If this so called "engine builder" told you to change the oil a month after break-in he isn't much of an engine builder!

Myself, and many others, will agree that changing the oil while it is still relatively hot immediately after cam break-in (or 'initial break-in' - semantics) and inspecting the filter is the best procedure to make sure you cam break-in went accordingly.

How would metal being absorbed into the bearings affect oil pressure? The bearings still could have seen enough metal to ruin them over time - it will most likely will not be instantaneous and immediate loss of oil pressure and engine failure but a problem that could snowball if not taken care, but this is assuming you actually have  a cam lobe gone - which doesn't sound likely...

Lack of ZDDP additives are NOT going to cause the cam to go flat in ten minutes. The only thing that causes immediate cam failure is improper break-in. I believe that the aftermarket companies are using such fast ramps for even hydraulic flat tappets (in the quest for the most horsepower bragging rights) that it had significantly increased camshaft failures and they (the manufacturers) needed a place blame... The faster ramps made the break-in procedure even more important and the engine more 'picky' of proper break-in.

All that being said, I think you're probably over-reacting as not changing the oil is not absolutely going to cause a failure - you need to have a more definitive reason to believe this first...  

Your oil circulating through your motor goes through you oil filter, however some of that oil get slung of the crank called windage which is how the cam get its lubrication during brake in! & you wont know until you pull the oil pan or intake if there is any damage? But if your oil pressure is still just as high as when you first fired it up ? i would put some oil additive like lucas oil or any with zinc,& phos, additives! These will ensure better brake in !  

I am going to have to pull the intake and get a better idea whats going on.  I did see a lot of metal in the oil when I changed it, so I was thinking that the lobes may have been rounded, but could simply be the engine wearing in. One more thing, I did not prime the pump either, before the initial startup. The tapping is what mostly got me thinking about this being the cause. It could be a lifter not pumping up and I am hoping that I am over reacting. It would not be the first time, that's for sure.  

Not priming the engine isn't a very good idea.  

I know, just a step I forgot, been awhile since I have installed a rebuilt motor in anything.  

I was told today that since I did not prime the engine I did what is called a cold start and could have screwed up a rod bearing. This is the knock I am told that I am hearing. Now what if this is so?    

hi, in 1981 chevy and oldsmobile got lifters mixed up at shipping,sending deisle lifters to chevy.these ground down the cams as they where harder matierial made for the olds D,olds lifters were ground down in exchange,they were to soft for the big D engines.fixed many myself !cam and lifter should match hardnes factors or you'll have your result.MVM