low oil pressure

[fourohsicks]

I recently pulled a motor on a 2000 Z.It was knocking.I tore the engine down to discover the bearings were not that bad,only they fell right off the saddles.By saddles I mean the rod and main saddles.They were dark in color and a few had light scuffs.We decide we were going to reuse the crank and pistons.I honed the cylinders with a ball honer once it was returned from the machine shop where they replaced the cam bearings.The machine shop checked the crank and polished it.I replaced all the bearings with new standard bearings clevite77.New rings, oil pump, timing chain,and gaskets.New high lift and duration cam.torqued and degreed all main and rod bolts.I installed the lifters with the oil feed holes facing the oil galleys,bolted up the heads etc.I did notice the push rods were a little too short.Upon fire up,I noticed valve train noise.I told the owner he would have to replace them.He drove the car for 2 weeks and told me the oil pressure was low.All the way in the red he said.When he first starts it it is fine.Then it warms up and the oil pressure drops.He is using 10/30 royal purple.I installed the O ring correctly.For the most part I assembled the engine correctly minus the pushrods.I believe the machine shop didn't do a good job on the crank.Excessive bearing clearance?What do you think?

[Danger731]

clog in the pump ?

[fourohsicks]

We replaced both the pump and the oil sender.Ran the engine with the passenger side valvecover off.Oil barely squirted out the rockers?Someone told me the pushrods being short is not putting enough preload on the lifters...causing the oil pressure to be low???