trebor69 Posted September 1, 2013 Share Posted September 1, 2013 As above really, think I may have stripped the threads one one or two of the studs (threads in the head actually) with having to keep taking this bloody manifold/1st decat off and on to mould it around the column ....PITA ....fits now but the damage is done .....wish I'd have known this before I bought it . I hear there is a repair stud (slightly oversized thread , head end) but where from? Can anybody help please ? Quote Link to comment Share on other sites More sharing options...
Al Massey Posted September 1, 2013 Share Posted September 1, 2013 The studs can come out mate, just get some new ones or at a push some 2nd ones. Quote Link to comment Share on other sites More sharing options...
Guest Roger NE Posted September 1, 2013 Share Posted September 1, 2013 (edited) No just trying to replace the studs with new ones is a waste of time once the thread in the head has stripped The BEST way of repairing them is to use some special Exhaust Studs that a UK company had made . . . They have the correct original thread (10mm and fine) on the manifold side (so it is just like new) . . . but on the head side it's an 11mm thread. Because of that you don't even need to drill or anything . . . just run the correct size Tap into the hole, then screw the special Studs in and it's a permanent proper fix (best use some Loctite) I think this is a much better repair than Helicoiling the hole (as some people do) . . . . and a lot less work That's probably what you're thinking of . . . . . I did 4 of mine with them about 3 years ago I'll try and find where I bought them . . . even harder was finding the correct size Tap at a reasonable price ! Edited September 1, 2013 by Roger NE (see edit history) Quote Link to comment Share on other sites More sharing options...
Guest Roger NE Posted September 1, 2013 Share Posted September 1, 2013 They're made by Fensport . . . never found them on their Website, but they knew what I meant as soon as I phoned The Tap you will need is an M11 x 1.25 Quote Link to comment Share on other sites More sharing options...
trebor69 Posted September 1, 2013 Author Share Posted September 1, 2013 They're made by Fensport . . . never found them on their Website, but they knew what I meant as soon as I phoned The Tap you will need is an M11 x 1.25 Thanks pal, that's exactly what I need Quote Link to comment Share on other sites More sharing options...
trebor69 Posted September 1, 2013 Author Share Posted September 1, 2013 (edited) The studs can come out mate, just get some new ones or at a push some 2nd ones. Yes I know mate, had to take them out a few times with this manifold as clearance isn't great but I now think the stud is pulling out of the head as I thighten the nut on to it .....am going to check it with my vernier caliper as I thighten it (checking stud end distance from head etc) before I try oversize. Edited September 1, 2013 by trebor69 (see edit history) Quote Link to comment Share on other sites More sharing options...
David P Posted September 1, 2013 Share Posted September 1, 2013 I've recently had similar issues, this may be of interest to you. http://www.mkivsupra.net/vbb/showthread.php?233707-Project-Supracharger&p=3680412&viewfull=1#post3680412 Quote Link to comment Share on other sites More sharing options...
trebor69 Posted September 1, 2013 Author Share Posted September 1, 2013 I've recently had similar issues, this may be of interest to you. http://www.mkivsupra.net/vbb/showthread.php?233707-Project-Supracharger&p=3680412&viewfull=1#post3680412 Heavy duty dude , didn't think you could go up to M12 but I guess I was wrong Quote Link to comment Share on other sites More sharing options...
Rich.2211 Posted September 1, 2013 Share Posted September 1, 2013 I 'V Coiled' mine and it seems spot on. Torqued up perfectly. Requires drilling and tapping to M12x1.25 first though by which time you could just use a repair stud. Quote Link to comment Share on other sites More sharing options...
David P Posted September 1, 2013 Share Posted September 1, 2013 Heavy duty dude Heavier duty here. http://www.mkivsupra.net/vbb/showthread.php?233707-Project-Supracharger&p=3711501&viewfull=1#post3711501 Quote Link to comment Share on other sites More sharing options...
trebor69 Posted September 1, 2013 Author Share Posted September 1, 2013 Heavier duty here. http://www.mkivsupra.net/vbb/showthread.php?233707-Project-Supracharger&p=3711501&viewfull=1#post3711501 Ha, yes I've already seen what you did to that manifold and I applaud your vision, faith and commitment.....I have fabricated some things in my time but you sir have my respect Quote Link to comment Share on other sites More sharing options...
David P Posted September 1, 2013 Share Posted September 1, 2013 Just brute determination, thank you. Do you have a thread about what it is your up to? Quote Link to comment Share on other sites More sharing options...
trebor69 Posted September 1, 2013 Author Share Posted September 1, 2013 Just brute determination, thank you. Do you have a thread about what it is your up to? No I don't David, just gradually going through the car bit by bit, most recently I bought an N/A manifold and 1st decat what later turned out to be a LHD manifold/decat which supposedly fitted with 10mm clearance to the column (my arse) and after numerous off's and on's with varying amounts of heat and persuasion I managed to get it fitted properly and clear of the column but have lost heart in it (now it finally fits) and have fitted a whifbitz 1st decat to my standard manifold and only now whilst fitting this set up do two of the studs decide they are not happy ....hence the search for repair bolts Quote Link to comment Share on other sites More sharing options...
David P Posted September 1, 2013 Share Posted September 1, 2013 Those 11mm studs sound to be your easiest way out. Quote Link to comment Share on other sites More sharing options...
Guest Roger NE Posted September 2, 2013 Share Posted September 2, 2013 Well the beauty of them is that they are still the STOCK size on the Manifold side . . . . so it doesn't look like a repair, and you don't end up with lots of different size nuts (or threads)! It's also a quick repair, as there is no drilling required. Personally, I've always thought the reason the studs start coming out in the first place is because Toyota use Steel Nuts, which because of all the heat, rust on the thread - so when you try unscrewing them the Stud comes out, rather than removing the nut. And being an Alloy head, the thread very quickly strips. SO I have always used special Copper or Brass Exhaust Nuts, so they don't rust on. Quote Link to comment Share on other sites More sharing options...
Al Massey Posted September 2, 2013 Share Posted September 2, 2013 Yes I know mate, had to take them out a few times with this manifold as clearance isn't great but I now think the stud is pulling out of the head as I thighten the nut on to it .....am going to check it with my vernier caliper as I thighten it (checking stud end distance from head etc) before I try oversize. Ah my bad, I read it wrong Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted September 2, 2013 Share Posted September 2, 2013 Just Helicoil the stripped threads in the head. You may need to make up a jig if you aren't very accurate with an air drill. You may find you need an air drill and a stubby drill bit if access is limited. Just junk that manifold, look where it's got you now.... And when it warps and cracks you'll be taking it off yet again. Quote Link to comment Share on other sites More sharing options...
Guest Roger NE Posted September 2, 2013 Share Posted September 2, 2013 Surely using Helicoils is a far inferior repair Engineering-wise than using the specially made repair Studs? I've known people drill a larger hole and tap them for the Helicoils . . . the Helicoils then break . . and really the head is then ruined ! Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted September 2, 2013 Share Posted September 2, 2013 How can a Helicoil "break"? It's just a spiral of specially formed stainless wire. It could pull out, but break? A properly made repair in aluminium alloy using Helicoils results in a stronger thread than the original cut directly into the parent metal. Most critical aerospace threads into aluminium alloy are Helicoiled from new. As are autosport threads into aluminium and magnesium castings of a critical nature. Hewland transaxle threads are often Helicoiled due to the need for frequent disassembly causing thread wear. All early Rolls Royce engines had block threads and critical head threads Helicoiled from new. Cost cutting reduced this. A Helicoil is a wonderful device. Pity there are so many thread forms and sizes, I have quite a selection, but the tooling is quite dear. I can't imagine not having them around. There are loads of Supra TT exhaust elbows around that I resurrected from broken studs when "de-catted" thanks to Helicoils! Of course, like most things, a Helicoil can be badly or wrongly inserted, but they are pretty foolproof if you follow the instructions. http://www.newmetalworker.com/reviews/helicoilsrvu.html Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted September 2, 2013 Share Posted September 2, 2013 EDIT!! They say you can "stack" inserts. Be VERY careful, I disagree with this, it is very hard to get a smooth progression from the start of the first thread of first insert you put in, to the end thread of the next one. Finding you have got it wrong after you have snapped the tang on the 2nd or further insert can get you in real trouble, real fast. use the 2D, 3D or 4D inserts (twice, thrice and four times the depth of a stock 1 times the thread diameter insert). Need more than 4D? Something very very odd there! Quote Link to comment Share on other sites More sharing options...
Guest Roger NE Posted September 2, 2013 Share Posted September 2, 2013 I've no idea how they break, as I've never used them . . . but I know several people who HAVE had them break The point is that the studs don't need to be constantly removed . . . . once it's in, it should stay there ! (and if you use non-steel nuts, it should never be un-threaded) Personally I just think using the Repair Studs is a much more straightforward permanent repair. Also, can you get Helicoils in the correct fine thread used on the stock studs? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted September 2, 2013 Share Posted September 2, 2013 I have the kit, the drill, the inserts and new studs right by me Quote Link to comment Share on other sites More sharing options...
Guest Roger NE Posted September 2, 2013 Share Posted September 2, 2013 If you have already all the Kit, and use them a lot, I can understand why you would use that repair method But for someone who only needs to replace a couple of Studs, has never used Helicoils, has to buy all the kit, suss out exactly what to do . . . well I think using the Repair Studs is a much simpler, quicker and safer option! But that's just my opinion . . . Quote Link to comment Share on other sites More sharing options...
jay200bhp Posted September 2, 2013 Share Posted September 2, 2013 (edited) most aly threads are tapped and helicoiled on race cars when new as chris w says are far stronger than just a thread into ally... if youve broken a helicoil youve put it in wrong like an end of a bell Edited September 2, 2013 by jay200bhp (see edit history) Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted September 2, 2013 Share Posted September 2, 2013 Who are you calling a bell end then? Quote Link to comment Share on other sites More sharing options...
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