Junglie Posted March 11, 2023 Share Posted March 11, 2023 Shock, horror...reassembly is starting! I don't really want to re-use the remaining exhaust bolts having had the stubs of a couple extracted from my cylinder heads, so any recommendations for studs to put on the V8? Or just any generic ones are fine? Cheers. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted March 11, 2023 Share Posted March 11, 2023 Generic ones are fine, worth looking on ebay or similar for a kit with long brass nuts -prevents corrosion.... Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 11, 2023 Share Posted March 11, 2023 Think I got mine from MiniSpares - 3/8 UNC on the head end, 3/8 UNF on the manifold end plus brass nuts (if memory serves). You may need to knock 1/2" off the UNF end to make it easier to fit the manifold in-situ without disturbing the studs. Quote Link to comment Share on other sites More sharing options...
Junglie Posted March 11, 2023 Author Share Posted March 11, 2023 Thanks chaps. The engine is out so at least I don't have access issues at the moment. Now discovering that the previous owner's approach to oil leaks appeared to be "Do it up until the bolt nearly snaps...and then a little more" so I now have to get one of the oil pump bolts extracted. Not sure how one gets that much torque on an 8mm bolt without it breaking. Ah yes - one doesn't... Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 12, 2023 Share Posted March 12, 2023 Ah - the old "torque it until it goes loose then back off half a turn" 2 Quote Link to comment Share on other sites More sharing options...
Junglie Posted March 12, 2023 Author Share Posted March 12, 2023 I have to laugh otherwise I'll set fire to it... Sodding stud extractor has snapped off in it so I can't even drill the bugger out. Sense of humour is being tested today. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 12, 2023 Share Posted March 12, 2023 Can you post a pic of which one you've bust? At the very least we can commiserate with you over it but someone might have a solution. Quote Link to comment Share on other sites More sharing options...
smallfry Posted March 12, 2023 Share Posted March 12, 2023 Might have been glued in with bearing lock or similar because the thread was stripped, or corroded in place by the dreaded multi metal syndrome. Presume you mean those stupid "easyout" left hand thread tapered tap things ? I have never, ever, managed to get a broken bolt out with them, and I think it is because they are tapered, and actually open up the broken bolt or stud in its hole, jamming it even more effectively. I have seen some that are splined, but you have to hammer these in, so I suspect the outcome would be the same. However, I use a sacrificial torx bit instead, after drilling as big as I dare. As regards your problem now, lets see a photo ? Quote Link to comment Share on other sites More sharing options...
Junglie Posted March 12, 2023 Author Share Posted March 12, 2023 Sure. This is how I left it. The actual extractor (and yes, it's an eze-out)is pretty much dead centre, so of course I've ended up drilling next to it because the bloody thing is so hard... Options occuring to me are cut the whole thing out and replace it with JB Weld, then drill and tap that, or even just drill and use a nut on the top; do the same but weld it (riskier perhaps as the heat might distort it) or the Rolls Royce option of spark erosion. But I'm happy to hear any suggestions... Quote Link to comment Share on other sites More sharing options...
hurbie Posted March 12, 2023 Share Posted March 12, 2023 i would weld some blobs on the remains of the extractor and try to get it out ...then you can drill the remains of the bolt out . other option is weld trough a m8 steel ring and build the weld up (or weld a m8 nut onto the ring (from the inside)) so you can grip it with grip-plyers , or a spanner. Quote Link to comment Share on other sites More sharing options...
Stellaghost Posted March 12, 2023 Share Posted March 12, 2023 22 minutes ago, Junglie said: Sure. This is how I left it. The actual extractor (and yes, it's an eze-out)is pretty much dead centre, so of course I've ended up drilling next to it because the bloody thing is so hard... Options occuring to me are cut the whole thing out and replace it with JB Weld, then drill and tap that, or even just drill and use a nut on the top; do the same but weld it (riskier perhaps as the heat might distort it) or the Rolls Royce option of spark erosion. But I'm happy to hear any suggestions... If you can get at it from behind, drill from the back and then knock the ezi-out out, then drill the bolt out leaving a thin skin behind which you should be able to collapse inwards with a sharp punch, you could also make a masonry drill slightly sharper, add a bit of oil and drill through the ezi-out, it will do it but slow and steady Regards Stephen 1 Quote Link to comment Share on other sites More sharing options...
Stellaghost Posted March 12, 2023 Share Posted March 12, 2023 11 minutes ago, hurbie said: i would weld some blobs on the remains of the extractor and try to get it out ...then you can drill the remains of the bolt out . other option is weld trough a m8 steel ring and build the weld up (or weld a m8 nut onto the ring (from the inside)) so you can grip it with grip-plyers , or a spanner. This will work also Regards Stephen Quote Link to comment Share on other sites More sharing options...
hurbie Posted March 12, 2023 Share Posted March 12, 2023 8 minutes ago, Stellaghost said: drill the bolt out leaving a thin skin behind which you should be able to collapse inwards with a sharp punch this is my normal procedure for broken bolts 🙂 Quote Link to comment Share on other sites More sharing options...
elbekko Posted March 12, 2023 Share Posted March 12, 2023 Worst case find a friendly machinist that can line it up properly in a mill and drill it out. 1 Quote Link to comment Share on other sites More sharing options...
Junglie Posted March 12, 2023 Author Share Posted March 12, 2023 All good ideas, definitely worth a look. I hadn't thought about a masonry drill. That's a great idea... Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted March 12, 2023 Share Posted March 12, 2023 Welding the aluminium unlikely to go well, it is an old casting well impregnated with oil.... A nut and weld to the difficult-out and it should come free. These timing covers are expensive, so worth taking your time and saving it if you can. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 13, 2023 Share Posted March 13, 2023 I've seen mention on machining forums of using a chemical to dissolve snapped taps without harming aluminium parts, could be worth a google. I would not weld that if I could avoid it, it's a small tab so the heat will build up and by now there's not a lot of steel showing to weld to. I'd worry about damaging the aluminium further. Going in from the back with a left-handed drill bit might be an option, although bolting it firmly to a milling machine and having at it is the nicest option if you can find someone to do it. Quote Link to comment Share on other sites More sharing options...
Junglie Posted March 13, 2023 Author Share Posted March 13, 2023 My cousin's technique is to sit a nut on top of the stud and then fill it with weld. He reckons the heat normally does the trick and releases the stud anyway, but doing it with the nut there keeps it all neat. Ish I can't get to the back properly because of the shape of the case. I think spark erosion may be my safest bet, but I really want to try to do it myself. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 13, 2023 Share Posted March 13, 2023 1 hour ago, Junglie said: I think spark erosion may be my safest bet, but I really want to try to do it myself. There's plenty of DIY spark erosion setups on YouTube, not a 5 minute setup but they're out there... Quote Link to comment Share on other sites More sharing options...
Gazzar Posted March 13, 2023 Share Posted March 13, 2023 Potassium aluminium sulfate? Alum? Nitric acid? Sulphuric acid and electric? Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted March 13, 2023 Share Posted March 13, 2023 Milk and two sugars? I can't remember but there may well be multiple recipes from the various old hands on machinist / mechanic forums. 1 Quote Link to comment Share on other sites More sharing options...
Junglie Posted March 14, 2023 Author Share Posted March 14, 2023 A technique that used to work on old Japanese motorbikes with cheese-head screws on engine cases was to put a drop or two of Caustic Soda at the base of the screw head - capillary action took it down the thread and ate the corrosion locking the screw in. Then it was a case of flushing the hole with vinegar followed by fresh water and drying it before the caustic ate the cases as well... Never considered needing it on here until it was too late. 1 Quote Link to comment Share on other sites More sharing options...
steve b Posted March 14, 2023 Share Posted March 14, 2023 Take it to an Engine machine shop and have it removed and a helicoil fitted. Steve Quote Link to comment Share on other sites More sharing options...
Junglie Posted March 14, 2023 Author Share Posted March 14, 2023 15 minutes ago, steve b said: Take it to an Engine machine shop and have it removed and a helicoil fitted. Steve Yeah, I think that's going to be only option. Quote Link to comment Share on other sites More sharing options...
steve b Posted March 14, 2023 Share Posted March 14, 2023 (edited) Top tip for future stuck/tight bolts like this is if it doesn't move with normal force give it a good sharp tap with a steel hammer onto a brass drift rod on the head of the bolt . This is often enough where potential corrosion has bonded it in. Steve Edited March 14, 2023 by steve b 1 Quote Link to comment Share on other sites More sharing options...
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