lol, this is hilarious... starting to wish I hadn't subscribed to this thread, my inbox is full of "hitman_214th has replied", "corsair7662 has replied", "hitman_214th has replied" etc...
Anyway, thanks to the initial posters, I will follow up on those sources for sure (I'd seen breif engine info in the back of Jane's all the world's aircraft but never thought to look for a volume on engine's alone). CrazieAggie, if you come across those white papers again let me know, I've searched but haven't found anything yet. To Brit, thanks for the suggestion on the J-58, I have the option to change the engine I'm focussing on up until the due date, with the information you passed on it's definitely a viable alternative.