Why did the "Normal" valve win? Poppet valves vs. Sleeve Valves vs. Rotary valves.
Podcast:Cycle World Podcast Published On: Wed Feb 25 2026 Description: There have been many engine valve designs since the dawn of the internal combustion engine. What made poppet valves stick? (See what we did?) There were many other designs and some, like the sleeve valve in the Bristol Centaurus WWII radial aircraft engine, that worked very well. Classic Kevin Cameron stuff here as he and Mark Hoyer discuss the relative merits of engine valve types.