Search found 1519 matches

by metiz
Fri Dec 07, 2018 10:55 am
Forum: Valveless pulsejet forum
Topic: Plumbing Pulse jet stalling
Replies: 2
Views: 58

Re: Plumbing Pulse jet stalling

Are you using a regulator on your propane bottle? As a rule of thumb: if you think you have too much gas, you don't have nearly enough.
What type of fuel injector are you using and how far down the intake is it?
Is your engine build from known plans (i.e., the pipewood/ ugly stick?)
by metiz
Tue Nov 20, 2018 11:33 pm
Forum: Valveless pulsejet forum
Topic: Lockwood Hiller pulse jet rules of thumb?
Replies: 3
Views: 120

Re: Lockwood Hiller pulse jet rules of thumb?

Hi! It might be a good idea to use Pyro's recipe for beginners for your first engine (it's for valveless engines). That lockwood engine is pretty crappy. For your first attempt, try making a linear engine. They are the most easy to do and easy to start. When you get bored of it, you can have it cut ...
by metiz
Fri Jun 22, 2018 9:57 pm
Forum: Valveless pulsejet forum
Topic: Please put your "I am new and need help" question here.
Replies: 374
Views: 1744832

Re: Please put your "I am new and need help" question here.

hermanpj wrote:
Fri Jun 22, 2018 9:46 pm
Has anyone died from home made pulse jet detonation? Just curious. 😀
I can guarantee no one has, since a pulse-jet deflagrates and not detonates :D
by metiz
Fri Jun 22, 2018 9:05 pm
Forum: Valveless pulsejet forum
Topic: Please put your "I am new and need help" question here.
Replies: 374
Views: 1744832

Re: Please put your "I am new and need help" question here.

Hi, welcome to the forum! I've been reading your questions and I have some feedback. Fair disclaimer: I have never worked with an ugly stick. In your first post you describe you get a pop or two but mostly yellow flames from the exhaust. To me that sounds like your ignition isn't up to scratch. init...
by metiz
Wed Aug 30, 2017 2:13 pm
Forum: Valveless pulsejet forum
Topic: Annular M20
Replies: 5
Views: 1321

Re: Annular M20

Thanks, Mark.
by metiz
Tue Aug 29, 2017 6:25 pm
Forum: Valveless pulsejet forum
Topic: Annular M20
Replies: 5
Views: 1321

Annular M20

I build an annular version of the M20 about a year ago. I could not get the injectors out far enough to get it to run. A couple of weeks back I fixed the issue and today I tried again. Although it runs, it's a huge pain in the ass to get going. Thrust is rather disappointing too: 11.4 pounds (origin...
by metiz
Thu Aug 17, 2017 11:55 am
Forum: Valveless pulsejet forum
Topic: Mike's Build Log
Replies: 379
Views: 106266

Re: Mike's Build Log

Hi Mike, Just a thought but the fuel you are using is ethanol? - very hydroscopic- Dave, a mate of mine, who is well into his chemistry, can process/refine it to remove almost all the water - I can ask him what it is he does to do this ( I recall he added something to the fuel and it solidifies at ...
by metiz
Mon Jul 31, 2017 10:51 pm
Forum: Off topic forum
Topic: youtube
Replies: 1454
Views: 166604

Re: youtube

I was realy excited to read that article, until I saw the 100 grand price. Not quite mainstream. 100 grand will buy you a lot of nice machining tools
by metiz
Tue Jun 13, 2017 8:06 pm
Forum: Off topic forum
Topic: youtube
Replies: 1454
Views: 166604

Re: youtube

Lol it's a scaled version of the M500, tailpipe reinforcements and all
by metiz
Wed Jan 18, 2017 5:11 pm
Forum: Valveless pulsejet forum
Topic: Thermojet not producing thrust
Replies: 1
Views: 767

Re: Thermojet not producing thrust

it doesn't look like you flared the intakes. This will limit throttle range and thus thrust. Flare them and try again. It'll run a lot harder
by metiz
Fri Oct 14, 2016 10:58 pm
Forum: Valved pulsejet forum
Topic: Pulse Jet Compression
Replies: 6
Views: 1808

Re: Pulse Jet Compression

Easily. No moving parts to waste energy on
by metiz
Thu Sep 22, 2016 10:14 pm
Forum: Valveless pulsejet forum
Topic: Do you see anything wrong with this pulse jet?
Replies: 8
Views: 1618

Re: Do you see anything wrong with this pulse jet?

I'm not sure about our injector suggestion - I have never done an injector like this. I don't think you'll be able to start automatically like this. just try with a hand hold Rosscojector to see if it starts easier. Once running, switching to liquid fuel should be doable.
by metiz
Wed Sep 21, 2016 3:55 pm
Forum: Valveless pulsejet forum
Topic: Do you see anything wrong with this pulse jet?
Replies: 8
Views: 1618

Re: Do you see anything wrong with this pulse jet?

Ah now I see. the small version of the picture made me believe that was a sparkplug. I think that is the crux of the problem though: the motor doesn't like the injector at that point. You want a tube pointing down the intake, depending on type, 0-50% of the length. The fuel is now delivered at the w...
by metiz
Tue Sep 20, 2016 10:40 pm
Forum: Valveless pulsejet forum
Topic: Do you see anything wrong with this pulse jet?
Replies: 8
Views: 1618

Re: Do you see anything wrong with this pulse jet?

Open up the spark gap a bit to get the gas to properly ignite. What kind of injector are you using, and is the propane bottle full and unrestricted?
by metiz
Fri Aug 19, 2016 9:43 am
Forum: Valved pulsejet forum
Topic: Pulse Jet Compression
Replies: 6
Views: 1808

Re: Pulse Jet Compression

I'm still here! :P