I have also had this problem after fitting throttle bodies to my j4s. It's still running vvt. When held at high rpm the catch tank filled and pumped several litres of oil out. At the time I only had the breather from the end of the inlet cam to a tee down to the sump and up to the catch tank, I then opened the blanked hole on the top of the exhaust cam cover and sent that to the catch tank as well which improved it slightly but not much. The next thing I tried was to drill holes in my new inlet manifold to open up the original holes between the ports, I sent these down to a separate tank I made which I mounted under the inlet with the a pipe in the bottom going back to the sump, also I put a pipe from the top of it up to my breather catch tank.
This seemed to fix the problem until I got back to service after a stage and found the catch tank full again. The problem is definitely a lot better as if I had done that before I wouldn't have even made it to the end of the stage before it pumped all the oil out the engine, what I plan to do next is increase the diameter of all the breather pipes and add a drain from the bottom of the catch tank back to the sump but unfortunately I'm not going to know if it's worked until the next time I rally it because it isn't doing it until it's worked very hard which I can't re-create on the road.
Edited by gingieboi, 09 May 2017 - 05:49 AM.