Re: V8 oil Pump ID?

Posted by PackardV8 On 2012/3/4 21:30:03

Yes. As BH indicates above the FIRST gen Packard V8 oil pump used a relief valve that resembles the Olds relief valve. The SECOND gen Packard V8 pump (with PLUGGED port) used the relief valve that Craig has pictured above with a recess cut about mid way.

But the INTERNAL cavity allowing for recirculation of over-pressured oil of the first gen pump differes greatly from the second gen pumps cavity also.

So there is a difference in the sliding relief valve AND a difference in the internal cavity between the two different pumps.

Edit: Just for clarity note that ANY packard/hash or 56j oil pump RECIRCULATES over pressure oil INSIDE of the pump. More specifically let me state that the over pressure oil is NOT dumped out of the pump. The over pressure oil is RECIRCULATED back thru the INTERNAL SUCTION side of the pump.

I'll even state it a third way:
Once oil enters the pump there is one, exactly one and only one exit that the oil or any oil that enters the pump can exit. That exit is thru the neck of the pump that bolts to the rear main bearing cap.