I Remember working on stags years ago they notorious for water problems, the worst thing was the head gaskets. You have to take all the head stud’s out of the block before you can get the head off not easy at all. Your bolt is quite easy,you should try tapping the end with a hammer drill out the middle with easy outs should come out,plenty of heat and shocking the bolt needs hitting harder and sharp blows .
good grief , thats as easy as stud removal ever gets ,,, 1 your using the wrong part of the torch flame 2 cut a hole in a bit of plate and let the stud stick through , then heat it , not warm it , 3 let it cool and oil it , repeat twice , third time try turning the stud out with the vise grips ,,, failing that a drop of weld from a stick welder would get the heat up , its simply not warm enough.the heat and cool cycle expands the stud then relaxes it , this breaks the rust down , all it takes is practice and patience.
Jiggle pin should be at the top of the stat, not down the bottom. 🙂 I have never had the Thermostat housing bolts snap off (or even be tight) and have a few inlet manifolds here, the ridiculous head studs are the worst ones for that. As far as stat housing, on mine I don't have the hot air intake duct (pointless here, it doesn't get cold enough), so I have had (for 30 years) a Ford small block V8 stat housing, as it allows the use of a straight (Gates) hose that is very common here. Keep it simple. Early on I also put helicoils into all 12 of the inlet manifold bolts mating threads in the heads. As the manifold lines up, it often puts side loading on the threads, and soft alloy easy to strip or damage. ALWAYS the last one. Wheras SS helicoils make them impossible to damage/far better piece of mind/ a lot more secure. I have stripped half a dozen Stag engines, (and always maintained mine) and mine initially (31 years ago, I bought mine Feb 1993) took a week with injecting penetrene etc down the sides of the head studs, let it sit/lock nuts to get them out. None snapped off luckily. They are a ridiculous idea, they have a ridiculously optimistic "screwdriver slot" in the end which is only good for assembly. There are various locking tools, but if they are stuck, none work. There are jigs for hydraulic jacks that pull the heads off over the studs etc etc etc. The usual "get heavy with them" is to weld nuts on, then get them off, but they can snap. I had to cut one as it was stuck for good, but that head was corroded beyond usable, just wanted the block and the fittings from the head. The second my studs were out, I never used them ever again. I went and bought high tensile socket head (allen) bolts, $5 each in 1993. Best 50 bucks I ever spent. In the 31 years and 330,000 km since, the socket head bolts ALWAYS come out easily, it just isn't an issue. The factory should have done that. Why keep the head studs when they CAN be a problem (usually ARE), when you can use headed bolts that NEVER are??? I would never put a torch anywhere near an assembled engine like that. That open flame near flammable stuff around it............ not a good idea to me. What I WOULD have tried was to stick arc welder earth to manifold, tap my arc welder electrode on the end of the stud and have it tac to it............. get very hot - disconnect the earth strap. If that didn't loosen it, then I would remove the inlet manifold. Put the stud into my enormous Dawn bench vise, and then just "unscrew the manifold from the stud". I have never known that to fail with things of that size. Maybe try that "stud in the vice" before you go to the "shop" seeing you have the manifold out anyway. Good luck.
I have never had a Stag dist stick. But I had one seize into the block on a Ford V8 (351C). Common problem, as there is a well/lowest point such that any stat housing leak pools in the dist well. Mine was stuck fast. I had to cut off the top of the dist, then chisel the shaft surround such that it broke in half then pulled out. If I dropped ANY part of it - engine strip. I was lucky enough to remove it with NO debris dropping down. Phew. Probably suck eggs, but with the Stag one, I would seep penetrene into it for as long as you can, then some gentle persuasion. On mine I used to play with the timing all the time, as our cars here were smog spec, so vac RETARD (yuk) so played with it a bit to get away from that. I have never had the coil next to the dist, it makes it to hard to access, my coil is over behind the LH strut tower. That also allows visual inspection for coolant and oil leaks in the valley. I used to do a LOT of miles in mine (drive home across Oz for Xmas leave and back every year for 7 years) so access and being able to see what was going on was essential. Good luck mate.
You should have avoided the drill, and put more heat on the casing, then quench with cold water. Reapply the heat then try again with the mole grips. If that doesn't work, weld a nut to the stud with a mig welder. The heat from the mig and a bit of torque should move it. Reassemble using stainless studs with copper grease. Not bolts.
You need to heat the bolt - not the housing. And heat it to read hot. It's expansion is what will free it. Welding a nut on also heats the bolt. Using a center punch on a broken bolt does not usually give you a central hole. Use a die grinder tool in a Dremel (or similar) to give a good central landing spot for your drill. Easy to fine tune. The size extractor you were trying to use would just have broken off if it had actually threaded. If you can get a central small drill through the bolt then drill with largest size that does not destroy threads. And go right through the bolt - this weakens the hold. Will then extract easily - with the bigger extractor. Make sure you have a good quality extractor set - cheap ones are not even good as paper weights.
