[elbucko]

At any rate, the amount of hardening on high load surfaces, expensive metallurgy on a valve train, probably make it very expensive.

I agree. It seems to be a reinvention of the wheel.

It would be interesting to see and hear one running though.

Yes it would.

[-YYZ-]

Yep, the usual achille's heel of unconvential IC engine designs: parts, materials and manufacturing techniques that are either non-existent or extremely expensive. Too much so to overcome the inertia of conventional designs.