Since you are planning to "scan" rather than merely typing a sentence or two as "fair-use" quotes for commentary, your term "quote" does not apply. By all normal copyright laws, you are apparently planning theft. Otherwise, why worry about Google.
Yes, you will get nailed. Stealing content written by others, just to feed it to GoogleBot, should never be rewarded.
The fact that it is not in Google Books likely have no impact. Google is likely to have many more books loaded in their databases than the ones showing publicly on their Books site. The publicly viewable Google Books is merely what they have deemed legally "publishable" by them and have flipped the switch for at any given time. You can be sure they will recognize others. OCR'ing books is not a new scam. Google know to protect themselves from that.