Vapor Carburetors and the likes.

[RustyLugNut]

This is just a thread to continue the discussion of vaporized gasoline in internal combustion engines.

Here are two links to two devices that reached a certain level of development and scrutiny.


Clackamas engineers' invention improves fuel economy | OregonLive.com



Here is the Smokey Engine from Hot Rod:

What Ever Happened To Smokey's Hot-Vapor Engine? - Hot Rod Magazine

[sarguy01]

I could see a hot vapor system working. But, I think the biggest issue is the emissions. The other big issue is this system running in cold weather or during a cold start. Will it work when the engine is cold or will it switch over to hot vapor once the engine has warmed up?

I guess the other issue I saw is the test engines used forged pistons, rods, and heavy duty rings. That could be an issue if this system was ever sold as a retrofit. The cost of the system and then upgrading an engine could get very, very expensive.

Thanks for sharing.

[elhigh]

Boy, I remember those articles. Pop Sci did a big piece on Yunick's engine - he called it the Adiabatic Stage II, and he projected development that would necessitate Stages III and IV - and they asked the same questions my dad and I did: how the hell does he get it to run reliably without melting?

My dad even had this to say: "You don't usually see temperatures like this without it being a jet engine." Dad's not an engineer, he's a psychologist. But he reads a lot, and I read a lot of what he did. He was right. And now of course we see jet engines that run even hotter, and they use exotic monocrystal turbine blades, ceramic parts, etc. They're damned expensive but screwed into machines that generate millions and millions of dollars over tens of thousands of hours of runtime so the cost is justified. If we could bring the per-piece costs down, we could have some of those esoteric parts in our cars.

Smokey described his vision of the Stage IV as not even needing a radiator. That captivated me more than anything else he said in the entire article. If we could stop throwing heat away, we could use it productively instead.

Then I remember the other side of the coin, the old Shell Mileage competitions. They usually looked like velomobiles with engines in them, and they would mosey along at a brisk jogging pace, and the engine would fire every thirty feet or so. Often the engine was tightly wrapped in insulation to keep from throwing heat away. "A-ha!" I thought. Heat conservation again.

But NOx production becomes a thing above certain temperatures. Dang it.

Nice little blast from the past. I'm pretty sure that raising internal temperatures is a big, wide open door to increased economy but there are tradeoffs. I'm not familiar enough with the chemistry of internal combustion to say what happens, but is there something we could do to minimize NOx production? A sort of gasoline oriented DEF, for instance?

Sorry, I'm probably opening myself to flaming for that. I don't even own a diesel and I hate DEF-dependent engines just on general principle.

[user removed]

The principles are good, but I think transonic has it right. Super critical liquid fuel which is injected directly into the combustion chamber. A couple hundred atmospheres of pressure and 450 degrees F tempertature. The fuel then auto ignites with compression only once the engine is warmed up. Spark ignition is necessary for the intitial startup.

Exhaust emissions need no aftertreatment to pass even more stringent future standards, because the real issue, which is homogenous mixture at the point of combustion, has been solved, which makes the actual combustion of the mixture to occur at the same instant throughout the combustion chamber.

With modern injection you can make multiple injections, even in the milliseconds when ignition of the mixture occurs, Inject the fuel while combustion is in process in stages to actually change the peak pressure point while making "knock" or preignition impossible as well as eliminating peak combustion chamber pressures.

The concept was good 40 years ago, but the technology had to catch up with the concept.

regards
Mech

[Cobb]

Whats interesting is no one since then has duplicated the experiment. Not even a chinese clone for sale on ebay? The Chinese are selling clones of Honda IMA batteries, but not vapor carbs?

[Superfuelgero]

Originally Posted by elhigh

they asked the same questions my dad and I did: how the hell does he get it to run reliably without melting?

Put simply:
Fuel = Heat
Less fuel = less heat rise
Heat rise to a total net cylinder temp is needed to reach the melting temp.

In the racing world:
More air/fuel = More power
More power = more heat rise = melting parts.

Here:
Heated air/fuel = Less power = less effective displacement = Less heat rise
Less heat rise = the Higher the intake charge can be to net the same end temperature.

It gets a lot more complicated than that, but this is a simplified version for a psychologist.

1963 Chrysler Turbine: Ultimate Edition - Jay Leno's Garage - YouTube Info starts around min 13, but a fun video to watch.
Some light reading.
Regenerators generally
In use
Honda
More technical
Even more technical

[RustyLugNut]

As many of you have already surmised, it is a complex situation.

Some of the hints are a need for certain temperatures to occur, the recognition that complex combustion radicals could be in play and the increase in flame speed even with the relatively lean air:fuel ratios.

And I agree with Old Mech, this is just waiting for modern technology to catch up.

[RustyLugNut]

Originally Posted by sarguy01

I could see a hot vapor system working. But, I think the biggest issue is the emissions. The other big issue is this system running in cold weather or during a cold start. Will it work when the engine is cold or will it switch over to hot vapor once the engine has warmed up?

I guess the other issue I saw is the test engines used forged pistons, rods, and heavy duty rings. That could be an issue if this system was ever sold as a retrofit. The cost of the system and then upgrading an engine could get very, very expensive.

Thanks for sharing.

Once the engine is producing enough heat only then can the adiabatic system start operating.

Also, the emissions are considerably reduced if the correct parameters are met.

I feel the heavy construction of the engine was due to the "full power" capabilities Smokey built into the engine. The Clackamas system is a retrofit onto a Ford F150 that sees only a 30% efficiency gain but without the extreme heat and pressures the Smokey engine is capable of.

[RustyLugNut]

Originally Posted by elhigh

Boy, I remember those articles. Pop Sci did a big piece on Yunick's engine - he called it the Adiabatic Stage II, and he projected development that would necessitate Stages III and IV - and they asked the same questions my dad and I did: how the hell does he get it to run reliably without melting?

My dad even had this to say: "You don't usually see temperatures like this without it being a jet engine." Dad's not an engineer, he's a psychologist. But he reads a lot, and I read a lot of what he did. He was right. And now of course we see jet engines that run even hotter, and they use exotic monocrystal turbine blades, ceramic parts, etc. They're damned expensive but screwed into machines that generate millions and millions of dollars over tens of thousands of hours of runtime so the cost is justified. If we could bring the per-piece costs down, we could have some of those esoteric parts in our cars.

Smokey described his vision of the Stage IV as not even needing a radiator. That captivated me more than anything else he said in the entire article. If we could stop throwing heat away, we could use it productively instead.

Then I remember the other side of the coin, the old Shell Mileage competitions. They usually looked like velomobiles with engines in them, and they would mosey along at a brisk jogging pace, and the engine would fire every thirty feet or so. Often the engine was tightly wrapped in insulation to keep from throwing heat away. "A-ha!" I thought. Heat conservation again.

But NOx production becomes a thing above certain temperatures. Dang it.

Nice little blast from the past. I'm pretty sure that raising internal temperatures is a big, wide open door to increased economy but there are tradeoffs. I'm not familiar enough with the chemistry of internal combustion to say what happens, but is there something we could do to minimize NOx production? A sort of gasoline oriented DEF, for instance?

Sorry, I'm probably opening myself to flaming for that. I don't even own a diesel and I hate DEF-dependent engines just on general principle.

People mistakenly think that at 2300 deg C you automatically see a large production of NOx. However, another condition to the formation of NOx is time - if the combustion and pressure are held for only a short period, the "lazy" rate of formation of NOx means it can be minimized.

This is how HCCI engines can have low NOx output even with high combustion temperatures. The rate of combustion is so high and the pressure fall off ( RPM ) can be monitored that little NOx will be formed.

[maxc]

Here is my fuel vaporizer. Needs more work,money,time, project on hold.