Stirlingengineforum.com

Out of curiosity, has any one made an opposed cylinder Stirling? I searched the forum but couldn't readily find anything. To me it seems like it would be something similar to a alpha, yet the pistons would have to be mounted to the crank at 90° like a beta.

Okay so I should just not worry about changing the ratios. I was already planning to essentially make the displacer slide about the two ends and shave a mm or two from the center section and add stainless steel wire cloth to act as a regenerator. I was also going to make holes to force the air throu...

Hello, I am working on a beta style Stirling, and I am planning on using a 32mm cold end cylinder and a 35mm hot end cylinder. Is there some correct ratio to modify the length/stroke of the displacer by? I know that typically we do 1.5X(Power Piston Stroke) for the displacer stroke, and 3X(Displacer...

Yes I considered it the dynamic shortening of the connecting rod. The thing is I only needed the calculation for the OAL of the cylinder, when the piston is at BDC I don't have to consider that contraction. I was just having trouble knowing exactly how long I wanted the cylinder and where the piston...

Ian, How hot does the cold end of your engine typically get? I ask because I am going to use a water cooled cold end and I have the option to but a single O-ring for 12 dollars or fifteen for the same price, the difference is one can handle 450°F and the other can only handle 250°F. My current desig...

Oh, almost forgot!

-What is a typical tolerance between the cylinder wall and the displacer?

-What is a typical tolerance between the cylinder and piston?

Thanks!

I figured out the piston/displacer position using trig. Now the next questions. -When making a piston for a Stirling I am curious of how critical I need to be with the thermal expansion of dissimilar metals. -Should the cylinder and piston be the same metal? -Do you normally lubricate the piston? -H...

When the displacer is 90° from top dead center is it 50% below the top of it's stroke? I am just wondering what positions to account for my clearances. I don't want to end up building this thing and having my connecting rods too long then have the piston and displacer slam into one another. From the...

I was planning to use some 400x400 stainless steel mesh to contain my choice in regenerator material in the displacer. stainless mesh http://www.amazon.com/Stainless-Steel-Mesh-400x400-316L/dp/B00DRMFWBU regenerator material http://www.artistsupplysource.com/product/53904/copper-wool-pad-made-in-usa...

At what point are the piston an displacer closest together? When the displacer is at BDC and the piston is at half of it's stroke? I am just trying to get the connecting rod lengths and everything designed so that I can have the motor practically done with the design phase, save the operational tole...

Okay, in that case I will do what I can to use stainless or iron, but if my only option is aluminum that is what it will have to be. I doubt I will be able to have much influence since I am doing this as a project for credit through my school and the professors are doing what they can to facilitate ...

Well I was thinking about casting the hot cap and then machining it to spec. Same deal with the displacer. I know I had mentioned it before but I was planning on putting the regenerator inside the displacer. After more research I have found plenty of gaskets that would handle operating temps. Also s...

It looks like I am going to be sand casting as much of this as I can. Hopefully I will be able to make it from iron but that depends on what will be available in the program I am working with. The professor I will be working with wants me to keep the cast parts small, so I am thinking about casting ...

Thanks! My mistake I should have remembered that. I read somewhere that have a square stroke is a good balance between rpms and power which is why I went that direction. My brother was under the impression that an over square stroke is better for producing power, is that true or should I keep the sq...

Minimum dead space also means minimum working fluid which is the important part of the engine. It would likely just be added complexity to make a somewhat modular unit for the purpose of testing. Though that might be a great way to empirically test the system and see what changes have a positive eff...