This engine was rebuilt about 16 months ago. shortly after the rebuild had a head gasket failure and it was taking water into the oil. It was repaired and ran fine. recently we had some low temps at night and when starting in the morning oil pressure would be at 80 PSI until it reached operating temp. then I noticed one morning that oil pressure was much lower than normal when cold, so I checked the oil and it was low. Then when I checked the water I found the oil in it. I pulled the intake and heads thinking I had another gasket failure and I didn't find anything obviously wrong in the area where the oil pressure feeds up through the block and into the rocker hold down bolt. Where else could the oil possibly be pushing into the water?

 

A crack in the block.

Water goes into the oil easily, as there is pressure in the cooling system after shutdown, and the pressurized water can go into an oil return hole via a weak or blown headgasket.

There is no pressurized oil going through the head gasket--only drain back oil via the drain back holes. So, the pressurized oil has to get into the water via a crack in the block that opens into a coolant passage. You would think some water would get into the oil, but the water pressure is at most what, 14 PSI? While the oil is 30 to 80 PSI.

Not good news, but you may have caught it before internal parts are destroyed as well.

 

Possibility, the oil galley that feeds oil to the heads and rocker arms. I've seen them crack before.
As I recall, this can be fixed by boring the galley out and pressing in a steel tube.

 

Not the quick fix I was hoping for, but it is still hopeful. Thanks for your input and after I figure out what happened I will post it.

 

I've seen it as well. You can use a pushrod from a 300 I6 or 350sbc to sleeve it with. I've also heard of people using a 1/4" roll pin. It should be press fit and sealed with Loctite. Make sure it's not too long, you don't want it making contact with the cam bearing. The time I did it there was a ridge just before you got to the bearing that worked well as a stop and measuring point. I don't know if this is present in all blocks though.

 

X2... unfortunately somewhat common with FE blocks. But, it can be a quick fix using brass stock or a spare pushrod and pressing it into the compromised oil galley feed.

Josh