If you're looking for good picts to study, I wouldn't recommend looking at someone else's paint job of realistic flames. You'll just end up with a paint job that looks like theirs.
Go to Google.com and do an image search for flames or fire. It'll bring up quite a few examples of realistic flames for you to study. Take a look at quite a few of those and then go paint your own set of realistic flames, not someone else's.
-Stretch