Case over filling with oil after rebuild
 

After a complete 2.7 rebuild, new oil pump, seals, pistons, cleaned oil tank ect. We are experienced oil accumulating in the the case to the extent that it over flowed into bell housing and saturated the cloth disc,

The motor ran perfectly during the first hour of operation. Prior to re-spliting the case we checked the hard old return oil line and the seals leaving the case for obstructions. After the case was split the oil pump was inspected and appears to be in as new condition.

What could cause this condition? Hard to believe the oil pump is bad as it was brand new and worked during initial road test. The oil tank was thoroughly cleaned, the oil filter was inspected ect.


Any ideas would be greatly appreciated, thank you guys for your time and knowledge.

Once running all the oil in the engine is scavenged out. Unless you knocked the "O" ring off the scavenge side of the pump then you would have no flow out to the filter line or at least a lot less..
11 quarts of oil and you're soaking the clutch disc....
Bruce

The o rings were checked first and present.

Just a thought, if the intake/sump pipe for the oil pump came loose or broke, it wouldn't be able to scavenge. If a different pump or a different sump cover combination caused interference with the sump pipe, maybe that could break off the sump pipe or crack the epoxy holding the pipe in the pump leading to a delayed failure.

Is it filling the case after you shut it down and it sits or is this happening while it is running?

Same ting happening to a friend years ago.
He had left a paper towel, probably in an oil return tube, and that clogged up the oil pickup.
Doesnt seem to be your issue, but could the oil pickup sit to close to the sump plate (If you have one) ?

The case was split and the pump was inspected, checked out, no broken parts or obvious signs of damage.

We thought about the clearance between the pump and the slump plate as a possible issue and double check the updated oil pump part number.

Yes fills while running
Struggling to find the answer

Are you sure the case is filling or is it just a bad rear main seal? How much oil did you drain out of the case?

oil in case
 

Did you update the pressure relief valves and springs?Maybe you mixed them up.Fred

Sounds a lot like a restriction on the return side somewhere.

What is your oil pressure when the engine is running? Have you checked the level in the tank while it is running?
If it ran for an hour I would think the high pressure side is getting enough oil to keep it lubricated, but not scavenging enough oil. Scavenge side has no restrictions until the oil filter. I would check the relief valves and springs as faapgar suggested.
http://forums.pelicanparts.com/911-engine-rebuilding-forum/712724-ultimate-oil-pressure-relief-valve-thread.html

Hate to ask, but was the case recently modified for the standard oil pressure relief modification? Somebody forget to install the plug?