We look at fitting the water temperature gauge and heater matrix pipes but before we could do this we needed to get some new unions in order to fit them.

The problem we had with the water temperature gauge was that the original part that came with the coolant temp gauge (the silver adapter in the picture) was to small for the thread in the inlet manifold which was 5/8 BST (British Standard pipe Thread). Mark asked his mate with a lathe if he could help and he kindly made us up a brass union with the correct thread that now fits the manifold 1/2inch NPT (National Pipe Thread). He did this using 1″ hex brass rod then tapped a 1/2 NPT thread on one side and for the other side they measured the diameter of the original union which was 0.650 diameter x 19TPI (threads per inch). He then used this measurement to screw cut the thread on the lathe.

The other union we needed was for the heater matrix outlet pipe to connect to the inlet manifold. He made this to match the 16mm stainless steel pipe that we had for the heater matrix pipes. He then tapped a 3/8 NPT thread to the end to enable it to be screwed in the the manifold. While we were at it we got him to make some stainless steel olives to be braised to the heater matrix pipes.