Oil Pressure Frustration

In Bubba;s post he posted about making sure the 3 oil return holes, "oil drain back holes" are clear and full sized, they are located between the lifters, to drain oil to the pan. But you skipped over it . Also if the rod oil spurt hole is facing the cam it will throw more oil up to the lifter valley "lifter galley" it goes the other way,but the oil spurt hole will not cause your problem alone.

Blow by looked higher than what it should be but I could be wrong.

It is not the cam bearings. The front cam bearing has a small groove in it to lube the cam retainer if it was wrong it would be a minor amount of oil ,still below lifters . 2 and 3 have one hole ,if they were off no oil would get to the journal and burn up , the last bearing has a slot that oils up to the rocker shaft and you know it is working. The bearing are each a different size and the cam wont fit so they have to be in the right order. But I guess any thing is possible.
 
I had a similar problem after my rebuild. Oil press was dropping very low after motor warmed up especially at stop lights. Low enough to kill my oil press controlled electric fuel pump. Upon inspection i was getting oil push out the distributor hole and around the dip stick hole. It seemed that too much pressure wasnt letting oil drain back down to the pan.

My solution was to ditch the synthetic for heavier weight oil. I ditched the pvc system completly and run 2 small filtered push jn breather caps in the valve cover and run a cold air intake style air filter from classic inlines.

The result was normalized internal pressure, no more oil being pushed out the block and rock steady oil pressure. No problems since these changes.

You guys are alot more knowledgeable than i am as far as too the why, but these are simple things to try if you havent already.

Good luck!!
 
Early into this problem I checked for oil accumulating in the distributor. Many years ago I had strange internal pressures, oil warning light coming on (this was before I installed the oil pressure gauge), actually had exhaust coming out of the oil fill tube and significant oil in the distributor. Turned out to be a piston with both compression rings broken, which I discovered by its extremely low compression. New piston and rings for the affected cylinder fixed it, though it was just a temporary patch-up until I could do the rebuild. I have had nothing of that sort happen here.

I also changed to a heavier weight oil, 10w40 conventional, with no effect at all.

I am going to have a closer look at the block though (lifter gallery). I saw nothing unusual when last I had the head off (July), and did remove and examine the lifters, but since the excess oil is definitely coming from the gallery it warrants another look.
 
To drag200stang,

Thank you for the explanation of the cam bearings, I don't remember taking a good look at them, though I did know that they are each a different size. I didn't install them so just didn't notice any details about them. This means that don't (yet) need to remove the camshaft (and consequently, entire engine) to see what's up down there. Trying to avoid that.
 
Another thing that I know for a fact that will contribute to the drain back issue ,is cold thick oil. Is the water- oil getting up to at least 180 f with a real gauge ? I know you said the engine was hot ,just wondering if it is really up to temp.

It could be a lot of things adding up or one big thing ,can not wait to know what it is.
 
I have an oil-temperature gauge. At an all-Ford swap meet I found a guy who sold reproduction cast aluminum Rally-Pac housings. Housing only, add your own gauges. Did the tachometer, but didn't need a clock, so I installed an oil temp gauge. Mounted the sensor into the oil pan.

When I first added this gauge the temperature went way hotter than I expected, at a sustained highway speed it sometimes went off the scale (gauge reads 250 at maximum). I then replaced the 195 thermostat with a 180. The maximum the oil now goes is about 215-220. The oil pressure fluctuation usually does not begin until about 195. I have never seen it happen below 180.
 
I just started a new post because my issue is slightly different than yours but just about as frustrating. At 4000 rpm I lose all oil pressure! this just happened and so I parked it and let it sit to drain oil back down if that was it. Just started it and zero pressure. Also my top end does make noise under these circumstances so I might rule out too much oil in my top end. Seems to me it has to be the damn pump but it sure primed up with a drill and ran great up to about 2500. I will say that I have had two consecutive brand new amc oil pumps stick closed and blow up the oil filters so I know sometimes things defy the odds. One thing, I did drill out the rockers as the manual suggested on the new adjustables I got to the diameter of the stock 78 rockers. I realllllly hate to pull this motor!
 
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