You can crank longer than 10sec and i would reccomend doing so i would say 30-45sec the only problem that can arise is overheating the starter longer than 60sec i advise against and about 10sec inbetween 30sec cranking intervals the problem with short cranking periods is the needed pumping cannot be accomplished at the 200-300rpms when cranking as the pump has to pull oil up, through the pump, and to the filter where it will turn off the dummy light and STILL has not reached any bearings and when you stop cranking it looses any pressure it had so your just starting from where you began