[aerohead]

If you look into tribology, the science of lubrication, you find:
1) Engines rely on hydrodynamic lubrication.
2) Sliding and rolling surfaces are all separated by a film of oil.
3) The 'friction' is caused by hydrodynamic viscous shearing of the oil.
4) It's a 'viscosity' issue, just like aerodynamic surface friction drag. True for all non-ideal' fluids.
5) You could 'Teflon'-coat , or coat with anything else, till the cow's came home, and it wouldn't change a thing. Your solving a problem that doesn't exist.
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6) The only thing which is 'known' to reduce engine 'friction' is 100% synthetic engine oil, of proper viscosity. Synthetic oil is actually of lower viscosity than it's API label rating, however, it's against the law for it to be advertised as such, do to a quirk in the law. It has a lower temperature pour-point, requires less cranking power. It is virtually ash-free. At extremely high temperature it still maintains a film strength associated with it's rated 'weight' because of extremely robust long-chain designer molecules.