle of nerdyness..
And oh yeah.. free beer...

what more would a bloke want?

PaulS wrote:

The standard reciprocating piston engine is only 19 - 37% THERMALLY efficient.

The theoretical limit of 37% is of the conversion of the energy in the fuel can be converted into power outside of the engine.

PaulS wrote:

There is also a "new" engine (finally perfected) called the MYT engine that uses air and injected water to keep it cool. (in high power applications it can also use an oil cooler) Its design allows a 8" diameter, 37 pound, 8 piston engine with only 26 moving parts to make 400 hp. It uses compression ignition (no plugs), with any fuel you wish to run.

The MYT is nothing new (nearly 200 year old technology for that matter), and it still uses spark plugs for its gas versions, but they are "focusing" on bio-diesel.

One problem with them is that there is no way to adequately compensate for the vibrations and energy it gives off without using some sort of mechanical system (gear box + counter weight).

Another is the fact that sealing of any kind of engine built like this is a major PITA. Especially for a production environment that needs to be able to relatively quickly assemble them and throw them into the chassis without spending hours upon hours making sure each one is built correctly.

The MYT needs multiple gaskets just for the cylinder area, and the way its going to feed oil to the pistons is relatively dubious at best.

Really its only getting attention at the moment by different groups of people because it is different, and the patents on this style of engine are long expired.

www.google.com/patents/US2301667

As for finally perfected, I've yet to see it actually run, just trial demos running on compressed air, all show no work. Heck the line of Generators that were supposed to be out already are still not out.

At this point Raphial Morgado can claim that the exhaust is pure gold in gaseous form and it wouldn't be any more of a lie then the rest of his statements of his engine.

gelandangan wrote:

I imagine you would inject water only after the engine is hot, and you would not use standard iron based exhaust for it would rust plenty quick. And another thing, due to the thermal fluctuation of the engine, I guess a more thermally stable material need to be used on the piston and cylinder, otherwise on the first squirt, the whole thing would jam solid.

You make some valid points.

Dimitri

Any thought on the Stirling hot air engine?
theoretical conversion up to 63%
pure multi fuel, can run on gas, gasolene, diesel, ethanol, wood chips, bacon grease... Etc.
absolute tolerance to ambient pressure, can be used in stratosphere, or space with no loss of efficiency.
runs at temperature differential as low as 5 celcius (or less?)

Engines made by philips are
used in Holland for public transport bus in the 70 or 80's
NASA made one to harvest energy of sun light.
Was widely used before Diesel made his invention.

Problem with Stirling engine is that they need heat to enter the system from the outside, so you must convert something to heat then run the engine.

So if your say building a generator, having a tank of propane (or line fed NG), you burn the fuel, create the heat and the system works.

One nice thing about the ICE and the reason it won out, is that the Stirling engine is meant for when open boilers were common place for steam power, while the Stirling engine because of its inherent self regulation makes it "safer" the steam engines. However Stirling engines are still pretty big compared to ICE's with the same power rating, and they are relatively more expensive as a capital cost.

In my opinion while cool, its almost a step backwards for cars, for a back up generator for your home, I think the idea is great, but how many people want fuel burning in a effectively open flame to power their engine?

Also in a ICE its easier to insure better fuel burn to be cleaner then a open flame, so I doubt the EPA would like them. :S

Dimitri

Why not have a hybrid Stirling and electric engine?
you can run your car off battery until the Stirling is heated up then use it to run generator that recharge the batteries.

ICE hybrid has been commercialized for ti does increase efficiency, so there are no reason why ECE cannot be used.

Dimitri wrote:

PaulS wrote: The standard reciprocating piston engine is only 19 - 37% THERMALLY efficient. The theoretical limit of 37% is of the conversion of the energy in the fuel can be converted into power outside of the engine. PaulS wrote: There is also a "new" engine (finally perfected) called the MYT engine that uses air and injected water to keep it cool. (in high power applications it can also use an oil cooler) Its design allows a 8" diameter, 37 pound, 8 piston engine with only 26 moving parts to make 400 hp. It uses compression ignition (no plugs), with any fuel you wish to run. The MYT is nothing new (nearly 200 year old technology for that matter), and it still uses spark plugs for its gas versions, but they are "focusing" on bio-diesel. One problem with them is that there is no way to adequately compensate for the vibrations and energy it gives off without using some sort of mechanical system (gear box + counter weight). Another is the fact that sealing of any kind of engine built like this is a major PITA. Especially for a production environment that needs to be able to relatively quickly assemble them and throw them into the chassis without spending hours upon hours making sure each one is built correctly. The MYT needs multiple gaskets just for the cylinder area, and the way its going to feed oil to the pistons is relatively dubious at best. Really its only getting attention at the moment by different groups of people because it is different, and the patents on this style of engine are long expired. www.google.com/patents/US2301667 As for finally perfected, I've yet to see it actually run, just trial demos running on compressed air, all show no work. Heck the line of Generators that were supposed to be out already are still not out. At this point Raphial Morgado can claim that the exhaust is pure gold in gaseous form and it wouldn't be any more of a lie then the rest of his statements of his engine. Dimitri

Dimitri,
The 37% - You and I both know that the torque that an engine makes is calculated as the area of the piston times the pressure of combustion times the stroke (or moment arm). Then you remove frictional losses that remain close to the same in any individual engine. From that equation you can see that raising the compression (pressure of combustion) will raise torque. You have to admit that raising the torque has a direct influence on the HP that the engine will make. Since the acceleration of a vehicle is directly related to HP then it is safe to say that the engine with the higher compression will accelerate the car to a given speed and over a given distance faster than the engine with lower compression. Its mechanical efficiency is higher. All this is accomplished using the same amount of the same fuel.
My previous examples of different fuels shows that mechanical efficiency is not a fixed percentage and that it does vary with different fuels. You choose not to address those points but rather go back to your quoted percentage as some kind of belief that is beyond reproach in spite of the facts to the contrary. I can't argue your faith with facts and logic so after this post you can win the arguement based on your faith alone.

I have only read three articles on the MYT engine and neither of us have seen one. The prior engines never ran due to problems in the timing of the pistons and the parts necessary to make it all work. Raphial Morgado has patents on the internal changes that he has made to perfect the operation.
I for one whould love to see one in operation but it is not the only high efficiency engine out there. There are five and six stroke engines that both use water injection to produce more power and waste less heat. There are engines that use two pistons in the same cylinder to vary compression and extract more potential. There is a pure rotary engine that utilizes shock wave technology to combust fuel and others that are built using ceramics so as not to absorb heat into the engine and use the heat in the exhaust to power a turbine to generate electricity. This combination in a hybrid makes the ICE up to 70% efficient in charging batteries or adding power on demand.

This started as a thread on ethanol and you say the gains from using ethanol are insignifigant. I disagree. You say that you can't get the same mileage from Ethanol and I say that if you can make more power then you don't have to burn as much fuel to go the same distance - that is what throttles are for. You refuse to admit that the thermodynamics involved in combustion are about more that the BTUs in a given amount of fuel. You have a lot to learn unless your faith in a single statistical percentage prevents you from seeking that knowledge. If that is the case then there is no point in debating you because no amount of proof would change what you believe.
In any event be well and live life to its fullest.
Your friend,
Paul

PaulS wrote:

The 37% - You and I both know that the torque that an engine makes is calculated as the area of the piston times the pressure of combustion times the stroke (or moment arm).

In a prefect world yes, however the actual torque output of the engine, is always less then that.

Everything from the alternator, to your fan, to your bearings, coolant and oil pumps etc all eat away at that torque. There is no getting around it. Let alone the losses required to compress the engine's cylinders for exhaust stages and the compression stages so it can burn more fuel. Plus the losses that the molecules take when they form CO2 and H2O in the combustion process.

Then there is always the difference between engine's output and wheel's actual output, aka the drive train losses.

All of these losses need to be considered for any system. Even in fuel cell powered cars, your fuel cell might be that 60% efficient I quoted earlier, but your DC motors also eat away at that, as each one is only 80-90% efficient with the electrical energy you feed it. Plus the control circuitry for the power regulation and control on the car eat away at its efficiency as well. All of which would be part of the ICE's efficiency losses.

PaulS wrote:

My previous examples of different fuels shows that mechanical efficiency is not a fixed percentage and that it does vary with different fuels.

You can compress the engine till there is only a single layer of atoms left, the problem is the gas laws at that point, your peak power is the moment the fuel starts to expand, after that the pressure drops and the pressure on the cylinder head does with it to a point.

It is like your 308Win, typically burns all its powder after 19" IIRC, after that, while the pressure starts to drop, there is still some improvement in velocity to have a longer barrel. But the improvement in velocity per inch over 19" is less then the loss of velocity for using a barrel under 19" per inch.

Due to the wasted fuel energy that didn't get used to push the bullet, and the fact that as the bullet passes the point the powder completely burns, the pressure starts to drop giving less energy to the bullet being shot.

Similar with a ICE. A fuel with less joules of energy cannot produce as much energy as a fuel with more joules of energy waiting to be tapped. At least in modern normal physics, such as in a ICE.

While you can either add more powder to make the velocity increase, or you can increase its starting pressure by pushing down at the powder charge. In a ICE it is the same principle, except too much compression of the charge, if the fuel is of low energy potential to begin with your going to end up wasting more energy to compress the fuel more then you need to.

There needs to be a balance, right now the 90/10 mixtures are allowing car manufacturers to get away with more compression like with leaded gasoline because of ethanol's anti-knocking properties, but there are limitations to just how much you can compress before it becomes more wasted energy then gained.

PaulS wrote:

I have only read three articles on the MYT engine and neither of us have seen one. The prior engines never ran due to problems in the timing of the pistons and the parts necessary to make it all work. Raphial Morgado has patents on the internal changes that he has made to perfect the operation. I for one whould love to see one in operation but it is not the only high efficiency engine out there.

He can "prefect" all he wants, but the fact is not even ONE of his engines have used a real fuel source to date.

Even so, till he runs one of his engines for 100,000 miles to prove they can survive a typical automotive power train warranty period, doesn't matter how much he prefects his engine, its still useless in the automotive market.

Assuming he ever gets to the point where he uses any kind of gasoline, diesel or what have you, anything but air.

PaulS wrote:

There are five and six stroke engines that both use water injection to produce more power and waste less heat.

Considering the patents have been expired since before the Second World War, as Leonard Dyer came up with it in 1915, if it was that great it would already be on the market.

But dumping air into your cylinders causes such a problem for maintenance due to rusting etc, that the alternative materials to use for engine production simply costs too much to build a engine commercially using them.

A R&D engine showing it off, or a prototype and getting it to the production floor are very different things.

PaulS wrote:

This started as a thread on ethanol and you say the gains from using ethanol are insignifigant.

I said the "environmental" gains of ethanol are over glorified. The difference in pollution output is too close at 6% to care about.

Dimitri

well I had a old 2 stroke chainsaw that was just the ducks nuts and cut wood like a hot knife through butter. can I buy the same model here in N.Z. (they still make them) NO I PLURRY WELL CANT!!!!!! why because of plurry environmental considerations... 2 strokes are a dirty word even outboard motors have been regulated which has lifted the price.