DIY Jet Engines....Anyone?

Status
Not open for further replies.
Joined
May 1, 2012
Messages
2,919
Location
Indiana
Not sure where to put this....

I went to a recent inventor/science/maker fair recently.

One thing that caught my attention was the amateur jet engine guys. They had both pulse-jet engines and turbine jet engines made from turbo chargers. Boy, they looked cool. Louder than heck. Very cool though.

Definately got my attention. Might be something that I try building for fun. Most of the engines were on stands for demonstration purposes only. But they did have an engine mounted to a bicycle, to a small pocket bike, and a go-kart.

If I fabricated one of these engines, I'd want it functional....put some wheels under it.

Anyone on here ever tinker with these designs?
 
Last edited:
My uncle built a ramjet in the early 1960s and fastened it to the roof of an early 1950s Plymouth.

The story varies according to who tells it. My uncle claimed it worked and the car went [fill in the blanks insane extraordinary] mph.

My Dad says the car's flathead six didn't have enough power to get the ramjet up to ignition speed. Flames just shot out of the back of it, but it never ignited.
 
You can make a pulse jet from an aerosol can, feeler gauge and fence pipe.

I'm impressed with anything more complex as a DIY.

A ramjet needs to be going fast to work. I would be surprised if they worked at race car speeds even.
 
A group of engineers in Ann Arbor some thirty years ago worked on turbine engines to bring them to more ordinary commercial applications. My old boss was involved in that program. He mentioned that they powered a prototype riding mower with a turbine engine.
 
Originally Posted By: Cardenio327
My uncle built a ramjet in the early 1960s and fastened it to the roof of an early 1950s Plymouth.

The story varies according to who tells it. My uncle claimed it worked and the car went [fill in the blanks insane extraordinary] mph.

My Dad says the car's flathead six didn't have enough power to get the ramjet up to ignition speed. Flames just shot out of the back of it, but it never ignited.


Unless that old flathead six could get the car up to 700+ mph, the ramjet would never produce thrust. A ramjet has to be going at sonic velocities to get a shock wave to form in its inlet, causing compression of the incoming air. Otherwise, he just had a fancy blowtorch.
 
Speaking of jet-powered vehicles.......
grin2.gif
 
Originally Posted By: Kestas
A group of engineers in Ann Arbor some thirty years ago worked on turbine engines to bring them to more ordinary commercial applications. My old boss was involved in that program. He mentioned that they powered a prototype riding mower with a turbine engine.


30 years ago? Bump that up. There was a bunch of work in the 1950s and 1960s, but the failure was a settled issue by 1970s. The no-load fuel consumption is just too high for applications where partial-throttle efficiency matters more than peak power to weight ration.

A lawn mower comes closer to the profile than a car, but still a has a broad range of power needs.
 
Which makes me wonder - a hybrid with a turbine would be a great idea. You could put a large battery in it, and have the turbine turn on and off as needed. Sort of like the Volt but with a turbine.
 
Originally Posted By: itguy08
Which makes me wonder - a hybrid with a turbine would be a great idea. You could put a large battery in it, and have the turbine turn on and off as needed. Sort of like the Volt but with a turbine.


GM did that with EV1 but obviously never released it to the public.

Audi's E-tron had a wankel in the back ala Volt style.
 
I've built turbo based jet engines and non turbo based gas turbines. A few liquid fueled rocket engines and so on.

It's quite easy if you know the basics of turbo machinery. It's impossible if you don't understand how and why they work. For every success story, there are many failures you don't hear about. Remember that compressor and turbine sizing is very important. Along with proper combustion chamber design.


As for practical use, forget it. I one turbojet I built made 300 pounds of thrust and consumed about a 55 gallon drum of fuel per hour.
 
Status
Not open for further replies.
Back
Top