K-36 for MS Train Sim

There is a high quality 3D model being made for the Microsoft Train Simulator! Another guy has developed 3' track to use in the sim. I'm doing the sound files. This will be freeware. Here's a link to the post on the train-sim board [www.train-sim.com]
I'm trying to come up with good audio clips of the exhaust sound from a K-36. I need clean recordings with the same general tone (one coming, and one going won't work due to doppler pitch shift, for instance). I only need about 10 or 15 seconds of each, but for several speed ranges. If I could get roughly 2, 5, 10, 15, 20, 25, 30, I can modifiy them to fit from there. I've changed the way the sim uses the sound, so it is much more accurate than what came with the sim. I already have the whistle and bell done. In the end, I'll only use 4 chuffs for each of the files, but need a few in each speed range to pick from. The files will end up as 11,025 Hz, 16 bit mono, so don't need to be super hi-fi!
Any help would be appreciated! If you haven't checked it out, the train sim can be awesome.
Steve