Head gasket

[edthecat]

I bought my car, 75 sports, with no compression on no1, made the bold assumption it was a burnt exhaust valve. On getting the head off, I was pleased to find it was a holed valve. I replaced that and another which was cupped, and had the other 4 refaced. The little man from the engineering company even came out offering to recut the seats, but when he inspected them, he said it wasn't necessary. So I got it all together again, and it started fine. A pressure test read 90 to 99psi. However, on a run out negotiating a hairpin bend, something made the engine produce an awful whirring sound, along with a misfire. A pal said did I retorque the head, er no, not yet. Another pressure test revealed 46psi on no 1, so I retorqued the head and the whirring noise disappeared and all has been fine for a few months. However, power is down and water regurgates from the radiator, pressures now around 70psi on all cylinders, and, its running hot. Head gasket?