Low idle oil pressure
I am wondering if anyone around there has any ideas about an oil pressure problem I have been having. I rebuilt a 350 chevy engine in about 1998 and it ran flawlessly for years. Then I had several problems very close together. It became very difficult to crank when it was hot. It reached a point where if I turned the engine off, it would have to sit for 30 minutes or more before it would even turn over. During this time, I replaced a bent a pushrod, and a couple months later, a seized lifter. At this point, I noticed that my idle oil pressure was low, so I decided it was time for a rebuild. I pulled the engine out and went completely through it. I replaced everything that I new of that could cause an oil leak: new rings, new bearings, a new oil pump, a new (longer duration) cam, and lifters. The pump is a Summit piece that included a welded on pickup and new pump shaft. The cam is a CompCams XE274H with matching lifters. I also checked all of the oil galley plugs and they looked fine. However, after getting the engine back in the truck, I still had the same problem with oil pressure. The engine produces great oil pressure cold (over 50 psi at idle) but only about 7 psi idling hot at about 700-800 rpm. I took the valve covers back off to check the preload on the lifters and found that oil was spraying out of the rocker arm on #1 cylinder (a steady stream against the fender well). It drenched the side of my truck before I could shut the engine down. Does this mean that another lifter has seized or is it just a result of the low oil pressure? Considering my relatively good oil pressure when cold, would a high volume oil pump help the problem? Do you have any ideas about the root source of the problem?