[911monty]

This IMO is a hold over to american engines. It was and is a very good practice IF it can be done. American iron such as chevy had the ability to remove the distributor drive shaft, grind the cam drive gear off and use the shaft to spin the oil pump, WITHOUT spinning the motor over. This pumped oil through the galleries to the rotating assembly bearings, crank, cam and piston rod and finally to the valve lifters. This ensured an oil film to all components before firing the motor.
Unfortunately this is not possible with the Porsche motor. To prime the Porsche motor you have to spin the rotating assembly with the starter until oil pressure comes up. The downside to this is the pistons have now travelled up and down their bores dry. This introduces greater wear to the rings and bores of the cylinders. In fact some manufacturers do this to seat the rings on a new engine.