www.pulse-jets.com

I saw the plans for the pulse jet made with the pipe and I had to do it. The engine is almost exactly the same as the one that was mentioned in the thread. Here is a video and some pictures of me trying to start it unsuccessfully. My fuel stinger is 1/8" dia soft copper. Does anyone have any advice ...

pezman wrote: Yeah, I seem to remember that equation cropping up a couple of diplomas back... Apply it and you will see that 0.5 * 2700F * 2.5^2 gives a figure of 8437.5 joules.

Whoa! 2700F? Where did you find a 2700F capacitor?!?! :?:

Those large caps on ebay are used for car stereo systems where the car's battery can't provide enoguh current during a large bass surge etc... They're MUCH larger than a battery that would work better for powering an ignition system. I use a television flyback transformer and a two MOSFET circuit as...

So then I guess that the cap that Mark showed would start it several thousand times ... Did you even read the links before replying? Do you understand the equation 1/2CV^2 ? It calculates the number of joules a capacitor can store. Put 2v in, and then put 12v in. You'll see the difference immediate...

Capacitors are good for quick, high current pulses. Batteries have a much better energy density for things like starting a pulse jet. A cap would have to be HUGE, like 100,000µF at 12v or something, and that would give you just enough time to start it, but it would be larger than the battery and wo...

Not really, unless you're building a little tiny robot or need a memory backup in your clock or something.

Here's a schematic I drew of a sparker. The values aren't really critical except for voltage. The resistor values have some slop to them, but I haven't tested anything, 10K might not be enough to prevent explosions of components :).

You can do this more sophisticatedly (sp?) using a ignition coil, a camera flash and a SIDAC which is a device that triggers when a certain voltage is reached across it. With a small capacitor ~1µF and a 240v SIDAC along with an ignition coil and camera flash, you can get a reliable ignition system...

The sizes are as follow: Intake - 0.260" Id. X 2" Long ( occluded by a 1/8" Od. fuel probe Tailpipe _ 5/16" Id. X 8" l. plus a 3/8" Id. extension X 4" 12" Comb. - 1 3/16" Id. X 2 3/4" l. Hmm did I? I thought about that... but not enough. I made that out of parts in my junk pile, so I'm not too worr...

I got it "finished" if that's what you can call it... I can't weld at all, so my welds are crap, lots of pinholes etc. I did get the engine to fire, and "run" i.e. it resonates, but it will NOT self sustain. I'd been using a 1/8" fuel line but when I had the gas valve open all the way, it still woul...

I LOVE the simplicity of this engine. I welded up a CC today, about 1.5" shorter than an aluminum soda can, about the same diameter. (I like to make first, measure later :) ) Hopefully it will work! I'll be using a .625 id tailpipe at X length.

It's definently .007" I weakened the connection of the petals to the main ring of the valve, and I can now get the engine to run (sort of) while blowign air into it with the leafblower. My sparkplug was only "friction fit" and it came loose when the engine heated up. It leaks air around it, I wonder...

So did I buy the wrong reedvalve material then?

That run in the video killed the reedvalves, so I ordered some 1019 tempered blued .07" spring steel... however, it's too thick and the engine can't open the valves without me blowing air into the engine, so it only (barely) runs with forced air. I made the mistake of reading bruce simpson's site fo...

Nope, doesn't work, the flame just ignites at the end up of the pipe, it won't travel back the tailpipe into the CC. I guess I need acetelyne!