The discussion here is regarding a hardened oil pump drive shaft or not, but the discussion is germane.
quote:
The whole crux of the problem is the Ford oil pump, its a gear rotor type pump, which puts out a smoother flow of oil than a gear pump like those used in a chevy, but the draw back is the Ford pump does not pass debris very well. It tries to lock up and stop turning.
The stock Ford oil pump drive shaft twists very easily. It is not unusual to pull a motor apart and find the stock oil pump drive shaft with one or two full twists in it! But the little roll pin never shears.
The fear is that the oem oil pump drive shaft will snap in two, so all hot rodders & racers replace the stock oil pump drive shaft with a heavy duty unit. The heavy duty drive shaft doesn't "give" when the oil pump passes debris, so the oem roll pin shears instead. This is not just a Cleveland problem, it is a Ford problem in general, as all the V8s employ a gear rotor type oil pump.
Ford didn't design the roll pin to shear, but they did design the drive shaft to deflect (twist) intentionally, so as to allow the oil pump to pass debris. When we smart hot rodders replace the shaft, we defeat Ford's engineering.
The nice part about the roll pin shearing is that the distributor stops turning, the motor stops running, and there is no damage to the motor.