[petet16]

Originally Posted by pheelay

Well, the pipe coming from the air cleaner would be clean air, right? No point trying to capture oil vapour from there. Or have I got that wrong? I guess the way it's plumbed now, there is no vapour at all being piped back into the manifold, which is good?
But if I have it right, the crank cases can't be breathing very well at all. Is that a bad thing?

We have some confusion here, the breather system allows any crankcase pressure to be routed into the intake, in the old days it was just an open pipe in the engine bay, the catch tank either needs to vent to atmosphere, or have a pipe back into the intake.