Whats the reason for the sealing washer that goes in next to the timing side main bearing? Meaning, why does it need sealing, and from what? Why not just let the head oil return through the bearing into the crank case? My reason for asking is that my Maney cases have no holes from timing chest to crank case. I’ll be running a cNw / Comnoz breather on the back of the case. I am about to drill the ‘Comnoz oil return hole’ just below the pump and got to wondering why not just allow oil to return through the bearing? I’m pretty sure there’s a sound reason for this that I’ve overlooked... can someone please enlighten me?