Colin ..... my racer uses Triumph GT6 discs ..... but they're 'skimmed' from 13mm thick to 7mm .... brake man was slightly taken aback to be asked to do that ... and at the bags of swarf chippings that came off .... then once they're drilled they're suitably light 🙂 .... his machine skims both faces simultaneously, which he claims is the way to go for trueness.
When I lived in the States I was talking to an old engine guy who reckoned that the V8 blocks that Chevy used on their racers were left in the yard to rust as bare castings for a year .... then pulled in and machined ... all to de-stress the castings for maximum strength.
K
