Originally Posted By: Trav
The more I think about it this would be great if it can be made reliable, no belts/chains, tensioners, cam shafts, lash adjusters, VVT systems VCM components, etc.
Those timing chains also consume some power (friction), so that is factored in to the overall energy efficiency of the entire new system as well.
On replacement costs, remember labor is a big part of it all, and these actually seem like they could be a somewhat easy, quick fix if one goes bad, pop the old one out, new one goes in.... DIY very possible.