Betrothing with a loan does not work - but why not? What is the rationale for the mechanism not bringing about kiddushin? Perhaps the loan itself is never really considered owned by the borrower who would use it for kiddushin. Plus, how she feels about the sum total of the betrothal and the need to scrounge for it can have impact on whether the kiddushin takes effect. Also, Rav's view on the loan not working for betrothal. Plus, a disagreement over a loan that has not yet been spent. If it hasn't been, the lender can recall the loan. But is that really acceptable?