10 replies to this topic

[C F Eick]

In the mid-80s I was reading a Swedish car magazine that had regular reports from the USA, mostly drag racing and Nascar. One series of articles was about this guy called "Smokey" Yunick, apparently a legendary engineer/constructor in the Nascar scene. He had developed something he called Hot Vapor engines. They produced incredible power/cui and torque/cui ratios and at the same time had extremely low fuel consumption. I don't remember the articles exactly but there was talk about world patent and that the large car manufacturers were extremely interested in his work. The article writer, a somewhat enthusiastic man, foresaw 2- or 3-cylinder engines with 3-speed (manual) gearboxes in the future. The small engines would produce the same power as today's(1985's) large engines and the torque would make 5- and 6-speed boxes unnecessary. The fuel consumption would be half of 1985's engines and so forth.

Well, the years went by and I never heard anything about Hot Vapor again. In 1995 I talked with an engineer who at the time was responsible for Volvo's engine development and the only thing he knew was that the Hot Vapor concept only worked when high-octane(103+) fuel was used.

Does anybody know something about this? Whay exactly was Hot Vapor? I'd love to know what happened. Is Smokey Yunick still alive? He was in his mid-60s 15 years ago so...

/C F Eick

[EddieJF1]

I'm pretty sure he's still alive. I think he was just at some banquet, according to Autoweek (I think there was a picture of him on the last page).

[Ray Bell]

Like you, I saw these articles, perhaps in the early seventies, and then nothing since. I've even forgotten what the concept involved.
Anyone know?

[tak]

I too have some fuzzy memories of the "hot vapor engines". I think part of the attempt was to run everything hotter to improve thermodynamic efficiency. If memory serves, it was fundamentally a turbocharged engine with no cooling. The odd thing that sticks in my mind is that he was putting fuel in before the turbocharger. I don't remember why (better mixing or charge cooling perhaps?). If we're talking about the same articles, I believe there were some significant material property and lubrication issues related to no cooling...

[Ray Bell]

Was there an article about it in Popular Mechanics?
Or is that not the right magazine?
I remember also an article about a converted mid-fifties Dodge with induction swirl induced that made huge differences to performance and fuel requirements (ran on kerosine, I think).

[desmo]

Apparently the idea died a natural death. I don't believe there are any workable, practical technologies out there that are superior to what we all use. X-Files type conspiricy thoeries aside, if they were really better they would have been used.

[Griffon]

Smokey's web page: http://smokeyyunick.homepage.com/

There is a link to send e-mail.

[C F Eick]

Thanks Griffon!

[Stenis]

The idea of the Hot Vapor engine was to utilize as much of the energy in the fuel as possible. In an ordinary four-stroke spark-ignited engine about one third of the energy of the fuel is wasted through the exhaust gases, one third goes to the cooling system and one third actually can be taken out from the flywheel. That is: About two thirds of the energy is wasted. By using this energy that is usually wasted to heat the incoming fuel and air mixture there will be less energy wasted. Usually you want the incoming charge to be as cool as possible since gases expand when heated (and the volume of the cylinder is constant) but by having a turbo in the system that builds up some pressure the mass of the charge will not diminish. Smokey preferred to call the turbo a 'homogenizer' since the revolutionary idea of the Hot Combustion engine was to homogenize the fuel and air mixture so that it would not ignite already in the intake manifold.

Smokey has always been good at promoting his ideas but it seems the Hot Vapor engine never made it. On reason for sure is that Smokey did not have any exhaust emission measurement equipment and did not consider the oxides of nitrogen NOx produced in such an engine. NOx is formed at high temperatures and although the catalytic converter dissolves most of the NOx I still believe that the Hot Vapor engine would have trouble passing the exhaust emission laws of today. I have also heard rumors that the engine was not more efficient than an optimized standard engine but that is only rumors. It also seems likely that it would only run on high-octane gasoline.

I assume you are talking about an article in the Swedish magazine Bilsport from around -84-85. It was a good article and it deserves to be read over and over because there is really a lot of information there. Hot Rod also had an article bout the Hot Vapor maybe in -85.

I am still one of Smokey's greatest fans and I still think the Hot Vapor concept is very interesting indeed and perhaps with a little more development maybe....

[F1Rulz]

Ahhh... this brings back some memories. I remember in high school a buddy of mine just got a '67 El Camino (was it 67, well it was the first w/ the Chevelle front end), 327, Holly,... You could chirp the tires in that sucker in 2nd gear . Anyways I remember he checked out some books from the library, a couple of them were written by Smokey. I even think I remember him going on about this very topic. Funny.

[Ray Bell]

I thought 327s were well dead by 1967?
They ran as hot vapour engines in F5000 quite often...