As TimD already stated, some FAI pylon racing engine manufacturers use ceramic ball bearings. For instance the dominating F3D pylon engine - the Dutch MB .40 - is a true masterpiece featuring lots of refinements making this engine apparently unbeatable.
It is a very nice example of the "reduce moving & non-moving parts approach".
It handles rpms up to 35K without probs - and this is a 6.5 cc engine! Keeping in mind those engines run only full throttle ceramics seem to be a good choice in this particular rpm regime and application.
http://home.kabelfoon.nl/~fiorimet/Index.htm
View chapter "Crankcase"
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