Any appreciation for what might be the closest "modern" attempt to effectively replace the VW Beetle?

[freebeard]

I enjoyed, and still have, an aftermarket five-speed conversion. With a conversion from swing axle it would happily live in my Superbeetle.

Cheap/simple: Unpainted stainless steel body, flat glass, ceramic engine block running at high temperature.

[cRiPpLe_rOoStEr]

Originally Posted by freebeard

Unpainted stainless steel body

That would be quite interesting, yet if I were building some sort of Beetle replica I would nowadays be more inclined to use some fiber-reinforced plastic.

ceramic engine block running at high temperature

Just the block made out of ceramic? Well, maybe some water-cooled heads such as those fitted to some engines adapted for usage in ultralight aircraft could be interesting to decrease NOx emissions.

[freebeard]

Offenhauser built monobloc engines from 1930, no separable head.

Porsche 3D prints pistons with internal oil cooling passages.

I believe high operating temps benefit the thermodynamic cycle.

[cRiPpLe_rOoStEr]

Originally Posted by freebeard

Offenhauser built monobloc engines from 1930, no separable head

Avoiding head gaskets, which are prone to damage, is a good thing. No wonder Citroën resorted to threadable cylinder heads for the 2CV for instance, even though it was not so similar to the monobloc Offenhauser. But I guess it would be a PITA to overhaul a monobloc engine, or just replacing the valve seats or guides.

[Piotrsko]

Except that the head doesn't remove, the valves either come out the side like a "F" head or out the cylinder with the pistons gone. I know the offy was a "F" head for a while. A "T" head would be interesting.

[cRiPpLe_rOoStEr]

Overhead cams seem to be the best solution for a monobloc engine.