Just a quick update this one. There was talk on the WSCC forum about the oil return possibly being too low and so submerged in oil. This would cause pressure to increase in the oil return which in turn could well force oil through the seals of the turbo. When I first drilled the hole I was sure I was well above the oil line, but I hadn’t put any science to it so I could have made a mistake. I did a bit more searching today and the most stringent of all suggests is to drill with a centre no lower than 2″ from the sealing flange. Good news, I was well within that.

I refitted the dipstick and looking down the sump you can also tell that I’m some way above the normal oil line.

Some of the internet pages on the subject suggests going too high will put you in conflict with the oil pickup pipe. This was more of a worry than the height of the hole. I thought I was far enough forward but of course the pipe goes from the back to the front of the engine. I quickly removed the pickup pipe and windage tray and dropped them into the sump:

Whoops! Ah well, luckily a long way from the pickup pipe so I modified the windage tray slightly.

As has been present through these photos the nut for the back of the fitting arrived today. This isn’t to hold it in place, it’s just for another opportunity to seal the hole to stop any oil leaks. I put some threadlock on the threads and sealant on the flange of the nut then did it up. Hopefully this will do the trick.