|Gauge, oil line, solder nipple and union nut|
My latest purchase is this original Ariel oil pressure gauge, of exactly the right type for the Square Four. This is connected into the double oil line above the cylinder head with a short pipe that comes down through a tube welded into the fuel tank.
You can just see it in the top of this picture. The short line is made from parts from Draganfly - 17" of 1/8" copper tube, two 1/8" solder nipples and appropriate 1/8" BSPP union nuts. You can see the conical nose to the nipple, and the conical seat in the gauge - together these form a metal to metal seal. The nipple is soft soldered to the tube using Baker's Fluid, lead solder and a small blow torch.
That 2 BA stud on the back of the gauge passes through a welded bracket in the petrol tank.