i have overhauled a lot of gas diesel engines both 2 stroke and 4 stroke engines.i always ran them in with no water in the engines for the first 5 minutes to get the rings seated.i dont think i would advise running an engine with no oil.non ringed rc engines need to be ran in a little lean to get the piston properly seated.i agree with what springhillflyer said he read about short lean runs for breakin.but not with ringed engines.