So with the Electric Water Pump conversion I need to blank the back of the pump. Previously I have put a plate from SBD over the thermostat / take off location, but this leave a big area full of static water so instead I have aimed to create a plug to fit in the back of the water pump area.

So I started with some bar billet in the lathe and made up a top hat to fit in the hole.

I then machined in a groove to take an O-ring to form a seal. I wanted to retain the bung in place so fitted an M8 thread to the centre and made up a retaining lug which would bolt into place from the inside.

The bung was then tapped into place and after adding some RTV to the threads of the bolt the retaining lug was bolted to the back to pull it in tight.

Then to finish the front inlet pipe made in the earlier post in the blog was fitted to the engine.

I guess I'll need to see how this works, but I hope it should save a bit of weight without having the thermostat void full of water. Probably the retaining lug was overkill, but I was worried that if I just RTV'd this into place that with the vacuumed formed on cooling down it might displace the bung.