See through jet

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metiz
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See through jet

Post by metiz » Wed Nov 12, 2008 9:26 pm

See through engine. explains itself. This build is based on Mike's "Muffler shop special" engine. Completely made out of 1mm SS. boxed with intake and exhaust flush with the bottom of the cc. The tailpipe needs to be quite a bit longer but the steel didn't like me today so I'll fix that tomorrow or something.

I intend to jb weld the glass to the engine for sealing and use some more heat resistant stuff for filling and strength I'm going to use some steel wire or similar to keep it in place. Any suggestions on injectors or starting tips to get this thing going as soon as possible for the glass breaks?


Also, I can't take credit for this idea. mr microjet (ha) made this work before but on a much smaller scale http://www.youtube.com/watch?v=8Mn8Q-bfaxQ

pics below
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100_0326.jpg
100_0325.jpg
100_0324.jpg
100_0323.jpg
Last edited by metiz on Wed Nov 12, 2008 11:14 pm, edited 1 time in total.
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PyroJoe
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Re: See through jet

Post by PyroJoe » Wed Nov 12, 2008 10:49 pm

That was Mikes muffler shop special. That square CC may need to be 1/5 longer than the cylinder version, though it will probably run at that length. So what type of glass do you have there?

metiz
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Re: See through jet

Post by metiz » Wed Nov 12, 2008 11:15 pm

Oeps. fixed. It's normal, i think 4mm window glass. it will shatter soon enough so i hope i'll get one good run in before it does. also I did make choke cones on this one and on the muffler there are almost none to speak of
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metiz
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Re: See through jet

Post by metiz » Thu Nov 13, 2008 3:02 pm

finished. added the last tailpipe piece and a intake flare
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GRIM
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Re: See through jet

Post by GRIM » Thu Nov 13, 2008 3:46 pm

Metiz,
Looking good , have you considered putting some steel on the window first , so you can get a feel for the start up, fuelling etc,
then once all that tedious stuff is sorted , put your glass on ,

It might also be an idea to slowly pre heat your glass with a propane torch , to help avoid the thermal shock ,
just an idea

Good luck, and get some vid, get the lighting right , and be careful ,

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Re: See through jet

Post by PyroJoe » Thu Nov 13, 2008 4:15 pm

It would be a fun to fasten it to a piece of wood and run for a few seconds...making your own unique pulse jet brand. ha

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metiz
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Re: See through jet

Post by metiz » Thu Nov 13, 2008 4:24 pm

Hey GRIMM,

despite carefull planning and construction, the edges are not perfectly flush. if I put a piece of steel on it, I have to epoxy and whatnot the entitre thing together and I only have a small window for testing so I think I'll just go for broke. as for the heating part - can you give me some advice on how to do this without breaking the glass in the attempt and without getting to much sutt (or however you spell that) on the glass?

I was thinking on just sticking a Rossco down the intake and fire it up. suggestions on the width of the slit and how deep it should go in the intake?

Also, if all else fails, there's more glass where that came from :P
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Re: See through jet

Post by GRIM » Thu Nov 13, 2008 8:37 pm

Have you considered a flange or lip around the "window frame" see dwg , this would help greatly with sealing , or even better make a "u" shaped keeper so the glass is trapped ,

A strap accross the centre might also be worth considering , it would help control the thermal deformation,

The Glass should be heated very slowly , If you dont have a propane torch , put a rosscoe down the centre of a piece of pipe , about 1" to 1 1/2" dia 12" or so long , light the end , you should find a position where you can get a nice blue flame , this will not produce soot ,

another possible would be barbecue the whole deal , kind of spit roast :D

Good luck I hope this works , the video will be priceless ,
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window (Small) (2).JPG

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Re: See through jet

Post by metiz » Fri Nov 14, 2008 10:52 pm

ok the engine is all but done. can't make a picture now because all the adhesives are drying. I could realy use some advice on that injector though. At the moment I have a Rosscojector opened up a bit (only on 75% for some reason to about 0.5 mm. the flame looks nice and blue with a noticable gap between the injector tip and the actual flame. It flames out pretty soon, nowhere near full tap. Any suggestions on injector positions? I just want to get a couple of oppinions of you guys so I have the biggest chance of starting this thing up as fast as possible.
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metiz
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Re: See through jet

Post by metiz » Sat Nov 15, 2008 6:35 pm

Something came up. there goes my small window of oportunity. ill try next week.
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Re: See through jet

Post by Mark » Sun Nov 16, 2008 4:04 pm

This is a very interesting thread to me. Unfortunately, I can't think of any helpful hints other than what has been mentioned. I was looking at some expansion rates and thought it funny that oak and pyrex glass have about the same numbers. One time I had a thick store-bought quart jar that grapefruit slices came in. When I jam jarred it, it cracked in about 3 seconds, the fastest jar that ever cracked on me. It was kind of cold in the garage and that might have added to the failure, the hot/cold gradient. Thinner glass is less likely to crack, I had a chemist tell me that when I was buying erlemeyer flasks. The thicker flasks seemed more solid and aesthetically pleasing, but are more likely to fail when quickly heated. I guess the best route would be to gradually heat the glass evenly all over, sort of pre-warm it so at least the first part of the curve/rate of expansion will transition with low stress.
Note the large spread between plate glass and quartz. Iron and plate glass are fairly close, but who knows how the curve or rate of expansion matches. If you could get a template and grind your edges even, maybe you could get away with using clamps and gasket material instead of adhesives, or as mentioned flange out the edges. A clamped windowpane might afford a little bit of play/slide so that there would be less stress than the interface of a steel, adhesive, and glass union. And for trial and error, the ability to quickly change out the glass would be a blessing. A gasket material might soften the vibrations too, which if you get any backfiring or machine-gunning, the glass may give out less often.
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Jutte
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Re: See through jet

Post by Jutte » Mon Nov 17, 2008 7:32 am

You can try heating the glass and steel parts together by pouring
increasing hotter water onto the engine.When finally really hot
water is poured on you should be able to fire up the engine.
Should lessen the thermal shock a bit - enough to get some good pictures/vids hopefully
I saw a picture that Nasa had of a vortex combustion chamber
set up they had that is pretty much what you have Metiz.
Of course they had mega amounts of dollars to throw at it - but hey
don't we all wish we had access to that sort of funding...LOL.

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Shattering performance - see through tested

Post by metiz » Sat Nov 22, 2008 2:15 pm

Well that went a bit faster then I hoped for. Not much to say here, just watch the vid :P

Next up: safety glass
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Re: Shattering performance - see through tested

Post by Viv » Sat Nov 22, 2008 3:10 pm

metiz wrote:Well that went a bit faster then I hoped for. Not much to say here, just watch the vid :P

Next up: safety glass
Hey Metiz

I will give you top marks for that! you had at least one good cycle before the return wave built up enough compression for glass to give way, thicker or tougher glass yes but a good effort none the less.

If you can edit the raw video enough to pick out that first or second cycle it may show some thing more?

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metiz
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Re: See through jet

Post by metiz » Sat Nov 22, 2008 4:04 pm

I just got this send to me from James who in turn got it from Viv.(thanks man!) It's a super slomo of the 2 cycles.
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