Rogruth, excellent questions, and... I don't know. Maybe Hev will, when he checks back in.
More on the show. ANG mentioned hit-or-miss engines. They were everywhere at the show, running every conceivable implement:, saws, planers, cement mixers, washing machines, stone crushers, corn shellers, feed grinders, ice cream makers, well water pumps, DC generators, you name it. What a boon these must have been to rural Americans in the early 20th century, where for most of the country, no electrical power grid was available, and work had to be done by hand, and after sunset came darkness.
These are single cylinder four-cycle gasoline engines with heavy flywheels to carry the momentum, (and pulleys to allow the work), but they have a governor that allows the engine to fire only when the RPMs drop. The result is a *thump* after every 4 or 5 revolutions, and it creates a 'beat' that is both intriguing and pleasant to the ear. They work like f-ing plow horses, too, and never get tired or need feeding. You get in the middle of a bunch of them, and the syncopated chuffing, clicking, and whumping is extremely hypnotic. A tape of this would make a very suitable thing to play in your kid's nursery to get him/her to sleep!
You'd have to hear one of these to have any appreciation of what I mean.
This is a horizontal cylinder. Notice the 'cooling' system, the box atop the cylinder. Water would circulate through drillings around the cylinder and through the head. Hot water in this box, adjacent to the cylinder, would then rise and release it's heat to the open air, creating a thermal circulation system of the utmost simplicity.
Notice the carts. A farmer could pull these anywhere on the farm that he needed it's power.
This one was more developed, and had a water pump driven off the crank. The water was then delivered to the conical screen on the galvanized tank on the far side, where it would shed it's heat as it ran down the screen and into the tank, with cool water drawn off the bottom for recirculation. A rudimentary radiator, of the utmost simplicity!
The ignition was fascinating. The intake valve was locked closed (to save gas), and the exhaust valve locked open (to prevent compression from slowing it down), until the RPM drop allowed the valves to operate and fire a spark, after which they were mechanically locked-out again!
Beautiful old cast iron. The art of the forge!
