15-08-2020, 10:53 AM
I have tried welding a nut onto the remains, but it didn't work. I have cut the stud short and filed down to be flush with the side of the block, after which it was possible to drill out the remains. Dot punch dead centre and work with gradually increasing size drills until you are up to tapping size. It is a good idea to put a bit of stainless steel behind where you are drilling: it will give you some warning before you drill into the cylinder wall. You may need to finish up at 3/8" thread depending on the state of your block. I use stainless steel studs, loctited in, and make the stud the right length for a dome nut on the outside. Dome nuts (ideally stainless in this situation) with a fibre washer overcome any sealing problems.