Oil in air box

SOURCE: oil in air box

Yep, its somewhat normal. Your crankcase ventilation tube connects to the back of the airbox. There is a small foam to dampen the airflow and remove the droplets from the flow - but other than that the crankcase is connected to the airbox. Now the good question is that what amount is normal, i.e. under what conditions there may be excessive amounts of oil generating so much positive pressure to crankcase that the oil becomes clearly visible in airbox... one reason may be too high oil level to start with ? Other reasons may relate to some kind of piston blowby - like rings glued into the piston? Also it is sometimes possible that PAIR lets air to move back to the airbox - but have not seen that happening in a busa, just in a car. In that case rather than oil its black carbon residue which feels a bit oil'ish. You can test the crancase pressure by removing the hose from the back of the airbox and feel the pressure when engine is running. It should not be blowing air out - but some pressure, or more like pulses will be felt. (Its so long time when I have last done this test, so maybe someone could describe this better...) Anyway this reminded me about the fact that in cars there is often a PCV valve, positive crankcase ventilation valve. I am just wondering why we dont have that in busa ? The performance related desire to have negative crankcase pressure surely is not the reason...