How do you know when something's a genius invention? For me, it’s when I see it and instantly go: why didn’t I think of that?

While the poppet valves work well at low speeds, they are unreliable at high engine speeds, and the “timing,” or opening and closing of the valves, is uncertain. This is the gravest objection ...

Knight subsequently began experimenting with ways to supersede the poppet valve and, in April 1904, filed a patent for a new type of internal combustion engine. Instead of using poppet valves ...

However, spool valves usually have higher flows than poppet valves within the same footprint. This is because a poppet valve needs a large poppet area to create a large enough shifting force to ...