Mr. Know It All: VALVE TECH

Dirt Bike,
I was going through some old articles recently and came across your announcement of Honda’s Spherical Valved Engine in your July 1990 issue (pg 55). That design seemed to have a lot of promise and would be even lighter and smaller than today’s 4 strokes. Any idea why Honda wasn’t able to get this idea into production?
Delane Maddy
Oak Hill , WV

We have reprinted the story exclusively for our website. Honda has so many designs floating around it’s hard to figure out what happened to this one, but it was interesting. Instead of traditional valves, the motor used what amounted to big ball bearings with tunnels through each axis. The balls would align with the ports, then rotate to close the opening. We suspect that carbon build-up would prevent an air-tight seal, and that might have been the reason we haven’t seen it reach production.