You may want to take the approach of using WorkspaceRunner  as master workspace.
On the workspace you already have, expose parameter path of the reader so it can be feeded externally with paths sent from master Workspace.

fme WorkSpaceRunner will fire a workspace for each, you can even run 8 in parallel or run one by one.

also i suppose the reader "Directory and File Pathnames" will be very helpful for you to create the path/filename to be sent as argument to your translation workspace from the workspace runner.

some more info can be found below.

http://fmepedia.safe.com/articles/Samples_and_Demos/WorkspaceRunner

https://www.youtube.com/watch?v=djeMx1j1R7I

http://gis.stackexchange.com/questions/30176/how-to-read-files-one-by-one-with-fme

hope it helps.
Good luck.