Don't know of any real film clips. There used to be a good computer video online, but it is gone now. However, check out this place. It has computer simulations of a whole bunch of different valve gears and you can vary the cutoffs and other things on them too:http://www.alaska.net/~rmorris/als2.html
.
This is a very good simulation
http://www.youtube.com/watch?v=dlSp94dTwNU
I think Southern Pacific 745 (Mk-5 class 2-8-2) has Walschaerts valve gear. My video of the wheels and valve gear showing a slow-speed run-by is here:
http://www.rail-videos.net/video/view.php?id=615
However, you may well get something more like what you are looking for with the videos Ritchie Jacobs posted on YouTube. He likes to mount video cameras using poles and stuff, and has posted clips showing close-ups of the rods, valve gear, etc. in action, from a locomotive-mounted camera. I can't give you a direct link, but I know the videos were out there. Try searching on YouTube or maybe for a link at SP 745's operator's web site:
www.lasta.org
Login, or register today to interact in our online community, comment on articles, receive our newsletter, manage your account online and more!
Get the Classic Trains twice-monthly newsletter