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Old 01-11-2017, 08:46 PM   #91 (permalink)
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With super heat engines you are going to produce quite a bit of waste heat. That's all there is to it.

The problem with gas engines is their thermodynamic cycle. You have isobaric intake losses right away on the start of your cycle. Then with heat addition you are using constant volume heat addition. In theory you add all the heat at top dead center, but we know that doesn't happen.
In theory a gasoline engine can only be a maximum of about 50% efficient.
Institutions have spent millions of dollars trying to achieve this and still the closest they can get in the lab doesn't really get close to maximum theoretical efficiency.

If you think you can best the lot of them I say go for it.

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Old 01-11-2017, 10:33 PM   #92 (permalink)
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I suspect they have done it but are not allowed to use/sell it.

So yes I may not best them BUT I think I can get such a system working and share it with a few others...

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Old 01-11-2017, 10:56 PM   #93 (permalink)
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I suspect they have done it but are not allowed to use/sell it.
I swear that if even a single one of those lab technicians removes their tin foil hats for even 25 seconds....I'll be able to download the information myself directly from their sinusoidal brain wave patterns and build that engine myself. But they NEVER take off their hats!!!




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Old 01-11-2017, 11:30 PM   #94 (permalink)
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The main thing they can build but not sell is lean burn engines because the Ethanol Production Agency (the EPA) decided NOx is the root of all evil and must be eliminated at all costs.
Lean burn engines produce a little more NOx get a lot better fuel milage.

So what do you think will make the gasoline engine super efficient again?
An air fuel mixture that detonates near top dead center?
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Old 01-11-2017, 11:54 PM   #95 (permalink)
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A common mistake is to use the exhaust heat to vaporize the gasoline, this fails because ones the ICE IS on vapor it cools down cutting the exhaust heat and the car stalls.
I think I've gotten my head wrapped most of the way around the idea, but I'm still parsing the above sentence.

It seems like reclaiming waste heat from the exhaust would be a no-brainer in boosting efficiency. So why would it stall? Is the fuel that effective at sopping up exhaust heat? Or is it because carburetors were involved and you can't control the mixture dynamically?
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Old 01-12-2017, 12:03 AM   #96 (permalink)
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Wow, there's a ton of knowledge and large pile of sarcasm in this thread. Even some BS. Makes it fun to read.

Gasoline vs. Propane: Energy Density is the amount of energy that can be released from a given volume or mass. Gasoline is actually quite high, which is one of the reasons it's been the fuel of choice for so long. Propane and Hydrogen have a much lower energy density. In practice, when you mix the low energy density fuels with the appropriate amount of air, there are limitations for output.

Heating the air means you'll get less air into the cylinder each intake cycle, which effectively acts to throttle the motor. When I say "throttle", I'm referring to whatever is used to reduce air volume to the point where the vehicle runs at the speed you want. It takes energy to suck air through a tiny hole. Try breathing through a soda straw while exercising, and you'll slow down too. Changing A/F to 16 (as mentioned) has compounding effects of lean burn with effectively reducing throttle losses.

Pumping losses are actually a huge portion of the "effective" loss of a motor. The creation of heat that must be removed by airflow or radiators has been mentioned, and that's big too. Old school rules of thumb say 1/3 of the energy went to heat, 1/3 went to throttle losses (pumping losses) and 1/3 to mechanical energy that drove the vehicle. It's not that simplistic, but you get the idea. AND, that matches the 30% - 40% numbers thrown around in this thread.

The problem is we want to accelerate the vehicle which takes much more power than steady state, so the engine has to be capable of that. However, when cruising, it means we have to feed it less, which traditionally means to throttle it more, which means increasing pumping losses while cruising on the highway.

Diesel has a lower energy density, but can actually get higher "mileage" in part because they usually pair it with a turbo (compressing air to jam more in the cylinder -- effectively increasing it's energy density) and it doesn't have a "throttle" like a typical gasoline engine -- therefore reduced pumping loss.

Lean burn? Yeah, Oil_Pan summed that up.

In all your examination of the vapor vs. liquid fuel, keep in mind there is a lot more going on in an engine than initially meets the eye.
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Old 01-12-2017, 12:36 AM   #97 (permalink)
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I suspect they have done it but are not allowed to use/sell it.
Having worked for one of the big 3, I can tell you that's not true. Even if you pushed it to mean that it violated emission laws so they couldn't use it. You can certainly do better with fuel mileage by ignoring all emission conditions. You can do even better if you're willing to drastically sacrifice driveability (like 0-60 in the 1 minute range). It all depends on what you want.

Maybe if you changed the statement to say "... but won't build it because it wouldn't be driveable or wouldn't pass emissions laws."

Even with that said, I'll echo the question: What are the limits if emissions be damned?

I like air, so I wouldn't support it on a large scale, but I sure would like to know.
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Old 01-12-2017, 12:50 AM   #98 (permalink)
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Well I just may understand it better than you think. Only 30% is making POWER, that is burning and expanding during the part of the cycle that can put power to the crank, and that is about 70% of the down stroke of the piston from top dead center.

Granted another 40/50% is still burning though bottom dead center and during the returning up stroke of the piston and though the exhaust cycle and still burning on its way out the exhaust port, pass the exhaust valve and into the exhaust manifold.

Which is one reason ICEs get so damn hot the exhaust temps can run in the 1000s of degrees and the exhaust manifold runs very hot.

I have seen test bench runs of an ICE at full throttle where the manifolds and exhaust pipes can glow bright red with the heat.

NOW IF we can supply pure vapor it is said it will not need any lead time (zero advance timing) and will burn very fast and will have produced power for the 30% of the real power stroke and be completely burn out at that point. This very fast burn of only the 30% of fuel in the 30% of the real power stroke from top dead center to say 75% of the down stroke can produce just as much power with no left over waste of burn fuel.

SO if you get the same power with fast burning vapor you only need say 30% so you get much better MPG by not using the other 70% of normal fuel use/waste.

GET IT???
The can get that hot at WOT or basically making a ton of power, but just putting around as any vapor carb out there does, they don't get that hot. You want to build a motor that can't make much power, runs cool and lean with ATDC timing, you can do it without any magic cracking of the gas. You still are going to get heat and friction losses. You are also going to have emissions higher than allowed by Big Brother. You create a market for 30 hp cars, and then allow the makers to tune them for economy, emissions be dammed, and you will get better results then any vapor carb out there.

Smokey Ynick had the best most thought out setup out there but it ended up being the exact opposite of what you say. It had insane internal temps apparently. I bet the reason it never really saw the light of day was it ate itself up in sort order, or was completely full of exotic high dollar parts. Basically compared to other super high dollar exotic built for one purpose motors of the day, like say formula 1, a joke in comparison. His only claim on economy way "up to" 51 mpg which is pretty shady claim. My 454 Suburban got "up to" 51 mpg, heck it got "up to" infinity if you just shut off the motor once at speed.
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Old 01-12-2017, 01:11 AM   #99 (permalink)
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As far as pumping losses, there are gasoline engines out there that don't run a throttle, or if they do it's only as a backup for shutdown. They get really good power and economy by doing the supposedly worst thing possible, adding liquid gasoline directly into the combustion chamber and the last possible moment. Still the fuel vaporizes and is burned, just like if you vaporized it 10 days in advance, put it in a special tank and then used it to run your car. Vaporised and atomised are the same thing. Vapor-a substance diffused or suspended in the air, especially one normally liquid or solid.
"dense clouds of smoke and toxic vapor" synonyms: haze, mist, steam, condensation, moisture.

The only reason an ICE works is because of heat. You heat the air, it expands, and moves a piston. To eliminate the heat, eliminates the expansion, and no power is made. Once you use the heat it is now a waste product. You could use it for something else but it is not useful to make power in an ICE again as you need to start cold and go hot or you don't have expansion of the air. If you had some other type of fuel maybe preheating would be useful, say in a steam turbine. But that is the beauty of gasoline. It doesn't need to be preheated to be used.

I still say the best example is propane. There is nothing magical about vapor.
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Old 01-12-2017, 10:48 AM   #100 (permalink)
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Smokey Yunick hot vapor engine

Google this: What Ever Happened To Smokey's Hot-Vapor Engine? - Hot Rod Network

You might need to re-build your internals to handle the compression and heat - the ideal piston/cylinder head, cylinder liner would be nodular iron for ultra low heat transfer, although you might be able to get away with just a ceramic coating on the piston head and cylinder head - you would want to use a bowl shaped piston head like in modern direct injection diesel engines in order to contain as much heat inside the combustion chamber as possible, and you might need to use Total Seal compression rings to contain the increased pressure without having ring blowby.

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