robertwheeler Posted January 20, 2006 Share Posted January 20, 2006 Hey there In a week or 2 this car will be mine My brother decided (against my advice) to try and tap the bolt holes on the exhaust manifolds for slightly larger bolts.... I told him the threads still felt good.. but the bolts shake loose.... try thread lock (hi temp)... instead he destroyed the threads. My Brother says there seems to be an extra set of bolt holes on the manifold.. at least on the driver side... I havent had a chance to follow this up yet... but is there a backup set of bolt holes on this manifold? Thanks Robert Quote Link to comment Share on other sites More sharing options...
rllywgn Posted January 20, 2006 Share Posted January 20, 2006 i believe he's right. if i remember correctly you can spin the flange and have it rewelded. but i dont think the extra set is tapped. Quote Link to comment Share on other sites More sharing options...
Vanislru Posted January 20, 2006 Share Posted January 20, 2006 The 2nd set of holes is tapped. Quote Link to comment Share on other sites More sharing options...
robertwheeler Posted January 20, 2006 Author Share Posted January 20, 2006 It would be great if the threads are intact... but I would be happy even if I had to tap it myself. The nice thing about the spare bolt holes.... I can make sure the threads are OK and all that.... and I don't think I need to drop the flange that's on there now at all... until i'm ready at least. Lets assume the threads are good.... and I use thread lock... It seems these just come lose again.... Seems this would be a great place to convert to stud's and if I had an ark welder these could be neatly tacked on... Ive seen how fast that gasket blows out if its loose... the after market manufacturer's gasket is pretty bad... is the original any better? Thanks Robert Quote Link to comment Share on other sites More sharing options...
robertwheeler Posted January 23, 2006 Author Share Posted January 23, 2006 Drat. I guess I wasnt thinking.... the flange is a solid pipe.... so it would need to be cut and then welded.... anyone ever use helicoil on these? Robert Quote Link to comment Share on other sites More sharing options...
swervey87gl Posted January 23, 2006 Share Posted January 23, 2006 One set is for the turbo manifold and the seccond is for the non turbo. You have to cut and reweld your manifold. Just use Mig its easiest. Quote Link to comment Share on other sites More sharing options...
swervey87gl Posted January 23, 2006 Share Posted January 23, 2006 I take that back The pipes are double wall. If you cut it you won't be able to reweld the inside pipe. I would try to retap the holes that are all screwed up. Maybe drill and retap. Just a thought. Quote Link to comment Share on other sites More sharing options...
85Sub4WD Posted January 23, 2006 Share Posted January 23, 2006 I use OEM gaskets almost exclusively, because the aftermarkets always seem to fail - I have gotten good service out of OEM ones, NAPA gaskets are probably your best alternative First thing I would do is make sure I have a grade 8 or higher stud - preferably grade 10 - I have never had much problem with these seals before - you are using metric studs aren't you??? (sorry if it seems like a stupid question, but I have seen it happen - people don't realize Japanese car = metric bolts) unless he drilled them, you can probably (believe it or not) still salvage the threads - just make sure you use PLENTY of the cutting oil, and move the tap back-and-forth every so often (keep it clean) - aluminium is great for problems like this because it is so soft Quote Link to comment Share on other sites More sharing options...
idosubaru Posted January 23, 2006 Share Posted January 23, 2006 anyone ever use helicoil on these? no but i've helicoiled plenty of other bolts holes. works great and not hard at all. might need a right angle drill to get to some holes. if you have easy access, definitely go this route as it's not difficult at all. Quote Link to comment Share on other sites More sharing options...
robertwheeler Posted January 23, 2006 Author Share Posted January 23, 2006 Hi Just a small silly question here..... is there a donut for this flange? He is using aftermarket gaskets and they keep blowing out.... A missing donut would explain this. Thanks for your comments Robert Quote Link to comment Share on other sites More sharing options...
Subaru Jim Maple Ridge Posted January 24, 2006 Share Posted January 24, 2006 You can retap the holes to 7/16" NC, use 1" common bolts c/w vibration washers, preferrably internal, along with Walker 31309 gaskets. You don't need to pre-drill and a bottoming machine tap is required to cut threads all the way to the bottom. This can be done without taking off the pipe, as long as you fill the flukes of the tap with grease to trap the cuttings. It also helps to make sure that the old gasket is all out. Quote Link to comment Share on other sites More sharing options...
robertwheeler Posted January 29, 2006 Author Share Posted January 29, 2006 Does anyone know the specifications for the original bolts? Thanks Robert Quote Link to comment Share on other sites More sharing options...
85Sub4WD Posted January 30, 2006 Share Posted January 30, 2006 the original bolts are M10, 1.25 pitch - I'd go with class 8 or better steel I found a gasket from napa intended for the EA81 that seems to work better than the stock ones - I can get you the part # later good luck Quote Link to comment Share on other sites More sharing options...
robertwheeler Posted January 30, 2006 Author Share Posted January 30, 2006 the original bolts areM10, 1.25 pitch - I'd go with class 8 or better steel I found a gasket from napa intended for the EA81 that seems to work better than the stock ones - I can get you the part # later good luck That would be great. Im thinking there might be a way to use the 2 extra holes to add some strength to the original bolts.... maybe i can get a universal flange and put it over and fit it to those bolts or maybe some big fender washers... I think I will eventualy try to tapp these things out the right way.. but its too cold these days... and no garage Robert Quote Link to comment Share on other sites More sharing options...
robertwheeler Posted February 7, 2006 Author Share Posted February 7, 2006 You were right about the gasket. I examined very closely the new but failed gasket and the gasket that Napa offers. The material in both is very similar but the Napa gasket is just a hair thicker and there is a metal seal around the inner part of the gasket.... to give it strength. The Other Gasket didn't have this last part and was just too weak and very unforgiving of thread problems. I went out to buy some new bolts as per the Specifications mentioned on this thread a few posts back..... and I made a somewhat Unusual discovery. My Brother when he tried to tap these bolt holes forgot to take into account the depth of the original threads and when he tried to tap it... he used a smaller tap then the original threads and I think it has left most of the original thread intact... if not 100% perfect... still there. He ended up chasing the threads but with an SAE Tap I got this car over the weekend and registered it today. It needs a bit of work but Its quite drivable... with a bit of care. Needs 3 tires.... rear brakes and rotors.. and of course the exhaust work... and I think I have a handle on that.... in no small part with help from here Robert Quote Link to comment Share on other sites More sharing options...
robertwheeler Posted February 8, 2006 Author Share Posted February 8, 2006 These bolts are proving to be hard to find... lots of m10's but only with coarser threads.... 1.50 , I may be forced to order these from my Local Subaru dealer... But I'm still looking. Robert Quote Link to comment Share on other sites More sharing options...
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