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More in the saga of Thermo-Jam ( and other musings )

Posted: Wed Jun 15, 2011 7:14 am
by Ghrey
I suppose I should sort of make this a build thread of sorts, .... over time...

For now I will give the preliminary video of some of my recent activities ( some of you have already found the YouTube video ) and some stills of the star of the show.

The Video....
<iframe width="560" height="349" src="" frameborder="0" allowfullscreen></iframe>

If all that link and html stuff works great, otherwise goto youtube my user name is dszqujd Watch; Assorted tests.m4v

The last device is of some interest and is part of my (slowly) on going development of the " Thermo-Jam " I will add more detail later, this is just a starter.
Port end of CC oblique . . .
All ports View one
All ports view.
Original State
The Can ( before use as a cc )
More later.

Re: More in the saga of Thermo-Jam ( and other musings )

Posted: Wed Jun 15, 2011 4:46 pm
by Mike Everman
Cool. I didn't realize that was you!

Re: More in the saga of Thermo-Jam ( and other musings )

Posted: Thu Jun 16, 2011 2:53 am
by ganuganu
saw your video in youtube,i was really surprised to see that engine..great work..

Re: More in the saga of Thermo-Jam ( and other musings )

Posted: Thu Jul 07, 2011 9:00 am
by Ghrey
Brief update;

I got some work done this evening/early am on the carburetor for my next test, which will be made of pipe. Took lots of pics.

This next one will not, strictly speaking, be valveless.

More in a wile.


Re: More in the saga of Thermo-Jam ( and other musings )

Posted: Thu Jul 14, 2011 4:12 am
by Ghrey
I auto posted the final cut a wile ago and it defaulted to private, This took me a wile to sort out.

Here ( I hope ) it is...


Re: More in the saga of Thermo-Jam ( and other musings )

Posted: Fri Nov 25, 2011 6:16 am
by Ghrey
Just a brief note for a not so brief video...

Happy Thanksgiving.

Re: More in the saga of Thermo-Jam ( and other musings )

Posted: Fri Nov 25, 2011 1:56 pm
by tufty
Hah! Ben & Jerry's pulsejet! That's ace.

Re: More in the saga of Thermo-Jam ( and other musings )

Posted: Fri Nov 25, 2011 5:38 pm
by Mark
I liked the Ben and Jerry's jar. One time I had a paper mache' ostrich egg about that size explode when I went to light it, holding it in one hand the lighter in the other. It went off with such force that it stung my fingers. With the little can and snorkel that ramps up, I think a better fueling method might be the best bet. With my little Logan, if you put just a bit more fuel in it jam jar style, it chokes from the splashing of the fuel or dampens the feedback. In this video it starts with some hesitation, but often you can't detect the slightest ramp up, it seems to just instantly turn on full grease which is what I like best about it, faster than your senses with a sharper, piercing sound. In the video it's a flat lackluster start.
On your can boats it might help to use shorter lengths for that diameter or perhaps change/articulate the fueling. I like that Monster can you have, I fiddle with the one I have from time to time. It's nice that it has it's own lid.
Logan without fuel system

Re: More in the saga of Thermo-Jam ( and other musings )

Posted: Fri Nov 25, 2011 11:12 pm
by Mike Everman
Thanks for the chuckles. Brant. We're going to have to get together one of these days. Your jars that kick over are quite unique. Got to point noobies to these vids, just to show how persistent one should be with these.

Re: More in the saga of Thermo-Jam ( and other musings )

Posted: Sat Nov 26, 2011 8:29 am
by Ghrey
Well I got a nice long reply written then I fumble fingered it and poof....

Mike; It would be fun to get together some time, time and fuel permitting. If you would like a real portrait of persistence I will post a shot of my scrap pile, If I can stand far enough back to get it all in frame... :)

Mark : I try to watch my volume vs port size to minimize surprises, but BANG! happens.

I am working on an aspirator valve, which may facilitate greater volumes of sound. << see attached bits of mechanical madness >>

Re: More in the saga of Thermo-Jam ( and other musings )

Posted: Sun Nov 27, 2011 11:17 am
by Ghrey
This last little bit before there is a pause, More of the little glue can that can.

Excerpts from a lengthy session, a Best of if you will.

Methanol is the fuel.

I have some bigger stuff in the works, but most of my time is devoted to my children, ( 4 and 6 years old ) so it is likely to be a wile.

Re: More in the saga of Thermo-Jam ( and other musings )

Posted: Sun Nov 27, 2011 5:12 pm
by Mark
That's the ticket. It certainly gets gets going steady there. Can you tell what the snorkel is doing, if it's throwing out much air or not? I noticed on my piglet snorkelers that you can really hear the slosh on some false starts. If they are too full of fuel, they flameout after starting. Another thing I noticed is that they spit droplets of methanol out the snorkel, I once focused the camera right on the exhaust and you could see them coming off the interior edge of the snorkel for a few seconds before the neck got too hot and vaporized them. But of course your snorkeler is different in some ways because of the other two ports, proportion, and size. Some of the drops must get sucked back down/mixed with fresh air on the inflow phase I imagine.
I have a little metal syringe jam jar that revs up pretty fast, something that starts to approach what your open snorkeler sounds like when the air is very dry. I like how snorkels increase the jam jar effect and add a bit more sound though.
If you have seen my pint capacitor electrode, the round brass sphere is off a lamp I bought for use in jam jarring, back when I was toying with spherical jam jars - gazing balls, plastic lemons, ostrich eggs, smudge pots - whatever I could find. Anyway I attached a ridiculously long 3/8 inch piece of plumbing pipe about 18 inches long in one side that I threaded and the other a tiny short nipple of 1/4 inch at the other. The sphere with "snorkels/snorkel and snorkelette" would really rev up to a sharp whine/same sudden whirring sound from the get-go like your model but it only lasted a few seconds with the spritzing of fuel I gave it. I never got it to run steady though. Sometimes I left off the little 1/4 nipple and it did about the same. It kind of looked like a sceptor or wand if you can imagine, maybe one might consider it a mutated linear pulsejet in some way.

Again, good work and happy jam jar-ported snorkeling. It's nice to see someone experimenting as opposed to armchairing. Oddly it's a lot more work experimenting, trying as many variables as you think fruitful or having the stamina for. But it's often more revealing/rewarding too.
PS I guess you could argue that it's more work thinking, for like many things there are often no absolutes but lots of generalities or certain "scenario" absolutes. ha

Re: More in the saga of Thermo-Jam ( and other musings )

Posted: Sun Nov 27, 2011 8:01 pm
by multispool
Hi Ghrey,

Do you test at random? Just wondered why you always use what seems like an over-small diameter tailpipe
Logic would say that this will behave like a breather tube rather than a resonating tail section, is that deliberate?

Anyway thanks! I do find this thread interesting/entertaining...

Re: More in the saga of Thermo-Jam ( and other musings )

Posted: Mon Nov 28, 2011 7:27 am
by Ghrey
Multispool; in this case: It comes from my old jam jar formula.... ( follows )

If you have an approximately 2x3 ratio combustion chamber where the 2 is the diameter. then the maximum total port area is .2 x the actual diameter. Somewhat longer vessels still work well with the .2 rule as well. Spray paint cans for instance...

The tiny can is dividing it's total area by 3 which makes for a long thin pipe. To answer the logic question; Not a resonator. By design.

This is not scientific in any way but it seems to work for the questions I am currently asking...

Can they support a larger diameter tail pipe? Yes; See previous video of the spray foam can that goes to full pulse jet, But to run on a puddle, is limiting in this respect, at least so far, but I have some tests on my to do list with much more open designs, and real fuel systems...

Smaller not well. See the all pipe example in my previous video the tail pipe is deliberately a bit slim for the actual cc diameter, but it was an intake port study ; unsteady running can be revealing, if a bit hard to breathe around ( CO... ). That cc will be getting a bigger tail pipe when time permits. Thats the next stage in the intake port tests....

And yes some times I do just try random stuff, if it works it all gets measured and recorded. If not ...
The first little metal can was a case of TLAR and when I measured it sure enough real close to 2x3 @ .2

For better or worse thats the why...

As for gas flow out the long tube; yes it produces quite a breeze at peak, sometimes a steam plume puffs out when they are idling down. Methanol produces water. Water encourages rust...

edited to correct omission

Re: More in the saga of Thermo-Jam ( and other musings )

Posted: Mon Nov 28, 2011 3:00 pm
by Mark
Methanol also produces carbon dioxide. I came across this article where it was pointed out that you need CO2 as well for rusting. I found that a pinch of boric acid to make green fire with methanol will eat plumbing pipe like you wouldn't believe; threads and all will really degrade fast if you don't rinse off your equipment after experimenting. Probably a lot of impurities in combination with water will/would do as a "catalyst" of sorts. Probably even formaldehyde plays a part. Carbon dioxide in water forms carbonic acid, I wonder if that too is deleterious to jam jarring, being absorbed to some possibly significant degree in the slowly diluting pool of methanol in the bottom of a jar?

"Dr. G. T. Moody has shown that if very special pre-cautions are taken to exclude all traces of carbon dioxide, then iron may be left in contact with pure oxygen and water for many weeks without undergoing any change. In one of the experiments thirty times as much oxygen as is required to convert the whole of the iron into oxide was passed during the course of a few weeks, but there was absolutely no rust. But if the air were not freed from carbon dioxide rusting commenced at once, and in seventy-two hours the whole of the metal was corroded. There would seem to be no basis, therefore, for the assumtion that iron can be caused to rust by pure water and pure oxygen only."
(Scroll to bottom of page for the article)
Read more: ... z1exn5J6QN

CH30H + 1.502 -> CO2 + 2H20

With one of my long, tall chrome-plated ear syringes that ran for over 5 minutes in a coffee can water bath, it always had some liquid remaining after a run, and when I went to light the ounce or so that remained by pouring it out on the concrete it barely burned, it had become so watery. I had put an aluminum pie pan skirt around the syringe as well to keep the steam from the bath from getting sucked into the combustion chamber. I also had a fan set so it pulled any steam away from entering the intake of the syringe.

Related tidbit - Water is one thing that might be a good reason for introducing methanol into a jam jar as needed instead of relying on a pool of it in the bottom of a jar. Also if the combustion is too erratic or violent, the splash can introduce instability. My piglet snorkelers that have run for over 4 minutes or so glowing red hot will also have some watery alcohol remaining after a run. After they stop you can relight a plume of vapor that comes out of the snorkel and it will burn for a minute or so with over a foot of flame.

See also: Alcohol proof, Flash point, and Fire point
Liquor that contains 40% ABV (80 US proof) will catch fire if heated to about 79 °F (26 °C) and if an ignition source is applied to it. (This is called its flash point.[9] The flash point of pure alcohol is 62.88 °F (17.16 °C), less than average room temperature.[10])

The flash points of alcohol concentrations from 10% ABV to 96% ABV are shown below:[11]

10% — 120 °F (49 °C) — wine
20% — 97 °F (36 °C) — fortified wine
30% — 84 °F (29 °C)
40% — 79 °F (26 °C) — typical whisky
50% — 75 °F (24 °C) — strong whisky
60% — 72 °F (22 °C)
70% — 70 °F (21 °C) — absinthe
80% — 68 °F (20 °C)
90% — 63 °F (17 °C) — neutral grain spirit
96% — 63 °F (17 °C)
Beverages that have a low concentration of alcohol will burn if sufficiently heated and an ignition source (such as an electric spark or a match) is applied to them. For example, the flash point of ordinary wine containing 12.5% alcohol is about 125 °F (52 °C).[9][12]