Looks interesting but makes no sense. How do you get more power by turbocharging and heating, rather than cooling the mixture? Most everyone knows that you have to add an intercooler to a turbo to maximize power and efficiency. Volumetric efficiency goes out the window. The way to increase the efficiency of an otto cycle engine is to increase the compression ratio and/or increase the temperature delta, basic thermodynamics. Where is the independent documentation that this thing actually worked as claimed? It is easy to fool the public with a famous name and some scientific-sounding mumbo-jumbo.
I remember reading the article years ago, but my fuzzy memory thought it was Carroll Shelby that was doing this. I always wondered why I didn't hear any more about it. Made me think those "big oil companies bought it and hushed it up" conspiracies that I always laugh at might be true. The theory behind it might have some validity, though. After all, gas vapor is what burns. This thing is converting all of the liquid fuel to vapor, before it enters the combustion chamber, possibly allowing a more efficient burn. The turbo is obviously providing a little boost, which would help the power. The cars he was using in the article I read were Omni's with the 2.2 4cyl. ALL engines of the era were pretty low compression. I forget what power boost he claimed, but they were supposedly getting near 60MPG's. That's not too far-fetched. Light cars with overdrive trannies, and barely over 2 liters. It would still take a significant boost in efficiency to do that AND improve performance. Engines aren't very thermally efficient, and anything that could reclaim that "lost" energy would be good in both economy and ease of cooling.
The whole idea behind almost all current thinking, especially forced induction, is to cool the intake charge. We want to do this to keep the air denser, and therefore pack more into the cylinder. Getting enough AIR in is the goal. Getting enough fuel in isn't the problem. We can jet a carb or program EFI to run too rich if that's what we wanted to do. Keep in mind the head-porting idea of not polishing the intake side to a mirror finish, because the rougher walls help KEEP FUEL ATOMIZED. Why is this a concern if it's all gonna burn anyway? Because it may not all burn. Think of what a catalytic converter does -- burns unburned hydrocarbons. Many vehicles with cats removed have that rich exhaust smell, even with EFI supposedly keeping the mixture "perfect". Why have dual spark plugs, or MSD ignitions? Same reasons: trying to burn all of the fuel. Port injection fires the fuel right at the port so the intake runners can be designed for the best airflow, because we no longer have to worry about keeping the gas in suspension in the intake. Turbos use intercoolers to cool the air charge, but a draw-through system can't use it, because of the fuel dropping out of suspension as the mixture cools. In essence, this is what Yunick's system does. It is a turbocharged engine with a draw-though system, but it sounds like he was keeping the turbo outlet close to the intake ports so that it didn't have time to cool off. This forced in the homogenous mixture, that due to being superheated, was already "halfway there" on combustion before it ever gets compressed and lit. This releases more of the "lost" energy of unburned fuel. More efficiency means both more power and more mileage. Perhaps he really was onto something with this, but everybody missed the boat. He was using carbed engines, but at about the time that EFI went full tilt on everything.
I believe all of GM's cars were EFI by this time (1984), as well as most Fords. Everything that wasn't then was within 2-3 years. Since then, things went to port EFI, except GM holding onto TBI for quite a while. This would preclude the use of such a system, although I can't help but wonder, if it worked, then TBI would be the thing to use, as it offers more precise mixture control and timing control as well, but would basically work just like a carb on this system. Man I wish I had some money. I'd start experimenting, now that I've seen this again and remember how the system was set up. :-)
__________________ People who say "violence never solved anything" obviously slept through history class.
The turbo had one job, to force the fuel mix in the right direction into the cylinders. It was so hot that without the turbo the mix started backing out of the manifold due to expansion from heating.
The first engine was a v-twin made from the front two cylinders cut off from a Buick v6 block, with a Rochester 2 bbl carb. Later versions used a throttle body injector. There were also other types of engines, like in-line 4s later on, I think.
I have seen some info on this engine over the years. If I understand it right the problems were with the materials they had to work with. Someday it may be possible to operate the IC engines at much higher temperatures but not yet.
"Beam me up Scotty. There's no intelligent life down here..."
The heat vaporizes the fuel for more complete combustion. It also means more of the heat from combustion goes into making the piston move instead of relying on some of the heat to vaporize the fuel before it burns.
I have been hearing about that system for a long time, but that's the first I've seen for diagrams. It would be nice if more of the links worked, though. I bet that engine would warm up far faster than a modern engine, but it would need better oil than we have available today.
Real trucks have the key on the left FTE Guidelines
Originally Posted by tjc transport
but i can't tell you where i am, i don't want the nice men in the white suits and hug me jackets finding me
This adiabatic idea has been bouncing around the turbo world for decades. I've heard of people building 1000hp+ Porsche turbo engines that run all day at peak output, with no cooling system etc. I haven't seen the car, I haven't seen that engine at the race track, or the drag strip and the guys that get on forums and claim to have these wonder-donks never seem to get on paper with raw results.
I'd seriously be first in line if such an engine were possible. Maybe it is. Some of the core concepts are utterly true and commonly applied in race engines (controlled flame-front, stoichiometric yada yada) but I wish I could get to the root of these rumours and find someone running an adiabatic power house.
I guess it might work, though, if the boost were kept low enough, and the compression ratio were kept low enough. Both could be accomplished with a very small turbo. The whole theory of this thing violates the reasoning behind fuel octane rating though.
The only thing I'd be afraid of, is the turbo impeller getting hot enough to ignite the fuel mixture, since it is a draw-through system. Once that happens, say goodbye engine!
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