Stirlingengineforum.com

[youtube]https://youtu.be/AdojR4QbsTA[/youtube]


Greeting, this a first attempt. I can fabricate all the parts. I have tested the engine with mapp gas and the hot cylinder glows red and the engine shows no indication of rotation. I fitted the system with a air valve and pumped some air into the system but it does not hold pressure. What are some of the methods for making the system air tight?

Displacer stroke, 1.75 inches, bore 4 inch
power piston stroke 2 inches, bore 1 inch

The displacer is wrapped with stainless steel wool.
The displacer leads the power piston by 90 degree.
I sealed all the possible leak locations with high temp RTV silicone, but the air escapes at the displacer rod and bronze bushing at the hot cylinder.

Any suggestions well be greatly appreciated.

Hi, I think the biggest problem I have is the system is not air tight. I cut a gasket using a CNC and I plan to use a flared plumbing brass fitting to try to seal the system.

I was able to pressurize the system to 10 psi. There appears to be a slow leak at the power piston. I will have to install the same gasket configuration at the power piston.

The biggest difference is the increase in system compression. It will need a larger diameter flywheel.

That sealing looks to me like it is going to introduce an awful lot of friction.

Hi, yes. After watching a few more videos on youtube I now know the friction of the system is to high. I have started a rebuild. This is a first attempt and I am just trying to get it to run. Thanks for the input. Searching for ideas to make the system air tight and have low friction. Suggestions welcome.

[youtube]https://youtu.be/LrylX4FZzCM[/youtube]

possible solution for low friction, air tight seal needed for operation

Question about the displacer, if I am fabricating it from a cylinder with a top and bottom plate, should the cylinder be air tight????

Yes.
Ian S C

[youtube]https://youtu.be/6f8vlwrlwvM[/youtube]

Hi, thanks for the info. I have been working on reducing the friction. I still have to add the stainless steel wool to the displacer and seal the system.

[youtube]https://youtu.be/lNaBFt5VW6g[/youtube]

Still not working. I found this project that is using about the same size displacer that I am using.
[youtube]https://youtu.be/s-GX3B14-K0[/youtube]

At this time I think I need a larger volume of air inside the system. Suggestions welcome.

What's in side, what I mean is how have you constructed the displacer?
The ratio between the two cylinders doesn't seem right, it should be, displacer to power cylinder 1.5 : 1.
For the power piston to cylinder, care is required in choosing materials, best is cast iron on cast iron(the only metal that can be run against it's self),next is steel/ cast iron, then a steel piston in a bronze cylinder. After this it goes to graphite piston in a polished steel/ stainless steel, or glass cylinder. Aluminium can be used if it is hard anodized, or Teflon coated.
The larger displacer is used in motors running at lower temperatures.
Ian S C

Hi, thanks for the help. The displacer cylinder measures 4 inches in diameter and 5.75 inches in height. I used high temp silicone to seal the displacer. Power piston measures 1 inch in diameter and has a 2 inch stroke. The displacer has a 2 inch stroke.

I think you'r going to have to redesign the displacer to get the right ratio of 1.5 : 1. The displacer should have a diameter of about 1 3/16" to 1 1/4". Don't worry about the steel wool, make a light weight hollow steel displacer with a gap of about 1/16". The displacer should be about three times it's diameter long, and the gap at each end kept to a minimum, 1/16" would be fine.
Ian S C

[youtube]https://youtu.be/rGFiaL_gYhU[/youtube]

Hi, thanks for the info. At this time I am planning to try to replicate the above project. Thanks again.

New power piston. It looks funny but it moves a lot of air and the system should air tight.