scottd
Junior Member
Posts: 76
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Post by scottd on Oct 26, 2010 16:27:19 GMT -5
Not 2 or 3, but 7 of the 8 exhaust manifold bolts broke off in the heads. (1 was already missing) There isnt enough there to weld a nut onto, and they are really corroded. I think Im going to have to drill and helicoil all 8 stud holes. I really dont want to buy new heads....any input..  |
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Post by don29163 on Oct 26, 2010 19:30:52 GMT -5
looks like the only recourse to me, drilling them is going to be tricky too. good excuse to get a better set of heads, though....
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Post by smyrnaguy on Oct 26, 2010 19:32:23 GMT -5
You might get lucky and get them out with an extractor. Drill a hole 1/3-1/2 the diameter of the stud in the center. No deeper than 5/8". Try a sturdy tapered extractor. If it works on one it should work on them all. Do not use an old fashioned threaded easy-out. They break off 100% of the time. The tapered ones with a slow twist work great and are easy to remove even if they break. Use sharp drill bits. If you're careful you won't need helicoils just new studs. Worked for me.
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scottd
Junior Member
Posts: 76
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Post by scottd on Oct 26, 2010 21:50:28 GMT -5
Im going to have to drill them all out and possibly go oversized. Every last one of em. They have become part of the heads!
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Post by leonardabell on Oct 27, 2010 9:38:56 GMT -5
I know it's a little late, but did you soak them in snake oil before you tried?
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Post by horen2tas on Oct 27, 2010 10:41:08 GMT -5
Even so, it's worth it to keep applying liquid wrench or the equivalent for a few days and maybe cook the area with a burnzamatic so its prepped for the drilling and extraction! Whatever you do take your time, you're beyond frustration now, this is a medical proceedure!!
Good luck in the O.R.!!!
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Post by jspbtown on Oct 27, 2010 19:39:14 GMT -5
Just drill them out and tap them. I often replace them with standard stainless steel studs.
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Post by thehag71 on Oct 28, 2010 4:10:18 GMT -5
Use a centerpuch on the snapped off bolts before attempting to drill. Locate it as close as you can to the center of the broken bolt. Then drill them out. Start with a small drill bit and work your way up through sizes. Don't forget some sort of a lubricant on the bits. Sometimes when you get really close to the original thread size, you can use a small metal pick to get the pieces of the bolt out of the threads,usually depends on how close you got the punch to the center in the first place. If not, drill one or two sizes larger, tap out the holes and buy bigger bolts. Or if you want to use the original size bolts, drill the hole slightly oversize, tap it, and install a helicoil into the hole. Most parts stores sell them as a kit that includes the tap also. The helicoils can be a bit pricey, but not near as much as new heads. Good luck, let us know how things work out.
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scottd
Junior Member
Posts: 76
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Post by scottd on Oct 28, 2010 5:46:03 GMT -5
I drilled and tapped all of them to the original 8x1.25 last night. Funny thing was, I thought I saw the remnants of another snapped and drilled stud. Even as I got to the final drill sizes, nothing ever budged, no metal from the screws came out. They were in there for good. The studs came out ok, maybe a MM off in a direction here and there but the exhaust manifold is a pretty forgiving part. My only concern is how the studs felt a little loose (a retapped hole never feels as tight as factory) and I had to loctite the snot out of them. We arent talking about a monster engine here, I think it will be ok...
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