All the literature I've read for bodybuilding says your reps should be in the 8 to 12 range, and higher reps leads to more muscle endurance without much muscle growth.
So you're looking at (4x1.5+4x1)x4x2 = 80 minutes == 1 hour 20 minutes minimum. Without counting the time to move from one exercise to another, without changing your clothes, without falling into a conversation with a fellow gym member, without waiting for anyone to free up a machine/weight-set/whatever.
Face it, if you're bodybuilding you're spending 2 hours a day at the gym.