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Hi, this would be my first project in the world of Stirling engines. I am thinking a V type alpha would be a good start especially if I dont build it so small that precision engineering becomes a challenge.

What I have in mind is a free standing wood burning stove with a vertical hot cylinder and water cooled horizontal cold cylinder. Cylinder bores will be 75mm (3") or more.

It would be good if this machine would, firstly, run and secondly run well enough to turn a barbecue spit!

Hi John, Don't try to get away with low accuracy, the better you build the better the motor, but the bigger motor will not be as fiddly as a small one.
Don't get the stroke too long, ie for the 3" bore, I would try 2" or 2 1/2" stroke, keep the weight of the moving parts down as low as you can. my way of making pistons, I use cast iron, turn the blank roughly to size, weigh it, hollow it out, weigh it, look at it, think I can take off some more, weigh it. The skirt gets down to 1 mm to 1.5 mm thick, and the crown 2 mm to 3 mm thick.
My ALPHA motor is in my gallery, it's a Ross Yoke type, I suspect it may need a rebuild in the next year or so, think it needs the bearings beefed up a bit, might just build another from scratch. Ian S C

John Hill,
There was one on U-tube, I remembered. But as I reviewed it, it didn't look practical. He had an external stirling engine with it's own heat source. driven by a belt.

Ian, I have found cheap(ish) cast iron plumbing end caps in various sizes which might be suitable candidates to become pistons!!

John, you'v just got to get a nose for hunting these things out, demolition yards, second hand shops, junk heaps, the best place used to be the rubbish dump, but they have sorted that one out. The pipe caps might be just the thing. The motor in my gallery labled my second engine has a power cylinder made from water pipe, bored out, and lapped to the piston, it's over 20yrs old now, and going just as good now, as it did then, maybe better.
Ian S C