Bunny,
When you say your engine suffer quite badly from wet sumping, what are the symptoms? Have you drained the crankcase to see how much oil is actually in the sump before startup? With a clear vent line, I would think it normal to see a certain amount oil moving one direction or the other once the engine starts, but it may be just a few ounces, which in a 3/8" vent line could look like a lot.
In normal operation with a healthy engine, there will inevitably be many ounces (like maybe 1/2 to 1 quart/liter) of oil in the crankcase after only a few hours of shutdown due to all of the residual oil in the engine draining down to the lowest point, plus any of the hot, thin oil back flow through the oil pump into sump. Dry sump engines are never truly dry, only relatively so when compared to a wet sump engine.
If you are not pumping oil into your intake manifold and/or out the air cleaner on startup and the engine's not leaking when standing idle for a few days, then I would say there is nothing to worry about.
There is probably at least 2 Litres of oil in the sump and now I have a clear vent line I can track its progress! As you can see it is up above the steering rack now.
![[Linked Image]](https://tm-img.com/images/2021/04/04/Wet_Sumping_compressed.jpg)
The engine has been standing for around a week without running. Fortunately the crank seals seem to be good and I'm not getting any leaks from the engine (front or back).
This is quite a high volume of oil to shift back to the tank so I think I'll adopt the manual drain method for the time being.
