Some good information there Scheny. Looking at the Gates GT3 tables, if the engine hp and rpm fall outside the range on the table for a belt does the belt normally fail catastrophically the first time it hits full power, or does it just need to be replaced sooner than normal (for instance at every 100 hourly/annual inspection)?The best belt on the market at the moment is the GT3. It has superior power capability and in addition higher lifetime, still it is limited to where it can be used.
Belts are categorized in pitch, meaning the length between two teeth, and width. The 8mm pitch is limited to 5500rpm and the 14mm is limited to 4000rpm (on the smaller gear!). In terms of power, the 8mm would only handle 200hp at maximum width, so it would be wise to use the 14mm in the first place.
The values can be exceeded for short time (if other parameters allow it), but at this deviation I don't see how you could put this in your aircraft (at least not for the 2x200hp version).