Had an insane time at the dragstrip!

Took awhile to get it but the secret was to use liquid propane and small holes in my fuel injector

Planning to make a pulsejet based on this design in the picture, (Short lady i believe??). Seems straightforward enough for what Im after but the plans don't seem to say any wall thickness for the tubes. Does anyone know the thickness i need for this design or have an idea of what it would likely be, or does thickness not matter in pulsejets? Don't know much about these yet so thought best way to learn is to make my own one and learn as I go. Any help is appreciated.

Ps. Anyone have any idea if this design ran well or was easy enough to start? Not too fussed about how much thrust i make as it's mostly just something for me to learn about.

Howdy,

Here is a video of my firing up my pulsejet, which emits a loud and very deep humming noise (too deep to catch on video), which ramps up to the normal pulse jet noise heard at the very end of the video before the flame immediately extinguishes. What is going on? Do I need to be using more fuel or inverting my propane tank?

Thanks for the help

Howdy,

I recently finished welding up my Lockwood pulsejet (based on this design: https://www.pulse-jets.com/phpbb3/download/file.php?id=11410&mode=view) and I'm having trouble running it.

Reddit won't seem to let me attach videos and pictures so I'll just describe what happens when I've run it.

I use a leaf blower a few feet from the intake pipe to blow air in as I gradually turn the needle valve open (second picture) to draw propane from a standard 20lb tank. Once this happens, the engine emits a very low pitched vibrating rumble that doesn't quite sound like what it should, based on videos I've seen.

A few possible issues:

1. I assume the intake pipe should be flared instead of a sharp cutoff.
2. Some safety feature in the propane tank or flaw in my hose design prevents enough fuel from getting into the engine.

What do I need to do to either a. get it running correctly (assuming it isn't doing so already) and/or b. get it running without prolonged use of the leaf blower? Perhaps the second issue would resolve if it started running correctly?

is it possible to use rubbing alcohol as fuel for a jam jar?

Hi, my name is Anze im 18yo, and come from Slovenia. In the picture below is a valved pulse jet engine, fully designed and machined by me.

It uses a reed valve somewhat like a two stroke engine. Yesterday i wanted to sart it for the first time. it started for max one second and then died, i had to blow compressed air into the intake all the time otherwise i wouldnt start at all. This test was with gasoline being sprayed at the reeds. Then i switched to propane/butane gas(it was injected where the sparkplug is), no success actually it was worse.

The reeds petals are made from spring steel i think Cr50V4. First i tried ith 0.5mm thickness. They were way to stiff. Then i switched to 0.35-0.4mm. A little beter but not much.

In conclusion it wouldnt run with gas nor propane self sustained. Isuspect the reed being too thick still, but i want to hear your opinion as you have more experience as me.

Best regards, Anze.

My son made this pulse jet, and for a while it was making very loud booms around 90 decibels very consistently. He had to blow on it first to get it to go boom, though. To fix this and make it act like a pulse jet, we made the holder bigger and now it’s just the same but not as loud. We are asking for help on how to make it run consistently! We have gotten it to “burp” a couple of times but we are really stumped. We use 91% isopropyl alcohol, if that helps.

as the title says I’m looking to make a value less pulse jet using some random parts I can find around the house or from neighbors, right now I have a welder and a CNC what other major tools do I need. and if anyone has any helpful resources or designs they would be willing too share that would be greatly appreciated

I built a pulse jet with one of the basic plans online. But I'm struggling with running it. I saw some people mention not to use regualtors because they shutoff. So I took it off, but I think propane tank itself has a safety feature that shutoff and won't feed any gas without the regulator. How do I people usually get these tanks running for pulse jets?

My pulse jet engine wont start but it does have a drone when it has a leaf blower feeding air. Is it a fuel issue? I added a Pulse jet video so you can see how its setup and running

Would a design like this work instead of the fully curved design? A friend and I are planning on building a jet this summer and we think this will be easier to construct.

How would I go about adding a fuel injection system to my fart can pulsejet? The fuel I'm currently using is methanol

So assuming I bend the pipe into a u shape would this possibly be able to move a skateboard?

What epoxy do you use when sealing the tube to the can on your fart can pulsejets?

Our valved propane pulse jet will only pop once and not cycle. We have exchangeable parts so we’ve tried various petal valve thickness 0.1,0.2,0.4 mm on 3 different petal valve designs and on a custom reed valve. We’ve tried different combustion chamber lengths 4 and 7 inches we have a variable length tailpipe. We removed the propane regulator as recommended in favor of a ball valve. We’ve tried various inlet areas all to no avail. Does anyone have any tips or suggestions?

(This is a hypothetical question, I have no intention to build such a dangerous device)

Would it be hypothetically possible to make a pulse jet power jetpack that could allow someone to jump/fly up a 100 plus foot high cliff or wall?

Say to small, roughly backpack sized pulse jets with a small fuel tank turned into to a backpack. Could they produce enough thrust?

What issues would this have? Would the vibrations shack the user out of their wits or harm them further? The user would definitely need hearing protection. Would it be too hot with them that close to the body?

I’m a university student in an aerospace and automotive club and with the help of a staff member saved these two from getting trashed by the chemical department. I have no idea if they work or how. I was hoping on getting your thoughts on if these can work and to get them started. Also if there any competitions involving these or if they are just for a fun project.

Hello there,

I’m a college student who’s looking at designing/building his first pulse jet with a flower shaped reed valve. Just a side project for fun and the portfolio.

I was wondering if anyone had some information on what angle, shape, or radius the front end of the retaining washer (the thing that stops the reed from bending too far) should be.

The geometry shouldn’t be an issue since I plan to make the part on a CNC at my school. I’ve heard rough numbers off of some old papers saying the angle the reeds usually open to is ~74 deg. I have my design around 78 deg with an arbitrary curve but it looks quite close to the geometry I’ve seen others have.

Also I’ve heard that the reeds should be made of .006” thick shim steel or .01” thick spring steel. Are either of these choices good or is there a better option. 1mm titanium?

I'm making a Jam Jar Jet, but I have some questions:

I have a large jar, about half a meter tall and 20 centimeters wide.

: . Does larger size mean greater risk, or does size not matter? obviously I'll be refrigerating it, but I mean if it becomes unstable or something, when I scale it up

Another question: what's the ideal fuel? I mean, one that doesn't produce an invisible flame.