Light weight Euro-diesels

wrote

The other possibility would be to stick a radiator in each wing root
and funnel ram air through the radiator into the wing cavity. The
warmed air would then be the heating element. I wonder if that would be
sufficient to prevent gelling and also provide some minor wing heat
without all the complexity.

You really need to take some physics and thermodynamics. Right now, you
need to buy a vowel.

I'm only kinda kidding. What you are proposing isn't being done, because it
won't work. Sorry.
--
Jim in NC