Jim Cameron wrote: Biggest problem so far is that when I first fired up the engine, it took a very long time for the oil pressure to come up.  After draining it yesterday and re-filling it for its first oil change, I can't get any oil pressure at all.  I've never had this problem on my factory new IO-550's, and a couple of A&P's I talked to today tell me that no way should it be doing that.  Yes, I could perhaps take the filter back off, prime it with oil, and try again.  That would still beg the question:  what's wrong with the oil pump?  Any ideas, any of you?

I would be suspect of the oil suction tube being cracked or loose at the pump.
Craig