Why does the gas engine have to have & balance wheel if the Stanley engine does not?
To absorb and smooth out the sharp explosions, and steady the turning of the shaft. In addition to this the heavy balance wheel carries the gas engine over the three idle strokes, one of which is the compression stroke, which would otherwise stall it. The Stanley, on the contrary, exerts a continuous pressure. This pressure expands, instead of exploding, and does not have to swing a heavy weight to turn the shaft smoothly. And there is no compression stroke to a steam engine, nor is there any “stalling,” so a fly-wheel would be superfluous.
