Anything you need or want to sell goes here.
Moderator: Mike Everman
1 post • Page 1 of 1
- Posts: 1859
- Joined: Sat Oct 04, 2003 1:17 am
- Antipspambot question: 0
- Location: United States
Beck Technologies 4Lb Thermojet Style Valveless Pulsejet on high throttle running off of propane.
$170.00 USD + Shipping
Due to the ever increasing price of stainless, the price may increase in the future, although I try to keep things as reasonable as possible.
This thread is a copy of my ebay auction listings, you may see these engines on ebay, better known as feebay, but we do not have them listed 100% of the time, but you can still purchase directly through us using Paypal.
We can also do custom modifications of any of these, such as different materials, injection orifices, pressure taps, and heat exchange coils etc etc.
This thread is for a Thermojet Style Valveless Pulsejet Engine, with spark plug, fuel injector, and a copy of the Beck Technologies Pulsejet CD with TP-180 Plans included free. The engine is all 304 stainless steel and is entirely TIG welded and leak free. It is made from 20 gauge stainless so it can handle long static test runs at full power without worrying about harming the engine.
Valveless pulsejets are an excellent way to get into hobby jet propulsion without having to spend $2000-$3000 or more on a turbine system. They have no moving parts, which means there is nothing to wear out or break mid flight. You can run it today and pack it up and 40 years later it will still run exactly the same. As long as you don’t completely abuse the engine or try using it as a baseball bat the engine will probably last longer than you will.
There are a number of misconceptions about pulsejets, some people think that they cannot operate statically, and that you cannot throttle them, this is not the case. They can run perfect standing totally still, or flying through the air at very high speeds, and they can go from minimum throttle to max faster than you can blink. With a decent fuel valve you can throttle the engine down to well under 10%. This engine is also able to be self started with no compressed air required, just turn on the ignition and the fuel and it starts up.
Other Pulsejets seen on Ebay
You may see other engines that look similar to this one ebay that are spot welded, spot welds leak since they are basically tiny welded points with large gaps between weld points. Spot welds should not be used for anything that needs to hold compression. This should be common sense, but spot welding is extremely cheap and easy to do, and I guess some people just don’t care about the quality of their products.
If the engine leaks, it is going to lose performance, if it can run at all. Also spot welds should not be used in parts that reach high temperature, metal expands and contracts as it is heated, and when there are only a number of points where it is welded these points concentrate stress and can eventually break. I know several people who actually threw away the spot welded engines after hours of frustration trying to start them. If you are not convinced, do some research online and I am sure you will find that my engines are the best valveless engines at any price.
The fuel injector is also included with this engine, and the engine also has a spark plug as an added way to start the engine. Why buy a cheap spot welded engine when you can get a rock solid TIG welded leak free engine with spark plug, fuel injector, and a copy of my Pulsejet CD for almost the same price?
The engine is approximately 22" long and has a max diameter of 3". The engine weighs about 1.4 pounds, and puts out a tremendous 4 Lbs of thrust on propane. Because the engine is entirely TIG welded and leak free you can also use a RC fuel pump and run the engine on just about any liquid fuel you can pump into it, from gasoline, to kerosene, and even straight methanol or the popular 80-20 mix.
The engines are brand new, never run. Because valveless pulsejets have no moving parts, their dimensions and construction determine everything about how they run. This is why good construction is so important. I use all the same techniques, equipment, and welding jigs to ensure each engine will run perfectly. I use welding flux to make sure all the welds are smooth on the inside and use welding jigs on critical areas to make sure the most important joints are totally seamless on the inside.
If you have questions or need help getting your engine running I am more than happy to help.
The injectors are set up for running on propane; several individuals have run liquid fuels through them without a problem, though they are optimized for propane. Propane is a great fuel, its relatively cheap and readily available, and in a self pressurized tank, so you don’t have to worry about spilling liquid fuels or cleaning up.
With propane you can start the engine without any forced air. The engine can be ignited with either an open flame to the intake, or a spark ignition source. With self starting all you have to do is turn on the propane fuel and have an ignition source, the force of the propane blowing into the engine will pull in air to mix with the fuel, and once it ignites the engine will start running and keep going.
Once the engine is running you don’t need to give it any forced air or provide a spark or open flame to keep it going, it will continue running all on its own as long as it has fuel.
For more information about this engine you can visit:
The picture above is of the 4LB Thermojet with a thrust augmenter mounted. Thrust augmenters are specially shaped ducts that you position behind the engine, the shape causes additional air to be sucked into the exhaust stream, where it mixes with super heated exhaust gas. The exhaust transfers heat to the fresh air causing it to expand and produce extra thrust with no additional moving parts and no extra fuel consumption.
A thrust augmenter duct is fairly easy to make, and would make a great subject for a science project, as there is a lot of research going on pertaining to augmenting pulse detonation engine thrust, and even NASA is using small pulsejets like these to test theories and new ideas.
Length: Approx 21"
Max Diameter: 3" / 7.6 cm
Tail Diameter: 1.25" / 3.2 cm
Approx Weight / Mass: 1.4 LBS / 635 grams
Thrust: 4 LBS / 1.8 Kg
Thrust Specific Fuel Consumption: 2.0 lbs fuel per lb thrust per hour with propane (less when augmented)
Once again this engine package includes:
4 Lb Thrust Thermojet Style Valveless Pulsejet Engine
Stainless dual intake fuel injector line optimized for propane
Pulsejet CD - ( tons of pictures, video, tutorial videos, over 40 pages of builders guides, and plans to built the TP-180 valveless pulsejet - All of it is 100% original content created by me)
Extras you can purchase for this engine:
Display and mounting stand $15
Light weight aluminum thrust augmenter $40
Boxed model T push button ignition system with safety key $125
Shipping in the US will be by USPS Priority Mail.
International shipping will be by USPS Global Express Mail which comes with tracking and insurance.
For international orders customs can sometimes be a delay, while the majority of items go through quickly and without incident, if you do not get your item in a timely manner do not wait weeks or months to to say anything!
Pulsejets, even small ones are absolutely not toys, they are for mature and responsible hobbyists. They get orange hot, and produce so much radiant heat that they can burn things close to them. They are also EXTREMELY loud. Pulsejets can be a fun and safe hobby if you follow a few simple safety rules like wearing hearing, and eye protection, and keeping the engine away from any flammable materials.
If you can not get a response from the email address on my site, your message may have been blocked by a spam filter, try a different email subject line, or try messaging me directly through this thread or private message.