New TC78 smokes on deceleration
As far as the oiling I would personally go with a bigger drain line and make sure you have good ventilation. I drilled a 3/8 or 1/2" hole in the valve cover cap and screwed in a plumbing 90 degree fitting and a hose to a catch can just to be safe.
That's a start it might not fix your problem but it's not money wasted, the problem with the stock ventilation on a motor is it's designed to work when the engine see's vacuum and under boost or no vacuum it stops venting which is when we need it the most.

So let me summarize and correct me if I'm wrong or forgot smth.
1) bigger drain. I couldn't realistically go bigger than 5/8" ID, and outlet from bearings is smaller than that
2) improper crankcase ventilation - how do I check that?
3) busted valve seals - how do I check that?
4) scavenge pump - hmm... a bit more complicated than I would like to...
Didn't quite understand that about engine stop venting...
So please give me your suggestions on these points
2. What do you currently have for crankcase ventilation? Stock config or something you've created?
3. Valve seals would smoke on decel whether you'd been in boost or not. The vacuum pulls the oil down the guides into the cylinders. Have you pulled your plugs to see if any are more grimy than others?
4. Scavenge? Is this a rear mount?

So let me summarize and correct me if I'm wrong or forgot smth.
1) bigger drain. I couldn't realistically go bigger than 5/8" ID, and outlet from bearings is smaller than that
2) improper crankcase ventilation - how do I check that?
3) busted valve seals - how do I check that?
4) scavenge pump - hmm... a bit more complicated than I would like to...
Didn't quite understand that about engine stop venting...
So please give me your suggestions on these points
Stock ventilation. Should I upgrade it?
I saw this only after turbo installation, that's why I'm not very sure about valve seals...
I didn't pull them after turbo. Before they all were similar
No, it's front, but among suggestions there was also to install separate pump
I really have no vision now what to do/check next... except maybe trying to squeeze the feed line a bit and see what happens (although it's within TC recommendations, 6mm or -4AN)
No hills anywhere near unfortunately... Any other way to check if drain is insufficient? The Best V8 Stories One Small Block at Time
I'll research about venting, if that is really necessary when putting turbo?
mightyquickz28, I asked about restrictor in the very first post. I think I'll ask DrTurbo directly. Although in instructions it doesn't mention restrictor, only dictates line size: -3AN or -4AN







