# Pot-Bellied Backyard Stirling Engine



## IronHorse

Well I woke up one day late last year yearning to build a whacky engine. You know the kind; Large, made from reclaimed parts, lots of pipes and spinning things and no bling. I started with the Moriya engine plans. I like this design because you can scale it up or down and it always works. Basically it is a 2X scale engine with water cooling. I modeled the engine in Pro/Engineer first to make sure everything worked and to work out all the dimensions. 








I found this Made in Taiwan miniature pot-bellied stove at a local Antique/Junk store. I am sure it was meant to be purely ornamental, but with working dampers, grate, ash tray and provision for a chimney, it was perfect! I fabricated a chimney up out of some pipe and sheet metal and mounted the engine to the top. The engine will run at 400Rpm with a nice fire below.








The cold cylinder was made from 2 pieces of aluminum tubing. I machined the inner tube so it would fit inside the outer tube, and then hogged out the inside of the outer tube. I then sandwiched them between two thick plates. 







The power cylinder is mounted in what I call a flying Flangemethod and the piston inside is from graphite.






The pump is basically the same as the one used on the Ericson Hot Air Engine, with a few minor modifications.











The brass water reservoir is a part I found in the garbage at work, I think it is for a de-humidifier. It had a float attached to one end,which I cut out and soldered the copper pipe to. I also added a small Cookingthermometer so I can monitor the water temperature.







Although Hot Air Engines are inherently safe, I made apressure relief valve just in case. I figured that since this is water cooled,and there is only a gasket to seal it, If ever there was a leak of water into the hot cylinder, I would have a sealed Boiler! This would be very dangerous,so I made the valve to be on the safe side.






It ran the first time real good. It will run at 300RPM witha propane torch on full, but it will run forever  at 100RPM on the smallest flame (¼) I can get on the torch. There may be some more power available to run a small generator,but first I am going to do a propane conversion so I can run it inside this winter.




















And finally a Video. It was -4Deg C this morning when I made this.





IronHorse


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## nemoc

Nice job IronHorse.  Thm:  The Moriya was a great choice to upscale.  Mine has been running great for a few years now. Thanks for the pics and video.

Craig


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## Shopguy

That is one unique neat engine.  
Ernie Johnson


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## canadianhorsepower

th_wavBravo awsome project:bow:


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## Philjoe5

Nice work + you've already got the stove to sit around and watch it run

Congrats

Phil


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## ieezitin

Iron. Congratulations on a win, a very nice engine indeed which has a wonderful sound.

Anthony.


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## hvirtane

This looks great. 

Can you give a link, where the original drawings are, which you used and 
also give the dimensions you used? 

-hv


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## polygon

Beautiful work.


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## Stieglitz

Hopefully One Day.....Great Engineering Congratulations.


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## StarRocker

Awesome job!  I really enjoyed this!  The video is very cool also!!


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## Fred Slifer

Well done.
My original scale Moria has been running well at shows for several years.
Perhaps a fan at ( or in place of ) the flywheel would spread the potbelly heat around your shop.
Fastfreddy


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## franscubitt

Have you powered anything from the flywheel yet?
It should be able to generate power but it is beautiful on it own, Well done
Chers Frans Cubitt


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## jgd

this is possible you can post the plans, thanks.


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## Yoff

Very nice, congratulations.


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## jeroenvw

Very nice!! Congrats with the win 
Cheers from The Netherlands


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## Bob Bailey

A truly fine job! Thanks


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## etard

That is truly awesome!  I would be interested to know how much electricity this engine could generate.


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## tomo

Iinnovative work, it's a pleasure to watch it in motion!


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## jbesowest

Good thought. I am just finishing up a model Bremen Walking Beam engine and it also has a pretty substantial closed system construction. I have always been a little concerned about water leaking into the "boiler" displacer cylinder, but never considered making a "bomb" out of the engine. I believe that I will install a safety valve.

Thanks -- a beautiful job on that engine.


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## hvirtane

Hi, 

my Friend just bought a factory made quite similar engine. 

It is available here. 

http://www.hyporex.ca/big-stirling.php

It seems to be good. 

---

I think that your 2X size engine should be tested to find out how much power you can generate. 

If run by solar energy, using concentrating mirrors, and burning wood, it could make a way to generate electricity in remote areas and in developing countries. 

---

Has anybody tried to combine several engines like this on the line (3-6 cylinder...) to see, if the efficiency could be preserved so that a real home made power station could be developed? 

with best, 

-hv


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## Bob Bailey

"Has anybody tried to combine several engines like this on the line (3-6 cylinder...) to see, if the efficiency could be preserved so that a real home made power station could be developed?"

 
 I saw a triple version of  Dr. Senft's Moriya at the Lake Itasca Region Pioneer Farmers Show several years back.  It did not appear to generate a significant amount of power. Maybe too much friction?  

 At that time they has a building dedicated to hot air engines.  Some of the engines probably weighed close to a ton.  One Man, Olaf Berge, would bring his collection of full size engines.  He and his wife would have them all operating for the whole weekend.  Incidentally that show is one of the best I have been to.  The 600 mile trip just got to be too much for me to drive now, plus my grand-kids are all grown-up so I would be going by myself.. Here is their web site http://www.itascapioneerfarmers.com/index.php


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