Sorry I don't build to plans, but I do have a couple of James G. Rizzo's books, bet to get hold of his "The Stirling Engine Manual" vol 1, and if you take up Stirling Engines try and get vol 2. It is also worth down loading Andy Ross,s book "Making Stirling Engines"(free down load), no plans in this book, but plenty of information.

First a stove top fan, 30 mm bore, 20 mm stroke power cylinder.

Second, a little beam engine 3/8" bore, 1/2" stroke power cylinder, the hot cap is the steel casing of a AA size Nicad battery.

There is about a dozen more motors, you just need to have the correct dimensions and ratios, and a bit of imagination.

Go for it, and good luck, don't be afraid to ask questions.

Ian S C

That requirement put me off building that sort of Stirling engine Mike. The main reason for stainless is its thermal properties with good cosmetics scoring extra brownie points.

Stirling engines work best when the hot and cold ends are well insulated from each other. As it's the temperature difference than moves the piston, heat leaking through the metal tube from the flame to the cold part reduces the efficiency of the engine. As small engines are marginal this effect is best avoided. Metals like Copper, Silver & Aluminium conduct heat better than mild-steel, and mild-steel is about 3 times more conductive than stainless. That's a significant difference!

The other requirements that put me off stainless, were 'No Leaks' and 'Minimise Dead Space' Even a tiny air leak at the hot end will stop the engine, and the design I looked at recommended welding. I thought about crimping the end of the tube and sealing it with solder but a crimp (I think) increases dead-space, whilst soft solder won't stick or take the heat. Not sure about silver-solder.

Alternatives to stainless include ceramics and large Pyrex test tubes, which have their own problems.

Anyway I chickened out, and built a CoffeeCup instead! But people do build your type of engine and one of them should be better informed.

Dave