Quote Originally Posted by Hans Pearson View Post
A fascinating concept, which I have been thinking about for some time, and then I saw the proliferation of these engines on the internet. I am building one at the moment and am stuck on the valve systems I am throwing around and trying to work out something slightly different from the usual, ie. the one shown on the version in the video. I am also looking at making it liquid cooled as these engines become less efficient and eventually stop as they heat up.
Valving on these engines can be very tricky. It needs to be quick and thorough. My engine uses a piece of shim stock as the valve. It's thin enough that, as soon as the vacuum starts to form in the cylinder, the valve is sucked down onto the cylinder top to form a good seal. I have another flame-eater that originally had a sliding bronze valve. It never worked very well until I replaced the bronze with shim stock.

My engine runs for long periods without the need for external cooling. The cylinder fins seem to do the job. Remember that the cylinder must stay fairly hot lest it quench the incoming hot gas too quickly before the valve shuts and the vacuum starts to form. Water jackets are great for Stirling engines; I made one for my Ringbom...

http://www.homemadetools.net/forum/l...8339#post68963

but I question the need for an atmospheric engine.

Regardless, it's your engine; build it as you see fit. The fun is getting it to run. Nothing beats the excitement of seeing a homemade engine run for the first time.