70 cc stirling drives buggy.

[Aviator168]

It is not slow at all for a buggy with a stirling.

http://www.youtube.com/user/caloric16

[vile_fly]

Ha. Neat. Not bad at all. 105mm (4.133") bore, 70mm (2.756") stroke. I just wish I knew if it was pressurized or not. My guess would be not pressurized.

[Aviator168]

Not pressurized from his email. He needs to get a better and small heater and cooler. If pressurized to 5 to 10 bars, I wouldn't surprised that it can power a fast go cart.

[onecycleDan1990]

math error, decimal error, or typo: displacement eqn. is identical to volume of a cylinder, the bore being the diameter and the stroke being the length.

((bore/2)^2)*pi*stroke = ((10.5cm/2)^2)*3.14*7cm = 605.8 cubic centimeters = displacement of engine in question

look at the size of it, it looks a lot bigger than any 70 cc engine.

perhaps a reading error, the stroke is stated as 70 mm in the video.

according to youtube comment it produced 100 watts in the test shown and 180 watts with a new heater and pressurization to 10 psi. many unpressurized air engines have put out 1/2 to over 1 watt per cc, so this engine is impressive primarily in size and perhaps complexity, given its rhombic drive and finned heater instead of power produced. Even so it is very nice to see someone building something bigger than a tabletop toy and 100 watts from any homemade stirling is something worth bragging about.

I also wonder as to what burner was used; the hot cap of an engine of this general type should be red hot over a large area.

With less dead space and large improvements in heat transfer I would not be surprised at a 400 to 700 watt output.

[Aviator168]

Yes. It is indeed about 605 cc. A lot bigger than 70 cc which I mis-cal. However, with 10psi pressure outputting 180w, that only put it 0.298 watts per cc. A lot less that most of the unpressurized stirlings out there.