some questions about jam jars

[grant richardson]

What is a jam jar engine? I saw something on the net about one. I have a ragu glass bottle with a meatl lid. I drilled a hole in it . 5/16 hole in the top. I covered the bottom of the jar with some glow fuel (Methanol) and shook the jar until i felt the pressure in the jar. then i lit the hole and i got a loud swhoosh followed by a pulse or two and thats it. I drilled the hole bigger with the same results.

How do you build a jam jar engine?

[Bruno Ogorelec]

Grant,

This is the list of instructions put together by Ben Brockert:

1. Get a pint sized mason jar, or a glass jar that used to contain jelly or jam (thus the name 'jam jar').

2. Drill a 0.5 inch (13mm) hole in the center of the lid.

3. Add just enough methanol to cover the bottom. Adding too much will kill the combustion by swishing around too much and creating a fuel/air ratio that is too high.

4. Cover the hole with your finger, and swish the methanol around, When you remove your finger, there should be a slight 'phish' because of the vapor pressure of the methanol. If it doesn't phish, your lid isn't sealing properly.

5. Put on your safety glasses.

6. Light the jar at the hole with a long butane charcoal lighter or a long fireplace match. (If it doesn't light, shake the jar to increase fuel/air ratio inside the jam jar.) The jar will putter happily.

7. Put out the jar within five or ten seconds, or it will get too hot and crack. It can be extinguished by covering the hole. Don't use your finger to cover the hole.

8. Congratulations, you just made a pulse jet engine!

[Mike Everman]

Hey, Grant.
I'm in the same spot, and experimenting now. I just made my first SWOP! (not an acronym, a sound) though the chamber is too small. I'll let you know if I get a sustaining configuration, and what all you will need.
These fittings are way over-kill on strength, which for a demo I like.

[Viv]

Hey, Grant.
I'm in the same spot, and experimenting now. I just made my first SWOP! (not an acronym, a sound) though the chamber is too small. I'll let you know if I get a sustaining configuration, and what all you will need.
These fittings are way over-kill on strength, which for a demo I like.

Hey Mike! the one on the right looks ok, take the thin pipe off it and reduce the hole down to 13mm.

Make sure you seel the threads with some PTFT tape or something.

Standing it in some water will help to keep it going, you can use a pipet to drop fuel in the top whil it is running.

I am still trying to get Nick to post a video of his steel jam jar running, it realy does rock!

Viv

[Hank]

Hello- The Jam Jar Engine you describe will sustain a flame front for one or two poots. I came up with one that will burn until the fuel runs out or your MOM starts yelling at you.
Here is a verbal description of the basic Whittle Jam Jar Engine, as posted in Jetzilla Magazine. (Where's Larry?)

Take one 6 fluid ounce glass jar with a metal lid. Wash out the vegemite dregs.

Drill a 1" hole in the center of the lid. If you do not have a 1" hole saw you can make a hole by "walking" a nail around the perimeter of the hole you wish to create with a hammer.

Between the hole you have drilled in the center and the perimeter (outer edge) of the lid drill 6 equally spaced holes 1/4" or 5/16" in diameter.

Cut a 6" length of 1" diameter metal tubing. This is your exaust duct. You can secure it in the 1" hole you drilled in the lid with a few twists of wire or some Marmon Clamps (hose clamps).

Put a small amount of the combustable material you wish to use as fuel in the Jar.

Screw on the lid.

Take the Engine outside near where the cat is sleeping. Set the engine on a non-flammable surface.

Ignite the fuel. Be careful, the initial burn will exit both the exaust duct and the smaller intake holes you drilled.

Once going this burner will sustain convective combustion . Be careful, it's hot.
It will crack, eventually.

Watch the light show as the flames eddy and swirl. Enjoy.

Hank

[Mark]

What is a jam jar engine? I saw something on the net about one. I have a ragu glass bottle with a meatl lid. I drilled a hole in it . 5/16 hole in the top. I covered the bottom of the jar with some glow fuel (Methanol) and shook the jar until i felt the pressure in the jar. then i lit the hole and i got a loud swhoosh followed by a pulse or two and thats it. I drilled the hole bigger with the same results.

How do you build a jam jar engine?

Try this. Get a Mason Jar where you can be sure you are getting an air tight seal. Put only enough methanol in the bottom to barely cover the bottom. Too much and it will all fly up in the jar killing resonance. Then drill a half inch hole or slightly less in the lid. Shake with finger over the hole. Dry off the hole on the top of any residual alcohol. Light it carefully so as to not interfer with the first whooose. I don't think you can fail doing this. It the whoose is lackluster, you need to air it out again thoroughly and fresh methanol is a must. If it is some that has been left out or in a bottle with loose fitting lid, it will take the water out of the air and become less peppy.
You will really like this experiment, it is very fascinating.
Mark

[Mark]

What is a jam jar engine? I saw something on the net about one. I have a ragu glass bottle with a meatl lid. I drilled a hole in it . 5/16 hole in the top. I covered the bottom of the jar with some glow fuel (Methanol) and shook the jar until i felt the pressure in the jar. then i lit the hole and i got a loud swhoosh followed by a pulse or two and thats it. I drilled the hole bigger with the same results.

How do you build a jam jar engine?

It dawns on my your glow fuel may be glow fuel. That won't cut the mustard. It contains castor oil and nitromethane. Both dilute the methanol and nitro smokes which further compounds the problem. Get some HEET from Walmart or some dry gas from an auto parts store like an Autozone Store. Read the bottle, if it says contains methanol, that's what you want. And remember, just enough to cover the bottom of the jar!
Mark

[nmasters]

And add a pinch of boric acid (brazing flux) to the fuel for color so you can see the flames

[Mike Everman]

Get some HEET from Walmart or some dry gas from an auto parts store like an Autozone Store. Read the bottle, if it says contains methanol, that's what you want. And remember, just enough to cover the bottom of the jar!

I was just playing with that stuff today! Quite Peppy, as Mark would say.

Mark, I swear is our Pulse Jet Poet. Please keep it coming and forgive me for the following:
I keep expecting Mark to say something like: "My brother and I got a 5 Kg sack of plutonium one time on E-bay, and used to sit around it and feel the heat on our, well, all through us really, and for some hair raising times (that was just a saying at that time) we would put the material in this heavy cast iron shoe scraper in the shape of Felix the Cat I found at a garage sale one day that I stumbled on on my way to get random plumbing fittings. Anyway, you put the plutonium in the bowl, carefully lining the depressions with a 1mm layer, or it won't work, mix up some depleted uranium, which you can find at Home Depot under the brand name "Atomic Model Boat Ballast" with 98% pure peroxide. Dump it in there while one of you holds a copper coil of tubing with mercury in it, and if you can't find mercury, you can use that gel stuff in those really cushy bike seats. Anyway make sure that you electrically short the coil and before too long, it'll make this wwwwhhooooowweeeeK-k-k-k-k-kspzzz sound, and then wait just about 6 seconds and the magnetic field produced will literally de-spin all the electrons in your body. I usually feel quite edgy waiting for it to happen. Good times, you should try this."

[Bruno Ogorelec]

Mike, this was spot-on. I loved your spoof! It describes our Mark exactly. I keep being flabbergasted by the tricks he will pull out of his sleeves, but sometimes even more so by the way his mind wanders through organic-philosophical free association. He keeps providing philosophical spice to this forum. Also, he appears able to whip up a valveless pulsejet at a drop of a hat.

For those who haven't seen his work, here's just a couple of glimpses:

[Viv]

Mike, this was spot-on. I loved your spoof! It describes our Mark exactly. I keep being flabbergasted by the tricks he will pull out of his sleeves, but sometimes even more so by the way his mind wanders through organic-philosophical free association. He keeps providing philosophical spice to this forum. Also, he appears able to whip up a valveless pulsejet at a drop of a hat.

For those who haven't seen his work, here's just a couple of glimpses:

Spoof?? you mean that wasn't Mark! merd that took me right in:-)

Viv

[Mark]

Such flattery is nice, but I'd say Chris, Gary, and Bruce, and some ambitious British welders are further along in the valveless realm. I can offer you extreme weight and undentability though. And I don't have any top secret ideas that I know of.
I find now that I want to make some kind of art form, something pleasing to the eye. I'm toying with Pyrex now. I was reading that if you can keep the gradient of heat in the glass below 150 degrees C, that 50% of the glass objects won't shatter in a test. For thicker glass the temperature goes down. Thicker glass cracks before a thinner glass.
With pure quartz glass thin sheets can be heated red hot and dunked into cold water without cracking. Quartz it is said is something like 7 times better than Pyrex in the low expansion game. Look at those new flash bake ovens with quartz glass bulbs or just a quartz glass room heater where the elements glow red hot inside the SiO2 in just a few seconds.
Don't quote me on the pyrex temperature facts, I am recollecting something I read quickly while surfing.
I remember those Prince Rupert's drops, I saw them first in a Nat. Geographic article on glass. Tear drops of molten glass that plop into cold water. Some survive and the outside of the glass cools before the inside and you can whack the drops with a hammer and they won't break, but if you clip the wispy tail they shatter with a forceful pop.

http://faraday.physics.uiowa.edu/mech/1R20.70.htm
http://www.cmog.org/page.cfm?page=281

Mark

[Mark]

PS I left out some other good valveless experimenter's names, but it's nice that with all of us here, imput keeps flowing in -- in all sorts of ways, shapes, and forms, netted from all over the world.
At times I feel I can't think of single new thing to try, that pulsejets or similar creations are just a boring dead-end street. Then at other times, I feel like the things to try are endless and deeply interesting.
Maybe the mind/body, aside from wanting to propagate/procreate itself in the usual way, is drawn to pulsating combustion, to recreate/associate itself with these resonant objects too, recognizing a vague commonality in the vocal life-like musical resonance the molecules exhibit. Of course too, it could be, we just like noise.
Enough purple berries for me.
Mark

[Mike Everman]

Oh, my Budda Mark, that was classic! LOL

[Mike Kirney]

I've been trying to get my online homage to Mark back up onto the net but the place where I store all the content keeps going down. I'll think of something in the next few days and those who have never seen it before can have a look and a listen. Mark is truly a diverse character. He works at the library, he plays with machine tools, and he owns a handgun. Hmmm. He was a real Haiku superstar back when that was fashionable here on the forums. I raise my latte mug to you, Mark 'Thixis', and I hope that you find many more purple berries behind the Spanish Moss.