Can a PCV valve be fitted so it's is fixed vertically and upright into a manifold runner? As opposed to how it is typically fitted (sideways into the inlet manifold).

I fitted one trying to address my blow-by issue and decided to plum into the runner (hole existing) to extract the rocker blow-by. I was intending to find a sidedraft carb housing to plum the crankcase vent into as the two feeds from crankcase and rocker was too much for the single PCV valve.

Anyhow when I fitted the valve it clicked a few times as the ball valve was getting knocked about with the differeing vacuum/throttle, is this becuase they don't like to be fitted facing upright or is it because the valve I have is simply old?

Any advice on addressing the carb operating issue when fitting the vent line as well (carb is essentially running lean on that runner isn't it?)?