Re: $50 Device Doubles Mileage: Isn't It Another #$%^& Scam?


Some possibly reputable sources have suggested using a little electricity from the alternator to generate a little H2 and O2 (2H2O + electricity => 2H2 + O2) will in fact improve the combustion of diesel or gasoline enough so that the higher efficiency of the fuel combustion more than pays for the energy taked from the engine by the higher load on the alternator belt.
But it ain't gonna be an 100% _overall_ increase in efficiency.
The first question in any efficiency improvement claim is "where was the inefficiency in the first place?"
The hard fact of life is that most of the fuel is _already_ being burned in a well tuned vehicle's cylinders.
GM claims they can improve fuel efficiency by 15% with better combustion but that engine won't be out for at least 6 years.
So the real improvement in any after market enhanced combustion approach to improving efficiency is less than 15%, probably much less.
The "mechanical engineer" on the videoclip was flat out lying about the 70 mpg.
Back in the 70s GM had a way of dealing with scammers and crackpots: They told them to bring their vehicle on down to their test track and allow the attendant to weigh the vegicle. After so many laps they'ld weigh the vehicle again.
The attendant didn't have to talk to many frauds because the frauds knew better than to allow anyone to weigh their vehicles and count laps.
There already is a $60 invention that will vastly improve miles/ gallon. It was invented over 150 years ago:
The bicycle.
Bret Cahill

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Dear Bret Cahill:
...

It is "just" a matter of having maximum pressure at mid stroke.
...

How true. Of course, they are a little more than $60 for an adult... and kind of hard to put "spinners" on. ;>)
David A. Smith
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Maybe $100 at Walmart but we weren't talking new stuff anyway. The fuel scam was aftermarket.
Bret Cahill
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The only way to make significant improvements in efficiency of ICE is to play with the thermo cycle itself, i. e., recuperated low pressure ratio.
Use different machinery to compress the air and expand the gas and use the exhaust to preheat the air after it is compressed but before it is combusted in or before the expander.
The engine is considerably larger for the power than high compression ratio but engine size is just not an issue in many applications, i. e., ships. The cost of _bunker_ is the issue on ships.
Even plug in series hybrids like the Volt with small 15kW engines might be able to devote 3X more space under the hood if the efficiency was over 50%.
Bret Cahill
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Dear Bret Cahill:

No, that is not the only way. One could look at "non-circular cranking", so that the enitre downward sweep of the piston was delivering energy to the transmission (rather than just increasing stress in the members).
How one would accomplish this in any sort of mechanism that would operate as trouble-free as a Piston-ConnectingRod-Crank arrangement, remains an exercise for the reader. Maybe that is where turbines come in.
David A. Smith
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The more waste heat can be recuperated, however, the more the diagram starts to approach isothermal.

Place an adiabatic engine cycle inside a T-S diagram of a Carnot or other isothermal cycle, Stirling or Ericsson II, and it's almost as sorry as a triangular cycle ~ 1/2 Carnot.
If the simple thermo cycle isn't a parallelogram, no amount of tweaking will make a dramatic difference.
There just isn't any way to get much more than 40% overall efficiency from ICE without using some waste heat recovery scheme, i. e., combined cycle or regeneration or recuperation.
That's how it was easy to know the guy in the video was lying about doubling efficiency.
The most efficient engine in the world, the 100 ton GE industrial gas turbine, is only 60% efficient.

Brayton is just another adiabatic engine cycle.
Wilson turbines is trying to make an ultra high efficient regenerated low compression ratio engine.
If they can keep the pressure drop in the regenerator -- his patent is for the regenerator -- low the engine could be 55% efficient as he claims.
A Prius could then get 70 mpg instead of 50.
I made a spread sheet to compare the mechanical energy required to accomplish the necessary heat transfer at different velocities. Some engineer claimed that if the flow rates are low enough [a big regenerator] then it is possible. He was correct.
I'ld like to see someone try recuperation or regeneration with a 2 stroke vessel diesel.
They would need 3X the displacement for the same power, a low pressure ratio compressor, reciprocating or turbo, some way to heat and ignite the 6-oil, and a huge recuperator that was easy to clean.
The [unrecuperated] version of the engine cycle might be more Otto than Diesel by injecting and burning the fuel as fast as possible at top dead center. Otto is more efficient than Diesel for a given compression ratio.
Low pressure ratio greatly reduces smog as well so they could put a tiger on it, talking the Port Authorities of Long Beach and LA to go after the vessel owners.
Bret Cahill
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Dear Bret Cahill:

Which is where the turbo comes in.

Well excuse me, but isn't 40% a significant improvement over ~13%? (And I may have themal efficiency in mind, rather than percentage of Carnot...)

Seems like 30% efficiency would be double the usualy 13-15% we get now, and well within your "40%".

The big piston engines on ships are / were very efficient, because they were slow.

It is sure easier to go after the two or three hundred biggest engines, rather than the million or so engines that put out far more and consume far more... but tend to carry more votes.
Tax gasoline to $10 per gallon, and spend the money on mass transit infrastructure.
Put a turbine in a Prius.
David A. Smith
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Jane's lists thousands of motor vessels but you are basically correct.
There are two kinds of economies of scale, individual copy size and volume size.
It's a whole lot easier to prototype a big engine that is more or less custom made anyway than trying to retool an entire high volume production line.

The P. As. of LA and Long Beach don't mess around. They don't want smoggy high compression combustion anywhere near the coast.

Either that or give everyone a revenue neutral rebate and let the market sort it out.
Right now petroleum is sucking all resources including labor from sustainability. Geo and solar thermal are suffering.

Series plug in hybrids like the Volt would be even better. The small "box" size would allow for more batteries.
You could lose a 15 kW gas turbine in a shoe box.
Bret Cahill
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Lloyds, not Jane's, lists all the motor vessels.
I've been in the desert too long.
Bret Cahill
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Dear Bret Cahill:

It's the 111 degfF temp.
David A. Smith
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

That's when I start to get creative, "low entropy" being the thermodynamic term for "opportunity."
Bret Cahill
"It is true that around each man a fatal circle is traced beyond which he may not pass. But within the wide verge of that circle, he is powerful and free. As it is with individuals so it is with nations."
-- DeTocqueville
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
N:dlzc D:aol T:com (dlzc) wrote:

Rotary engine. Ancient technology. Discover it.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Dear John:

Still indirect, with the pressurized face at an angle other than 90 deg to the crank for the full stroke.
But you knew that, and decided to pop in anyway.
David A. Smith
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Bret Cahill wrote:

A side issue, talking about situations where size doesn't matter: what about combined heat and power (CHP) micro-generation applications?
I know there are efforts to produce a domestic-sized central heating boiler that generates a few kW of electricity, and that there are some devices on the market. These are based on various technologies other than the tried and tested piston engine, I presume the main target is to minimise maintenance (although this parameter is conspicuous by its absence in the marketing literature). With the long duty, a conventional automotive engine would need stripping every few months which would defeat any cost benefits.
It occurs to me that one could build an system based on a regular car engine, using the established LPG conversion technology to burn natural gas, and revving very slow, maybe around 100rpm, using an oversized flywheel. Efficiency will be reduced due to conductive cooling during the power cycle, but it is not really an issue here as the primary output is heat, and mean electrical output required less than 10% of that.
Once you have electrical and rotating power available it is relatively cheap to add on heat pumping systems to maximise the efficiency of the heating side.
Just a thought.
Tim Jackson the www.tim-jackson.co.uk one
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Very interesting concept. All you want in CHP is complete combustion. High mechanical efficiency is desired but not really all that important if you are burning 2 oil anyway.
There certainly won't be any shortage of large used SUV engines that can be acquired at a low price.
They could be put to good use helping charge up your EV.
The Japanese are on ICE microCHP so it wouldn't be anything completely new.
Alternatively, instead of low rpm the SUV engines might be modified for low compression ratio recuperated.
The power would still be well above the 10 kW wiring of a typical house so some reduction in RPM would still be necessary.
Bret Cahill
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

It takes energy to compress. What's maximum in your theory? 15:1? 30:1? And ratio of oxidant to fuel? What fuel? Get real.

Hot air/fuel is inefficient. A cool mixture gives more power per volume.
Could it be y'all are heading down the same path the 500 mile-per-gallon carburetor nutz have gone?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Dear John:

Did I say it didn't? "What if" on the power stroke, the piston drove a ratchet and pawl mechanism, and the entire power stoke fired directly into rotating the crank? Instead of spending 45deg of travel just bending steel? It's only a "mechanical problem".

You start first. Rather than sniping.
David A. Smith
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
N:dlzc D:aol T:com (dlzc) wrote:

I can't envision what you mean. Sorry. I'd need a picture.
But as an aside, here is a link to a page I did (megawd) back in 1996 or so. http://www.digoliardi.net/strange.htm
Even with that picture I can't tell what's going on.
It's part of a book I got in England of strange motorcycle engines. I must find the book again. There were some very unconventional ideas.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Ah, I found the other strange engine page thanks to some kind soul who archived stuff way back when.
See this one: http://www.digoliardi.net/stranger
stranger than strange
I'll try to recover the bad images.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The pistons are driven (somehow) by the complex "torque tube" arrangement coming out to the driving gear. Concentric crankshfts.
Looks like it would generate all sorts of torque, and be really problematic.
Both are pretty cool, nevertheless. Thanks!
David A. Smith
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.