[hinkley]

What I’m saying is, should we still be building engines that rely on “the” head gasket to keep fluids separate?

An engine cylinder at a minimum must deal with: lubrication, fuel, and gasses. The exhaust manifold deals with half of the gases. I can’t recall if common rail injectors are still technically part of the head (I can find pictures where the CRI system sits on the head, with separate gaskets, but I’m not a mechanic).

With modern manufacturing would we not be better off splitting these tasks up so that only a cracked engine block can mix fluids. Not a torn gasket, not a warped head, not a thrown rod (though rods are going away too).