There's an old noted tale about these manufacturing ability that illustrates....to the question "what tolerance can you work to ? " the answer given was "what tolerance can you afford Sir"

It's certainly in the Japanese technical psychology to just keep pursuing those improvement in development, manufacturing and product resulting from those process.
Whats not even now aknowledged, and in the light of thinner oils being used in current engines to general disbelief....comments like "how can it possibly last long running on that thin an oil ? pfft, you'll not catch me using that stuff, I'll run it on 20w50 " when in reality these Honda engines, even in the sixties are specified and toleranced to run on straight 20 viscosity at ambient temperature up to 60 F and 30 viscosity above that. They were that far ahead in manufacturing tolerance right from the early engine.