Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Walt,
That's the main issue with both Schoenner and Paradox engines. They were made to run on illuminating gas/town gas which was at one time piped into homes for lighting and other purposes. This gas is quite different from any of the modern fuels including propane and acetylene. So the engines require a custom mix of propane or methane and hydrogen. Some of the larger shows here in the US purchase truckloads of this mix for running their early flame ignition, slide valve engines like the ones shown around the Schoenner in the video. So if I want to run the engine I just take it to one of those shows. They could potentially fill an empty propane tank with the mix for me, but because it cannot me compressed much without affecting the mix, that tank would probably only last a couple hours at most. Would love to know if others have found mixtures that work.

The video showing above was posted by Carl Swanstrom of Naperville, IL.
Sadly, about Carl called to let me know he would not be around long due to lung cancer from a life of heavy smoking.
This was late 2008.

We visited him late one evening when we were traveling in the area and got a first class tour of his collection.

His gas mix is near identical to "illuminating gas" also called "street gas".

EDIT: It is not near identical but does the same job and maybe a bit better as illuminating gases were about 50% hydrogen and had a few other components. I learned this just now checking in Wayne Grenning's book on Flame Ignition Engines.

For a number of years Carl's video was the first and only one of a working Paradox engine.

It is:

70% hydrogen
20% methane
10% carbon monoxide

This mix can hold well in a pressurized cylinder and it requires a special one. Hydrogen molecules are tiny and can weep through any but the least porous metal container.

Carl had a small bottle and batch mixed. Ronald McClellan also has a similar mix for his Forest repro by Wayne Grenning and for his Schoenner gas engines.

At Coolspring Wayne meters the hydrogen and propane at about an 80/20 mixture which works well on most engines. His regulators allow him to change the mixture as needed for specific applications.

Thanks Gil. That's one possible mix; the mix used at Coolspring Power Museum contains propane and I can get the exact formula if anyone is interested (just send me a PM). The problem is you can't pressurize this mixture over 100 psi or the propane will condense and the mix becomes adversely affected. If I'm not mistaken these gasses are kept in separate tanks and mixed in the correct proportions as they enter the engines' fuel stream at Coolspring. Propane that you buy at your local store is stored as a liquid at 100-200 psi. So the amount of this gas mix stored in one of these tanks at less than 100 psi won't last long even for a tiny engine like mine.

That's right, Brent. Wayne keeps them in separate tanks and with his precision mixing regulators he delivers into on pipe or tube at 80% Hydrogen with 20% propane. In addition, with his set-up, these percentages are infinitely adjustable so he can fine tune a mix to a particular engine when needed.

With the hydrogen, methane, and carbon monoxide I believe you can compress it nicely into a single bottle and that bottle purchased empty can cost many hundreds.

Wayne has also worked out a way to start a larger flame ignition engine and warm it up with the hydrogen straight or as an 80/20 mix. Once it is warm, he has been able to leave pure hydrogen on the pilot flame/flames for the ignition and switch the operating fuel to propane. This saves considerably as a large engine can burn a lot of expensive hydrogen. This works on 4 cycle slide valve engines but not well on non-compression engines.

If you have Wayne's Flame Ignition Book on Internal Combustion Engines, in the beginning, page xiv and xv have tables of illuminating gas composition by region and heating values of engine fuels in BTU per cubic foot and BTU per pound.

Now I'll edit my other post on street gas!

Hi Brent. Hundreds of dollars. I think Carl spent 300 for a small bottle and I believe Ron McClellan spent 800 for a lager bottle. They are made of the highest grade aluminum. The $800 plus Ron spent covered the tank and a special valve and regulator designed specifically for small molecule gases. They are compressed into the tank at about 3,000 psi. Many of these engines including the large slide valve Otto engines run on very low final pressure that is measured in miliounces, ounces, or inches of water.

To get his tank filled, he brings it to the local industrial gas supplier. They in turn, ship the bottle to a facility that can handle custom gas blends. They inspect the tank and valve, then blend and fill. They charge Ron $200-300 for a fill up. This is not a cheap fuel supply...!!

Propane liquifies at low pressures making it ideal for outdoor grills, home cooking and heat. Because of this it is cost effective.

Methane mixes well with hydrogen and will not liquify until over 4,600 psi is applied (vs 100 psi for propane)

Carbon monoxide will not liquify under any pressure to my knowledge. Like carbon dioxide, it can be solid as in dry ice below -109 F (-80 C) but will sublimate and exist as a gas at any pressure with temperature above minus 109 F.

Gil

Thanks everyone for all information supplied herein, it will take me a while to digest it all.
Seems like I will need a hydrogen generator somehow; that should be fun.