DIY Pulse Jet Design, Build and Run

I had a go at building a valveless pulse jet engine - something I always wanted to do. It runs on small gas canisters at the moment, but I hope to build a liquid fuel system for it sometime.

[DaveWoods-kuem]

I'm glad you've revered the extinguisher

[drck]

So just some helpful advice for your version 2.0. Since this is a Lockwood-Hiller Design, your exhaust tube should roughly be 1.5-2 times the diameter of the intake tube. Also, the exhaust tube and your combustion chamber should have roughly the same volume. You want to keep around an (8.7:1) ratio of the diameter to the length of the exhaust pipe. If too long then the exhaust gases will "burn out" and cool down too much -- making it impossible for them to ignite the fresh air/fuel mixture. Try and keep the exhaust and intake ends almost the same length with the exhaust slightly longer to avoid sucking in the exhaust. Also from a safety standpoint take the fuel line off of the exhaust tube as when the engine starts and gets to temp it will make the propane self-ignite within the tube. I commend you on actually getting up and building something. Trial and error is a very good professor for hobbyists and professionals alike. Always be learning and be able to accept positive criticism in order to improve your projects and yourself. Good luck in your future endeavors young man. I look forward to the next version.

[getherdoneproduction]

I love that you made it work with a stick welder. You give your fellow budget pulse jet enthusiast hope

[randallmarsh]

That is just awesome.. put some cooling coils around the hot spots and use the intake vacumn to draw the heated air in..

[kempy]

Excellent 👍 Definite sub from me.
On to part
All the best,
Paul
PS. Not too bad a welding job considering it was stick welds on thin walled tubing 👍

[Bruh_L_Moment]

So sick! Im currently in the process of trying to cast some aluminum to make one. Not going to be easy but hopefully it works!

[glumpy]

Been thinking about waste oil in one of these but I haven't even attempted to build one. Big credit to you for getting it right so easily. You could use LPG from BBQ gas bottles to get the jet hot which will phase change the oil from a Liquid to a vapor and it may tun then. Fuel delivery will be the crucial factor. I'd suggest something like a Roller type Fuel pump ( Bosch 044 Type) and them something like a carb jet or a needle valve to control the fuel flow.

I would think warming the jet up hot and running at Minimum throttle and then adding the oil to run it hard and turn off the gas. I don't think pre heating the oil as everyone suggests with these things would help. Just have it going to a red hot part of the chamber and it will vaporize. Be very interesting to see how this goes as I can think of a bunch of things happening but what matter and what determines if the engine will run or not is a different thing.

You sure would have an interesting engine though that could be used for heat and maybe power and if you could run it on waste oil, you could run the thing long as you liked.... or could stand it.

[pierrelaboom]

Greetings, from New Hampshire! Great job on the pulse jet first build! I've built several ranging in size, most run from a 20 gallon propane tank, and wow they just chew through the fuel!, I've switched over to gasoline with a fuel injection pump, Saab, but most pumps over 70 psi will work. A nozzle from a furnace to get it going easily, then to a copper.030 mig welder tip, spraying against 1/2 steel disc suspended mid compression chamber an inch from the tip, still eats the fuel, but it's cheaper! I Isubcribed today!

[davidblake]

Cool jet. Well done! Have you considered Iron Bru for a combustion source? 🙂

[DaveWoods-kuem]

Hey man that's very interesting I'd help you if you want to continue researching I'm in Cheshire I suppose your either newscastle or Rochdale I think you'll do well I'd bring me tent

[diegowilson]

Could you please do a video on building your valve amplifier ? It resembles a Trainwreck amp, which is the style I'm most interested in, so I'm curious what you did with yours. You play guitar, or at least enjoy trying to, right !? We look like we could be brothers across the pond, so I suspect we're off the same age group.

[Michiel_baan]

Nice build!
And a good explain
Do you got Some building plans for me?

[pierrelaboom]

Very cool indeed! What is that, an icelandic Finnish on some of your words? Hardly noticable! Good video!

[brandonlaragirl]

Any idea of how much thrust it produced running off of propane or acetylene?

[DaveWoods-kuem]

All you got to doo now is connect it to old moped and zoom to Middlewich come see me

[elebeu]

Props for butt welding tubing with a buzz box.

[Jkauppa]

try rocket nozzle widening valveless continuous burn "pulse" jet, more like afterburner than pulse jet tho

[funkiwikid]

I love it, make the next one bigger ! Gotta lose that stupid high viz though, they're loose, flammable and usually just a neon sign advertising I've got no idea what I'm doing so when it all goes wrong, please don't run me over as well. And most importantly, H and S will have pity on me when I'm laying in hospital after being shrunk wrapped in dayglo orange synthetic high viz material. Trade the fire extinguisher in on a bigger gas bottle.

[DaveWoods-kuem]

Put it in your truck down right dangerous

[markiobook]

Sorry, saw you're very soaked feline and so many single entendres came to mind. British humour. Of course a Scot with a cheeky wee peek can assemble it in jiffy. Scottish- genetic engineers. "I'll just add a wee bit here"- goes like a Buzzbomb.
Is there a limit on the fuels you can use? I'd imagine it wouldn't take to heavier oils?