I have a 71 F250 with an FE 390 no mods. Engine is a 3 year old rebuild with around 20k miles. I started noticing a clack sound coming from the passenger side of the engine. I pulled the valve cover and the rockers are bone dry. I have good oil pressure and the driver side is pumping oil like crazy. I removed the rocker arm assembly, pulled the plugs and turned it over to check if any oil would come through the oil port. None, not a drop.
I keep finding conflicting information over what to do next. Some say it is a spun cam bearing blocking the oil port and the engine needs a tear down. Others say on the FE a spun cam bearing doesn't block oil to the head.
Any suggestions/insights or guidance on what I should do or where the problem lies?
As you can see in the pic, the passenger side oil supply is further back the main (center) gallery:
It does look like it may have something to do with the #4 cam bearing, but you are correct....it has a groove machined in the block, so cam bearing wear shouldn't totally stop the oil flow. A spun bearing should have no effect. Now if the cam bearing totally slipped fwd or aft, I can see a problem.
It's a weird problem and probably means an engine tear down. You might want to start by removing the passenger side head and doing your cranking test, but it's unlikely anything will change.
Oh....you say there are no mods, ....are you sure? If there are oil restrictors, that one may be plugged. Look down the angled hole on the rocker stand boss that supplies the oil.
Wish I could help more, but that's very weird and I can't envision the problem other than a bearing shifted fwd or aft, and I wouldn't think that is a very common problem.
The FEs require that the bolts with the an under cut be installed so the oil will flow to the rocker shafts and rockers. They can be seen in the oil flow submitted by Argess. If the incorrect bolt is installed in the oil passage hole, NO OIL flow.
You removed the rocker arm shaft. Did you check the oil passages top and bottom in the shaft making sure their not blocked with crud? I've disassembled mine completly and used my air compressor to blow them out. A pipe cleaner works good too. Also check the little oil holes in the rockers.