I assume your talking about VCD's and using DVD2SVCD to make them?
2hr 12 min is 132min long, then set the CD size to be 1/2 that x by 10 ( 1min = 10meg) + a bit for elbow room. So it would be 660, so I would set 670 as CD size.
As I've said before, just cut the movie time in 1/2 & multiply by 10 + a bit.