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

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.