How to build your own Jet Engine

Step 10: Have fun making lots of noise and shaking the ground while impressing friends and neighbors with your new toy!

This is the fun part! Starting your new engine for the first time. The parts you will need are...
1) The engine
2) Ear defenders (ear muffs)
3) Lots of fuel (diesel, kerosine, or jet-a)
4) A leaf blower
5) a washcloth

This is where things get interesting. Firstly you set up the jet in a place where you can actually start it without making anybody mad with the loud noise. Then you fuel it up with your choice of fuel. I like to use jet-a because it just works well and has the right "smell" of a jet engine. Switch on your oil system and set the oil pressure to a minimum of 30 psi. Put on your ear defenders and spool up the turbine by blowing air through the engine with the leaf blower. Yes, you can use electric or air starting on these engines, but it is not the norm, and it is much easier to just use the leaf blower. Turn on the ignition circuit and slowly apply the fuel by closing the bypass needle valve on the fuel system until you hear a "pop" when the combustor lights. Keep increasing the fuel and you will start to hear the roar of your new jet engine. Gradually pull the leaf blower away and see if the engine speeds up on its own. If it does not, reapply the leaf blower and give it more fuel until it does. Lastly enjoy the sound of your new engine and remember to use the washcloth to clean up in case you poo your pants! There is so much power in these engines that it will startle you to the point of losing bodily control.

Videos of our running engines are available as flash movies below. We hope you enjoy them! You will probably need to size your browser down when viewing them so they are not pixelated.

That is about it. Our websites cover all of the build processes and hopefully will get you started on the journey of making your very own jet engine. Be sure to send us pictures if you make your own.

Combustor kits can be purchased by contacting Russ at Bad Brothers Racing. Different kits and configurations are available to help you in creating your jet engine. Fully assembled engines are also available to qualified buyers who sign a release of liability. The plans in this documentation and kit designs are Copyright 2006 Bad Brothers Racing, and may not be reproduced in any way, nor may they be sold.

Please remember that our websites are funded by donations and clicks on advertisements. If you feel generous, please help out with a monetary donation. If you are cheap, give us a few "clicks for the cause" to help the projects keep coming! See you soon, and we hope that you enjoy the sites!

This information was provided by Bad Brothers Racing and Gary's Jet Journal. Please visit our sites to see what is new as we update often with new and exciting projects.
http://www.badbros.net
http://www.garysjetjournal.com

Comments

[Nander21a]

Has Anybody gotten enough thurst out of one of these to get some lift for an aircraft?

[jj.inc]

You could easily get enough for an aircraft if the engine is not on it, the only semi-practical use for one of these is a direct drive for a land vehicle, otherwise it is too heavy and fuel hungry.

[jj.inc]

Does anyone know how to attach a direct drive, so you can gear it down and turn some wheels, this doesn't run like an engine on a jet plane, it is more like a modern tank that uses a turbine to spin a pump to spin a motor ext. Except this lacks the connection shaft and I am not sure how to do it.

[Raphet123]

I am afraid this would not run on said diesel, kerosine, or jet-a, but i found with LNG it seems to run much more effective and efficient.

As for building it with aluminum, i found that this was a much simpler way of construction than the said methods above, due to the ease of which you can machine it.

[Tuwdburgaler]

yea, aluminum is a VERY bad idea, because of the gas it puts off when exposed to this kind of heat, its toxic and causes alzheimers, on top of that your bound to end up with a failing engine in general, and for machining your generally wrong, because special equipment is required to weld aluminum, and you can weld steel, iron, etc with basically any welder if you know what your doing and have the voltage skill and equipment

[Captain Kirk]

Ive seen a lot of these home made Jet's now. Whilst they seem to make a shed load of noise and produce impressive blue flames with an afterburner. They are still very low on thrust output. I belive to resolve this problem a seccond compressor is needed to run in serries with the first. Obviousley the first would need to be of a much greater diameter. such as a Diesel Locamotive Turbo compressor then pushing into a Garret T4 Compressor. Finaly before the Combustion chamber a large size (high Pressure) Intercooler could also help. The real task for a home Builder is how the bloody heck to drive both shafts with only one Turbine. But by Pre- compressing the air, then feeding it into a seccond compressor, then cooling the very hot gases with an Intercooler. You will have a far greater concentration of Oxygen and at a much cooler temerature as it first enters the combustion chamber. The result is a very efficient and powerfull combustion process. Last of all even a single stage turbine system could benefit from the use of an Intercooler. You just have to make sure you build one that can handle the very high pressures.

[danyelbergsma]

I slolved the thrust problem differently, I created pipe with holes drilled diagonally, this I then connected to the exhaust hole. It sort of works as a turbo on your exhaust, it increases your thrust incredibly high. I now hit speeds to about 150 mph.

[Electrix]

This is a great idea, I am considering using it on my Jet Engine. Could u please explain with more detail.

[Coffee bean]

u should try it

[crezzyman]

Or, instead of doing all that work and finding a very high pressure intercooler, you could just inject some straight nitrous oxide into the system, either directly into the inducer on the turbo or after the air has been compressed. It would give cooler air temps, and more oxygen as well. It would be useful for short runs at least, but really, who uses a DIY jet engine for anything other than short runs?

[Tuwdburgaler]

watch what you say dude, you have no idea how crazy us nerds get with our homeade jet engines

[Electrix]

good idea, but the combustion chamber would have to be able to withstand the extra pressure

[lordevilpoptart]

gr8 instructions guys this is just what i was looking for we got a project going here to basicly build a hover craft in which i will need 4-6 engines depending on how we do it but i will need no where neer 1500hp per engine though i do have a question we plan on designing to use hydrogen and karosen mix what affect do you think this would have? more power? would it be bad on the engine? i plan on running everything normal but cutting down the karosen and mixing hydrogen with oxygn prior to combustion do you think i should have a second oxygen intake to have more oxygen? i appricate any sugestions

[da_huss]

That's the same way real jet engines run.. air enters a larger compression area first, turning a turbine shaft while forcing the air into a tube with a quickly shrinking diameter.. the air leaves the tiny end of the tube at a much higher rate into a smaller sharper finned compressor, further compressing the air while turning a secondary turbine shaft. The shafts run between the compressors, intake prop, and a 3rd turbine behind the combustion chamber. The extremely dense and fast moving air coming from the secondary compressor enters the combustion chamber and mixes with fuel, which ignites and is forced out the rear through the 3rd turbine. Both compressors share an outer turbine shaft "shell" to help each other run, while the 3rd turbine runs the second "internal" shaft which turns the intake prop.

[Electrix]

Thanks man, u helped heaps

[da_huss]

Correction.. there are 2 turbines behind the combustion chamber. The first is a low compression turbine which turns the compressors.. the second is a high compression turbine which turns the intake prop.

[Captain Kirk]

Whoop's, I meant the Promary Compressor would need to be larger than the Seccondary. Obviousley the Primary will feed into the Seccondary. In this way it is possible to increase the compression ration. However massive amounts of heat are generated during the commpressing process. Have you ever felt the end of a Bicycle pump after using it, well its the same thing. That is why an Intercooler is needed to reduce that heat. It will also have the additional benefit of reducing the pressure at the intake to the combustion chamber, whilst increasing Oxygen density.

[Captain Kirk]

Primary Compressor !!

[Captain Kirk]

and Compression Ratio ... Sorry my keyboard is having an off day LOL.

[Gdz2010]

It might even be possible (and very ambitious) to make your own axi-centrifugal compressor for higher compression ratios. You would need to be good with 3D CAD, CNC machining, and casting, not to mention familiar with fluid dynamics and turbo machinery design. It would be a really fun project...one of these days....

[Captain Kirk]

Its not necesary to Make a Compressor !!. At the very most the ability to be able to make a custom shaft. There is nothing wrong with Turbo Compressors as has been shown may times with working versions of these Jets. But to build a twin compressor version, you would need to be able to join two standard Compressors together using a single shaft. Both Compressors must be rotating in the same direction. This is where it gets complicated. A custom manifold would be needed at the intake of one of the compressors to allow the custom shaft to pass through it, whilst still allowing air flow. At a potential 200,000 rpm the alingment of this shaft is uber critical !!. The hardest part would be to create these two components, neither of which requier emense skills in fluid dynamics. Just simply very good machinary and operator skill.

[Gdz2010]

I know that turbochargers work, I'm just saying it would be a fun project to attempt and it would have the benefit of being smaller and therefore more suited to a propulsion application.

Somebody made a one stage compressor from scratch and posted a vid on youtube. http://youtube.com/watch?v=oO37TNF1TjU

I was thinking of something along those lines; having the stator vanes from the first stage feed into the inlet of a coaxial second stage.
I only suggest it because I like making as much as I can from scratch before buying anything premade. Nevertheless, any homebuilt turbojet deserves respect.

[Captain Kirk]

The Maifold on the front of the seccondary compressor would have to come off the intake and then turn through 90 deg. A normal Hi pressure Turbo hose could then be connected to the output of the Primary Compressor. The shaft would need to pass through the wall of the manifold, with a flange and bearing assembly mounted on the side of the manifold. The primary compressor wheel could then be attached complete with standard turbo compressor housing. As I said before the hardest part would be to make the manifold. Getting the parts to produce a good compressor would be easy. Its making sure that everything lines up correctly. Also the Shaft would need to be manufactured with the uttmost precision. The rest could be achived with some quality alluminum welding and accurace machining. The resulting Twin Compressor Jet, would be very compact and produce an incredible high thrust output.

[savagefukeronsteroids]

killer wats the power to weight ratio i might try one see wat i cook on the exhaust

[hiigaran]

suppose you make some of these jets and then add them onto an aircraft of 12m wing span and 6m fuselage length. would 2 or 3 be sufficient? and before anyone says that it wont produce enough thrust, consider this: the jet would have an intercooler, a secondary tank around the combustion chamber (main fuel tank delivers fuel here. purpose is to cool combustion chamber, and pre-heat the fuel for better combustion), and fuel injectors at the start of the exhaust nozzle for extra burning.

[nasda]

I think ure right and I think it would be sufficient.oh? if ure building an aircraft can u help me

[hiigaran]

sure - what do you need to know?

[killerjackalope]

I was very interested in doing this a while ago but everything else got in my way and I never did get to an answer of possibility with the research I did. Now I really am dying to build a turbo jet for a project that I have been concoting and wanted something more than rocket power (it's not reusable) Have you any figures for the amount of thrust provided by your jet. I can easily aquire a reconditioned turbo of something big cheaply (thinking front loader or loading shovels as I know there are just the parts i need lying around people's workshops from now broken machines. also how much did the whole assembly weigh before and after you put on the afterburners.

[ghandi]

very impressive project, have you built a pulse jet yet? PS:I think if you add an afterburner you will increase overall efficiency, though it will require more fuel.

[russwmoore]

Hi, I have built a pulse jet. They are fun, but don't compare in power to a turbine. Still, their ease of construction makes them a great project to build in a few hours. As for the afterburner, I actually have dual burners on the bike right now. See our website www.badbros.net for more info on how things turned out!

[AlbinoBlackSheep]

kool idea, but won't the superbike burn your butt off? it looks like the engine's exhaust port is right where one's butt is traditionally placed.

[russwmoore]

The picture of the bike was just a mock up. For pictures of the real bike, go to my website at http://www.badbros.net and follow along for the entire build process.

[Ogrecycle]

Me thinks after the Ogrecycle A jet cart is in my future thanks and good job!Ogrecycle

[russwmoore]

Glad you like the project. I think you will enjoy building one up. I enjoyed reading about the OgreCycle too! Nice contraption of parts that shouldn't go together, but did quite nicely! Keep up the good work!