Small valveless

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multispool
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Small valveless

Post by multispool » Sun Jun 11, 2006 11:44 pm

Hi Guys,
I'd like to build a very small yet reasonably reliable valveless!
Any suggestions as to size and type to go for? The main criteria is that it must be small, thrust is irrelevant...

NickC
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re: Small valveless

Post by NickC » Mon Jun 12, 2006 12:15 am

how small :|

its usually helpful to include something like maximum dimensions. check out these free plans http://beck-technologies.com/freeplans.html, its pretty small

multispool
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re: Small valveless

Post by multispool » Mon Jun 12, 2006 10:44 am

I was thinking about half that size!

Eric, Does your calculator work for engines this small?

NickC
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re: Small valveless

Post by NickC » Mon Jun 12, 2006 11:03 am

i believe you can scale that FWE. just divide all the measurements by 2 :D

multispool
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re: Small valveless

Post by multispool » Mon Jun 12, 2006 11:31 am

Hi Nick,
That would fall in line with what I had in mind. I have some 16mm id s/s tube which would be only 0.125mm out from spec at 1/2 scale. Can I really directly scale down all measurements? That route wouldn't work with gas turbines, but I'm only a PJ newbe!

My aim is first to get something very small to work, then see how small I can go while sticking with convntional fuel like propane...

El-Kablooey
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re: Small valveless

Post by El-Kablooey » Mon Jun 12, 2006 3:44 pm


Eric
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re: Small valveless

Post by Eric » Mon Jun 12, 2006 4:16 pm

scale the diameters by 1/2, and scale the combustion chamber length by 1/2, scale the length of the tailpipe and intake by around 60%.

I have plans for a micro chinese that I am going to upload to my site soon. The sites not behaving, I am probably going to recode the whole thing and wipe everything and upload the new.

Eric
Image

Talking like a pirate does not qualify as experience, this should be common sense, as pirates have little real life experience in anything other than smelling bad, and contracting venereal diseases

multispool
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re: Small valveless

Post by multispool » Mon Jun 12, 2006 4:20 pm

Thanks for the help guys,
That should be enough to get me started!

multispool
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re: Small valveless

Post by multispool » Sun Jun 18, 2006 6:16 pm

I decided to go for Erics FWE at 50%. Not run yet, only just finished it!

Tricky to make, all in 0.8mm s/s. Didn't have suitable tube for the inlet so machined it from solid bar...
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Johansson
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re: Small valveless

Post by Johansson » Sun Jun 18, 2006 6:25 pm

I hope that it runs as good as it looks! Great work!

//Anders

multispool
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re: Small valveless

Post by multispool » Sun Jun 18, 2006 6:48 pm

Thanks Anders, What size gas nozzle do you think I'll need?

NickC
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re: Small valveless

Post by NickC » Sun Jun 18, 2006 6:49 pm

interesting choice of sparkplug placement? any reason why you chose it over placing the sparkplug on the dome?

Johansson
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re: Small valveless

Post by Johansson » Sun Jun 18, 2006 6:57 pm

Hmm, I ain´t the right person to answer but I guess that a brake line would be enough. Since the intake area is really small a large diameter injector will block the intake more than necessary...

//Anders

Bruno Ogorelec
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Re: re: Small valveless

Post by Bruno Ogorelec » Sun Jun 18, 2006 8:55 pm

multispool wrote:Didn't have suitable tube for the inlet so machined it from solid bar...
Billet intake... that's a new one, for sure. Custom car builders, take note.

multispool
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re: Small valveless

Post by multispool » Sun Jun 18, 2006 9:29 pm

NickC, I scratched my head over that for a couple of days, even made two front end plates. one formed out of sheet and the other machined from solid with a thicker center to take a 1/4 x 32 thread for a home-made plug but had second thoughts about the complication. The larger 10mm plug would have meant that a large percentage of the front plate would be missing it's concave shape which I was afraid might upset operation. Where its now, the plug is slightly recessed so the tiny chamber shape has been preserved. Well that was the theory anyway...

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