Quench?

I saw siomething on the History Channel about that (WAYYYY before my time...lol), and yeah, they "tuned" the engines manually on the last piston powered planes. Altitude will change the burn, and even now, the guys running Avgas, are using a fuel that's not formulated for sea level use...lol. It's hard for me to visualize it in real time. It's easier saying "slow" vs "fast" but we're talking hundreths of a second. It's easy to "freeze frame" the motions and angles at any one degree. It's entirely another to map out a burn characteristic.. but they do. Must make for a long day...lol.