The ubiquitous Series Land Rover engine block an ideal candidate to demonstrate fitting cup-type core plugs. To get this garage door opener parts craftsman of plug out, using a suitable punch, tap the plugon one side and it should spin around on itsaxis. Two minutes with the invaluable digital vernier and I discovered that 75mm is in fact 762in, which is 12 thou
012in over 75in. It doesnt sound a lot, even in metric 3mm , but it means they are too big to fit the hole! Once the blue air had cleared, how do you trim off the said 12 thou and keep the thing concentric? After a bit of head garage door opener parts craftsman I devised a plan; I decided that the only way was to turn them down on the lathe, as they needed to be round so as to seal against the hole and recess. But this posed another question how do you grip a small dished plate so that you can turn the edge down? After some more head scratching I found a piece of 1/in diameter tube and a piece of bar.
I machined the solid bar to fit the revolving centre in the tailstock of the lathe and roughly to the contour of the outside of the Welch plug. The tube was placed in the chuck and trued up and the edges smoothed; I then cut a piece of cork gasket and smeared it with RT V on one side so that it would stick to the bar in the tailstock. I clamped it overnight in the lathe with a Welch plug fitted to mould the cork to shape. I set the Welch plug to run as near true with a Dial Test Indicator and tightened the garage door opener parts craftsman Taking very light cuts and a sharp tool I soon had a Welch plug of the right diameter, and while the lathe was set up I machined another seven to complete this engine.