Is this round two of the ecent long running `rolling a 172 thread`? - lets hope not. I have not flown a Rallye or read the POH so have no idea if rolling is even permitted. However I do know they are very prone to corrosion and that I have never heard one being described as even semi-aerobatic (like the Beagel Pups). So I recommend that you ditch the idea promptly and rent something designed for the job until your aquisition plans come to fruition. I am assuming that the POH makes no mention of `rolling` or you would not be asking the question on here.