wessco,

I cannot answer your question, I only did research in the past for the backplate mounted needle valve on an OS Max. because I did have (main) ballbearing problems and I did hear other people did have also.
That was why I did ask if the threadstarter also did use a "backplate mounted needle valve".
It would be interesting to see a picture of that engine set-up.
See how effective the "crankcase" ventilation is in the engine room of the "Cookbook?".

BTW
After a hight temp quit, the heat (+200 C ?!?) of all the head-, piston- , lining- and exhaust metal is divided over the metal of the crankcase also, that already can have a temp of 100 degrees. A simple calculation gives and total engine temperature of 166 degrees C. High enough to "exchange the ball bearing".
Only ventilation of the crankcase will lower the end temp of maybe 166 degrees.



Someone else can answer the question?

Cees