- Apr 15, 2009
Which specific PCV valve are you using?I have an 850 crankcase with PCV reed valve issuing from the rear timing side (standard position) into a small catch bottle.
I have fitted the barrel which has been lined to 750 (for racing purposes), with new Omega pistons, rings and big end shells, along with a new oil pump. The engine was rigorously cleaned including the centre of the crankshaft, before re-assembly.
Fired her up, and all ran sweet as, no oil issuing into the catch bottle.
Having got the engine warmed up, I revved it sporadically to 4500 - 5000 rpm, and when I turned round, the catch bottle was full of foam, and oil pouring out the breather hole in the bottle. I re-routed the main breather pipe after the PCV valve directly into the swirl pot oil tank, and managed to race without further issues.
The unit has an oil cooler, and I heard someone say that this can cause issues with the breather pumping oil out. It certainly was OK as an 850 with no cooler!