I had this issue. Knew what the problem was as soon as I saw your title.

Re-plumbed the engine oil inlet with -20AN. Use the internal spring to prevent the hose from collapsing. No turns or bends in the hose. Mine goes right between the passenger's feet and under the seat! Got the parts from McKinney dragster. They use twin -20 pipes for fuel!

I am sure there are contributors to this site that actually possess formal and applied training in one or more of the subjects that are broached. The rest or us including myself are just guessing. To know what fluids and vapors do in a confined space at different temperatures and pressures. is black magic knowledge. What I learned from spending time on a flow bench was that there were few absolutes in what would abet flow and what would impede it and all of that would change if you altered the package. I have B''' motor up and running and with a muffler and tag, am testing it up and down I 20. I realize that will not replicate the stresses of the track, but will have to suffice for now until our test facility is complete. I made numerous revisions, the most significant I believe is moving the oil tank from in front of the wheel to behind the wheel. I also went from -12 to -16 oil line. The complete oil system dry took 18 qrts to register half way between the dots on the dip stick at 160*. I have to think my main problem was too little oil. I also think to supply the engine properly, a tank forward of the engine should have the capacity for more than 12 qrts. The more forward, the more oil needed. I think braking is a problem with a forward tank, and extra head pressure in the tank will help ameliorate starvation on the pressure side. Again, I am guessing. Will post as more information becomes available. Bob

Update! a combination of interstate testing, a full weekend at Road Atlanta and a 2 day driving school at Roebling Road, hammered it good, shifting at 7200, engine never missed a beat. Magnets are clean and oil filter elements show not one sintila of glitter. Me thinks that demon has been exorcised. Many thanks for all of your input, the many well developed subject specific and otherwise. Looking for places to go play now

Update
 

Thanks for the update, glad to see the new engine build is working out. This should help other builders avoid expensive mistakes.

What transmission (‘78, I assume a 915) are you running and what modifications and gearing do you have?

Has the transmission been reliable?

Hey Bob, glad to hear you sorted that monster. Now, get to the track and enjoy.

Nice - glad you got it sorted.

You're much faster than I am. I'm still rebuilding my 911 a year later!

G450X, it is a euro 915. I say Euro because it has the cooler on the side. I don't think I have ever seen a cooler trans that was not a Euro. I went through it 4-5 years ago, I have 12-14 events on it. I used the bearings that were in it as they looked good. I did machine and press in a sleeve to fix a loose pinion head bearing race and a year ago I installed 3-5 with shorter gears. It isn't the beast that is a G50, but still a sturdy box. I am thinking that the majority of the vintage 3.0 911s are running that box. I think the cooler on my trans is more for the ring and pinion which is good but I at some point will configure a spray bar for the gears that sit above the juice

stowsnsen914. Looking back, this was a 2 year grind. I realized after the Road Atlanta Walter Mitty (my first race in 35 years) in 2018 that I needed more motor if I was gong to be close to competitive.
I began a new motor at that time and didn't complete it until April the following year. I blew motors from June of that year until Oct of the following year. It's absurd to take so long to figure it out, but there were other circumstances that muddied the water. Throw in my lack of experience and knowledge in building motors for a car that will be tracked and a bent to the quirky or experimental, and the curve can be brutal. I have no doubt that there are other Beizels out there to deal with, but for now, I am looking for the next event and believe that I have a sound mill in the back of my car finally.

Thank you Henry, I appreciate your taking my calls and your willing counsel. My best to your pups and another virus free day. Bob