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

I've come close to the frequency shown in that second video, but the first video is a whole level of magnitude beyond what I can even conceive of at this point. It would be nice to know what all has been done to that one to get it down to that infrequent firing regimen. That is just how I'd like to get mine running someday!

Same here on the way mine has run Stoker. I reckon mine had a firing pulse about once every second when I temporarily removed one of the governor springs. I also stretched it just a tiny bit as well, which helped. I know this is not good practice to have a spring on only one side, but it was just an experiment.

As for how the first engine still runs with so few ignition strokes, I think (just guessing) that the owner must have reduced the compression ratio somehow. Mine would certainly stop before TDC on a compression stroke at that speed, because the energy in the flywheel would not push it over the peak compression point. That would require some machining of the piston and a degree of daring. Would it still run after, or would you have to make a new piston? I know some skilled people have taken about 10 thou off the top and also dished the piston. I don't have the machines to do that and would not try it myself.