911 914-6 Oil scavenge issue

[kc4ssd]

OK please bear with me as this will involve some info...

On the downstroke of a 914-6 buildout. I had a 80 911 3.0l as a donor car. It was my daily for some 10yr and just beat it up. Upon dismantle had 136k miles and the internals inside the engine looked great for the beating it took. I have it in the 914 now and it has a scavenge issue that when the external oil tstat opens to the front cooler it does not keep up. The engine crankcase is filling with oil where it pushes the oil out the breather back into the OEM 914-6 oil tank. I verified this by putting a 3/4in clear pvc inline to see the oil forceably moving to tank. I can hear labor on engine as it is about to happen and I also feel heat up front at oil cooler. I disconnected my oil cooler lines to the front and used air at very low pressure (maybe 2-3psi) to check to see if I had a restriction going up front. When the engine is cold it is not an issue. The oil flowed through the front circuit with ease. I was worried I had one pinched between the fuel tank. I routed my lines up the driver side rocker, up to the front compartment, behind fuel tank, through sheet metal to front trunk oil cooler. All #12 AN SS. I then removed both of my reliefs, measured and double check all is correct. I am now worried that my oil lines to the front may have too much elevation?? They are about dash board high, could this be my issue? I would think the scavenge should overcome this. It is not any higher than they were in the 911 wheel compartments. I never had any issues with oil in the 911. I have reviewed my pics and did not miss any seals for case to pump. What am I overlooking here. Here is a link to my build pics. Not in time order but lots of pics to see my plumbing.

Tim Naples FL

https://goo.gl/photos/9LDBUmAeFohwkycT8

[Jdub]

Smarter posters will reply, but to be clear the thermostat is absolutely opening cleanly and fully at the correct temp.? Oil cooler was flushed, lines are known to be clear as well? That is, this is not an obstruction issue, but a push issue.

Not sure if this delves into the "anti-cav" bowler-style oil screen, required location of the drain bolt (driver-side), and updated pressure springs set done around '78. That is about all I have on this. Good luck!

[kc4ssd]

Answers as follows, everything in the oil circuit is new. All new T stat, new #12 lines and fittings and new setrab cooler. I personally assembled everything and then assemebled and blew air through to make sure there was no hose debis etc. The engine is a 1980 and has the updated springs etc, and verified both are in the right spots when I had my 1st overspill. The T stat actually is a pas through with a port that closes between the 2 straight through ports. You can see right through it open or closed. It just bypasses when cold.

Thanks to all helping with this one!