Schoenner engine details

[Mick BaileyParticipant @mickbailey28509]

I recently came across the Schoenner patent for a toy gas engine and thought it quite interesting. Some of the models produced at the time were really quite nice, bearing a strong resemblance to ‘proper’ engines.

I’d assumed that the flame port was simply a hole and the engine relied on the surface area of the piston compared to that of the port. However, the patent shows a one-way valve being fitted (though it describes this as being optional) and this would seem to improve operation in that the flame would not be subject to blowback. It occurred to me that a hot tube could replace the port to better effect.

Looking at pictures of the engine I see that there’s a fitting set vertically into the cylinder close to TDC that isn’t part of the head and not mechanically operated – what is this?

 

[noel shelleyParticipant @noelshelley55608]

A non return , very lightly spring loaded to allow air in on the induction stroke ? Noel.

[Mick BaileyParticipant @mickbailey28509]

I think so. The patent describes an adjustable supplementary automatic valve to equalize performance. This is in addition to the mechanical inlet valve. The patent shows this being part of the cylinder head, but at the same time a fitting is shown on the cylinder itself, which is not described. This is in the same position as were the model engines I’ve seen have some kind of device. Maybe those engines have the automatic valve relocated to that position.

There’s a YouTube video of one of these  engines (of modern construction) running for a limited time and from what can be seen it’s a low-revving engine

[JasonBModerator @jasonb]

They run better on the old town or illuminating gas. Have a look at this thread over on MEM, The Schoenner is having a job running on propane but Graham’s leek is going at a reasonable lick on HHO

[Mick BaileyParticipant @mickbailey28509]

I wonder if petrol-air gas could be used in a gas engine as an alternative to town gas. Compact plants were used in Edwardian times as a lighting source. I would expect it to have similar properties to vapourised petrol in a regular liquid fuel engine. Maybe it has a wider ignition range than propane. I have a book somewhere describing in detail how to produce the gas at home.

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