Adding to Trumpy…
When you use Constant Quality file sizes can vary wildly.
One reason could be the film has a lot of grain in it and Handbrake will attempt to capture each grain dot and reproduce it perfectly. <—in a file about 20gigs…lol
Here you go - start here and adjust as necessary:
3750Kbps will give you sizes at about 1.5G per hour.
That rate in a 2 Pass encode - using my settings above is MORE than enough for most anything - certainly for Black and White.
Personally, 2650Kbps is plenty for me, but you’ll have to use the eyeballs in your head 'cause mine won’t work for you…