RB25 , its deffo crankcase gasses because i did solve this problem by fitting a catch can and re routing the breathers but it restricted the breathing and crankcase pressure increased causing oil leaks etc so i compromised by fitting the catch can in lineESL wrote:Interesting. Is that on an RB20? It may also be caused by transitional det on lift. If you can access the sites the engine will visit on lift off (transitioning from high to load loads at high rpm) and pull some timing out that may help.
Pulling timing out does helps but thats because the engine is making less power , working less hard and producing less crankcase gasses