Last week in this post, I made reference to an ultrasonic fuel induction system that was put together by some researchers in Florida in the 1970s and tried out (and tested) on a Slant-6. I went to the downtown reference library this morning and retrieved it, photocopied it, scanned it, and made it into a PDF, which you can now download here. You'll want to zoom in/magnify slightly for easier reading.

Interesting results, with a great deal of comparison data (the same car with the standard carburetor, various then-upcoming emissions standards, various other engines, etc.). Big, bulky control gear would probably be a great deal smaller nowtimes than it was in 1972. The article claims the stock fuel pump is used, and I suppose that's possible, though to modern eyes the notion of a fuel injector (even a TBI injector) running at 4psi is more than a little bizarre.

Nothing ever became of this setup. The European auto industry switched to port fuel injection in the early '70s, the Japanese kept reasonably conventional carburetors but used fancy hardware like 3-valve-per-cylinder engines, and the domestic industry futzed with ever-more-complex FrankenCarburetors and strangulation-type emission controls on conventional engines, barely squeaking through increasingly strict emission standards with cars that ran poorly and inefficiently. Eventually the domestics went to TBI, with higher pressure but without an ultrasonic element.

Things that make ya go "H'mmm!"

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Very intriguing. I'd love to have a system like that on my Duster's slant, if the improvement in fuel economy really is that good. Makes me wonder what it did for overall performance of the engine.

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'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

H'mmm indeed! What do you suppose happened to that idea? My understanding is that with the current principals behind gasoline internal combustion engines, with the fuel being burned as an atomization instead of a vapor, we get only about 10% of the latent energy in the fuel. It does seem we could be doing alot better here.

The most potential comes from the idea of vaprorizing the gasoline before burning it, or better yet exploding it as deisel engines do with their fuel. The problem with that is gasoline vapor is highly explosive, and thus pretty dangerous. But, it does not seem as if anyone is trying very hard to improve this technology. Why do you suppose? Is it just lazyiness; the inertia of a huge industry that is hard to change; or some sort of conspiracy at work? Why do these ideas crop up from time to time, and then seem to die? Is there something we can learn from them?

Sam

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My guess is that with modern high pressure EFI injectors, the fuel is in as small droplets as it needs to get completely burned.

If I had to guess, I would say that we extract more like 80-95% of the fuel energy, but most of that (75-80%) goes into heat, and not driving the wheels.

Might be fun to try this sometime with EFI, but the gain they got is about the same gain you expect from switching from carb to MP-EFI. This would probably not be hard to set up with modern ultrasound transducers and electronics.

Lou

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Home of Slant6-powered fun machines since 1988

Vaporizing gasoline was the idea behind the Pogue carburetor, the multiple discharge points of the Fish carburetor, part of Smokey Yunick's "Homogenizer" for his Hot Vapor Cycle engine, and several other attempts at improving gasoline engines. There's been a lot of work in the area over the last 70 years or so - and varying success.

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"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

Well, that's roughly the amount of energy we can use to move the vehicle; most of the rest is, as Dart270 says, lost to heat.
Agreed. Many methods of doing so have been tried; most of them involve superheating the fuel/air mix. The best of these was Smokey Yunick's "Adiabatic" engine program, but even that one wasn't immune to the simple physical fact that a superheated intake charge is very much less energy-dense than a cooler charge. This notion of ultrasonically vapourising the fuel would seem to get around that problem.
Errrr...huh? That's not how a diesel engine works at all. Diesels are compression-ignition engines: Air (only) in the cylinder is very highly compressed, which heats it up, then diesel fuel is injected into the cylinder. The air is hot enough to cause the fuel to ignite spontaneously, without a spark. The fuel burns, it does not explode.
My best guess is a great deal of inertia combined with the bulky and costly nature of ultrasonic transducers and control gear in the early 1970s. Perhaps if ultrasonics had been compact and cheap at the time, this idea would've made inroads — though it is very rare for the auto industry to licence outside inventions; this is the well-known "not invented here" syndrome. It was cheaper at the time to keep adding widgets and progressively strangling engines to squeak past the Federal certification tests. By the time ultrasonics became compact and cheap — remember the sudden appearance of ultrasonic home humidifiers in the 1980s? — the domestic industry was finally moving (albeit spastically) towards fuel injection.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Perhaps...but perhaps not. What interests me especially is the comparison of baseline and ultrasonic emission levels, for it's a distinctly bigger reduction than seems likely to be achieved by swapping the 1bbl carburetor for a production-type TBI system without closed-loop operation or catalytic converter. I would've liked to have seen emission test results for the system without the ultrasonic element operating, but the article says "Tests have also proved that the engine will continue to run in case of failure in the sonic device. You simply lose the fuel savings and the clean exhaust until a repair has been made."
Yup, I agree, I think the economy and exhaust cleanliness improvement they got with the ultrasonic TBI is comparable to that obtained by changing from carburetion to MPFI.
Agreed. The hardest part, I think, would be fabricating the hardware.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

If this could be done for a reasonable end cost (compared to the approx. $1,000 for a full EFI system), and with only a small amount of fab work (I'm thinking just a matter of drilling and tapping a large single barrel carb or a throttle body that could be put on either a Hyper Pack intake or a Super Six intake. I would think a Hyper Pack intake would be best), it'd be a great way to net some better economy and environmental friendliness out of our engines. I'm still very curious to see how it would affect performance, if at all.

What would boggle me, though, would be setting up a proper control system for it. Any thoughts from anyone on that?

This could be a great idea for a "group" project for some of us to work on.

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'74 Duster w/ HEI ignition, beat to snot suspension, A904, 8.25" 3.55 SG rear, still being tuned up and gets 17 MPG

Know how they always build a better idiot? That's me

Sorry about my confusion Dan. For as long as I can remember, I have been under the impression that Deisels were "detonation" engines; ones that ran off of an explosion as apposed to a controlled burn. The fact that they rattle so much pretty much reinforced that assumption. Do you have a suggested link to read more about this?

One of MPG Mikes economy tricks is to preheat the fuel using the coolant and a heat exchanger of some kind. You can't do this with a carb, because it will boil, but with EFI the fuel is under pressure and can be preheated, which allows for quicker atomization, and some vaporization, so you get some of the benefit of the old Pogue carburetor.

I ordered the book on how to build a Pogue carburetor back in the 70's and quickly gave up on it when I realized you would be drivinng around with a bomb under the hood. They claimed 200 MPH, and maybe it was possible, but I did not care to take the risk of the explosion that would ensue from a collision of some kind.

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I remember the ultrasonic article from back then; looked too hard for me to try then.

Later, I did see (J.C.Whitney?) an aftermarket ultrasonic device that lay flat under the carb and ran off of 12V. I suppose it could help distribute the acc. pump shot much better.

However, modern EFI systems probably can make much smaller drops than an ultrasonic system, so the later was not followed up.

Also, Smokey Y*? had a scheme of using very hot air + extreme turbo boost to make lots of power w/ good mileage in a 2cyl water cooled VW - the article was in either Popular Science or Popular Mechanics many years ago.

I'm not sure this would make a big improvement compared to port injection, although I can see the advantage on a throttle body. I think one of the biggest improvements might be in fuel distribution, as carbs and TBIs often have a bit of liquid fuel on the manifold floor - not good for combustion at all.

The thing is, with a port EFI injection, the fuel is atomized well enough to burn at least 97% of it or better, from what I've heard (and from what typical smog tests imply). Not much you can gain there. Lucas does build vapor injectors, and I think a few newer cars use them, but they don't seem to have a huge improvement. Chances are Pogue was more of a con man than anything else...

However, there are a few things to be said for vapor fuel, even in a port injection arrangement. For one thing, it doesn't stick to the intake manifold; I've heard some propane carbs can get away with not running an accelerator pump, for that reason.

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"Mad Scientist" Matt Cramer
'66 Dart - turbocharged 225
My blog - Mad Scientist Matt's Lair

Oof. If it was like the myriad other magical mystery widgets JC Witless has sold over the years, their aftermarket ultrasonic philharmonic hookedonphonic device did nothing at best.
I don't agree. If you watch a TBI system operating, you can see drops and streams of liquid fuel. Ultrasonics can create a perfect white mist. But this is comparing wet-manifold systems. Droplet size is much less relevant in a dry-manifold system (port fuel injection) and that's where the whole industry has gone on an OE basis.
Popular Science, April 1983. That's the adiabatic engine I mentioned.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

It's controlled-burn, but it is compression-initiated. You're correct that the diesel clatter is related to compression ignition.
Mmmm... http://en.wikipedia.org/wiki/Diesel_engine
You know exactly what I'm going to say to this idea, right? (I don't buy it, where's the data?).

[qutoe]with EFI the fuel is under pressure and can be preheated, which allows for quicker atomization[/quote]

I don't think there'd be any significant improvement in atomisation by preheating the fuel as described. Remember what happens when you spray any pressurised liquid through a small orifice (it gives up heat, i.e., cools way down -- this is why your A/C works). The effect is very strong and without crunching numbers, I would hazard a fairly reliable guess that this effect would utterly nullify any such preheating. What's more, it takes a given amount of energy to do a given amount of work, so even assuming this preheating notion works, the laws of physics dictate that the hotter fuel will be less dense, therefore less energy-dense, therefore requiring a greater volume of fuel to do a given amount of work, therefore no increase (and a possible decrease) in fuel economy.
You too, eh?
200mph and 200mpg are both fully possible with those underhood bombs: That's the approximate speed at which you would be blown to kingdom come, and if you work out and total-up the distance your various parts would be strewn by the explosion, and the amount of fuel that actually exploded, 200mpg is not out of the question.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Thanks Dan - my memory isn't what it was, and I had no memory of what the SY system was called and didn't immediately connect it with the previous descriptions. Please forgive my foggyness.

I've not looked into a running TBI; I'm surprised that the droplets are so large, because I had a discussion a while back with a Seimen's engineer and they were pushing for very small (10s of micron-ish?) laser-cut holes in their injector for better atomization. With such small holes, you need a lot of them.

Some of the new diesel injectors use powerful piezoelectric stacks rather than coils; I presume to provide much higher pressures. I seem to remember they run around 400V or so.

It has also been suggested that one can pump microwave power in and use that to better vaporize the fuel, especially for diesel engines, but I've no idea if anybody has tried it. It could perhaps greatly reduce the carbon particle emissions that are carcinogenic. However, smaller droplets from the above high pressure injectors may obviate the need for such complex systems.

They may even be some advantage to larger drops in direct port injection, as the evaporation may help cool the mixture, allowing greater density.

I also vaguely remember some scheme where the fuel was injected and burned as it was injected during the power stroke...

I find it interesting that the Phillips Stirling was also included in the emissions chart with exceptional results (forecasted at least). I've always been an admirer of the simplicity of the Stirling. While waiting for a perscription this evening, I found an interesting article in Frank Markus' column in the latest Motor Trend. It pointed at this youtube site - http://www.youtube.com/watch?v=h6vSxR6UKFM

In the article it stated that they used the flame from the testtube of saltwater to power a small stirling, which can be observed in the video. The method of realeasing the hydrogen from the testube seemed alot like the tranducer from your EFI thread. Isn't it interesting how things work back around on you?

diagram of the Phillips Stirling - http://www.alexdenouden.nl/08/stirling.htm

explanation of the Stirling cycle - http://auto.howstuffworks.com/stirling-engine1.htm

P.S. when I googled Frank Markus to see which magazine he wrote for (couldn't remember if it was MT or C&D) the first link that came up was a gay automotive website. I've always enjoyed his articles when I've treated myself to a non-mopar auto mag. I did not know that Frank was openly Gay.

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It is easier to REACT,
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Middy.