Oh yeah, can't believe I haven't linked this...
http://www.gamefaqs.com/boards/960633-the-legend-of-zelda-skyward-sword/61263712(enemy HP table and damage values)
There are some mild inaccuracies, but for the most part it's quite solid. Helpful for planning attack combos and such, I know I made use of this in several fights (in others though, number of hits is what matters, not damage so this is useless).
For example, you can see that in Hero Mode a skyward strike will do as much damage to Scaldera as attack to spin. I know you have a reasonable amount of time to get some hits in, so you probably should be able to charge skyward strikes and use those while he's stunned too. I can't confirm anything with the skyward spin, but if that gets a damage boost too, you can (in theory) kill him almost as fast as you could in the boss rush.