www.pulse-jets.com

Valved and valveless engines have different geometries, so you can't just convert one into the other

here it is again

Good stuff. Try adding some NOx to the fuel mixture for a nice boost. If you want to build an augmenter, check here

That's the stuff! Congratulations. Did you feel your bones rattle? Looking at your video, I think you can run it a lot harder still.

Try freehanding the injector to find the sweet spot. If you still can't get it to start, see if you can borrow a compressor somewhere.

Sorry...still not running :? You need more gas. Here's a video of an engine built with Pyrojoe's specs from a couple of years back. It's a bit bigger but the same type. I start it using only a Rosscojector. I've uploaded the whole thing, including all the failed attempts. Maybe you can get some poin...

...you've built 4 engines already without starting even one? Bold move

If you're using a rosscojector, the injector needs to be positioned farther out instead of in. Pretty close to the flare actually. If the flame blows out, you have your injector positioned incorrectly. To find the sweet-spot, hold the injector in your hand and light it. Hold it in the intake in a po...

That's better. It's not running though. You need a lot more gas, like, x3. I don't know if you are wearing any hearing protection but if you're not: for the love of tinnitus, do. When it does lock in, it's going to be the loudest thing you've ever heard.

Is there no sound or is it a problem on my end?

The Rosscojector is that pinched tube, yes. I've linked to it in the other thread. It looks like your copper pipe is kinked. Try bending it in a bigger loop to prevent that. Also use 2 hose clamps to secure the injector and make sure the injector is pointing straight into the intake. See my masterfu...

What kind of injector did you use? A Rosscojector should be able to start an engine of this size without the need for compressed air, if you find the sweet spot. I'm looking forward to your video. If it's possible, also post a picture of your injector, injector setup and fuel delivery system.

Sounds good. Just make sure you don't mechanically constrain the front AND the back of the engine. When it gets hot it will expand a bit and if it can't move, something's gonna buckle. If your engine is red-hot and soft, guess what'll happen.

That's more like it! Did you sleeve the intake with a 2nd piece?

Hello ScrapQueen, welcome to the forum. For a first build, those welds don't look half bad. My first thermojet looked horrendous. To business: I doubt your engine is going to run. Your exhaust pipe looks to be too fat and too short. Your intake is way too long. Having the intake in the wrong directi...