Sean73 Posted July 18, 2005 Share Posted July 18, 2005 Long story short, I have a broken thread tap in one of the injector hold-down holes on my N42 intake manifold. I tried drilling it out with a cobalt bit, but it doesn't even touch it. It's lodged in there real good. Should I just throw this manifold in the garbage, or is there something I can try? Quote Link to comment Share on other sites More sharing options...
BillZ260 Posted July 18, 2005 Share Posted July 18, 2005 You need a CARBIDE endmill or a tap burning machine. Take it to a machine shop and let them work on it. W/ a tap burner it'll be easy but depending on where you are, the local machine shop may not have one. Good luck. What size is the tap? Tiny I am guessing... Quote Link to comment Share on other sites More sharing options...
shauno Posted July 18, 2005 Share Posted July 18, 2005 There is a new tool out now (well, new to me anyway) that slides down around the broken tap and engages on the cutting flutes of the tap. You just slide it in and unscrew the broken tap. One thing I don't know is whether they come that small. good luck. Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted July 18, 2005 Share Posted July 18, 2005 Stop by any local auto dealer and get the name of the Snap-On or Matco supply guy. Anyone in the service shop will be able to help you. Both companies sell tap extractors. Once you've got the tool the extraction should be easy. If you've damaged the hole trying to remove the tap it may be a bit more difficult. I've used snap ring pliers on either side of the tap to twist it back out with success too. Heat the manifold with a torch (propane) at little too if you have to. The aluminum will expand faster than the steel to help loosen things. Quote Link to comment Share on other sites More sharing options...
Here comes trouble Posted July 19, 2005 Share Posted July 19, 2005 With small broken taps..my luck has been to break them in pieces with a chisel or punch and remove the pieces with hopes the damage to the hole will allow salvage with a bigger tap and larger threads.... a new intake manifold may be a lot less problem... a broken tap is usually lodged in there very tight giving to the reason for breakage in the first place. Try all the suggestions above but do not let your costs overun a replacement manifold. Quote Link to comment Share on other sites More sharing options...
Sean73 Posted July 19, 2005 Author Share Posted July 19, 2005 Thanks for the ideas. Has anyone ever tried heating the tap with a torch, and then shock-freezing it with some refrigerant? Hopefully the tap would shatter on it's own without damaging the surrounding material. I already located a replacement manifold, I just hate to throw a N42 intake out. Quote Link to comment Share on other sites More sharing options...
mom'sZ Posted July 19, 2005 Share Posted July 19, 2005 Sean: Hung around a motorcycle machine shop and saw a lot of broken hardware embedded in cast aluminum pieces, a real problem. Taps are super hard, a titanium bit is the only thing that will touch it. If you go that route, center punch it so the bit doesn't migrate to the softer aluminum. But in a similar situation I saw the bolt boss get ground off (along with the busted tap) and aluminum material added with the welder and redrilled and tapped. It could maybe save the manifold. Quote Link to comment Share on other sites More sharing options...
2126 Posted July 19, 2005 Share Posted July 19, 2005 Maybe a little expensive........EDM will certainly do the job! Quote Link to comment Share on other sites More sharing options...
Here comes trouble Posted July 20, 2005 Share Posted July 20, 2005 I like the shock freezing idea...try to localize it to the tap. Probably no need to heat. Quote Link to comment Share on other sites More sharing options...
Clifton Posted July 20, 2005 Share Posted July 20, 2005 I would just leave it and use the one bolt. The injectors are all connected to the rail. You could be missing half of the bolts and it wouldn't go anywere. Quote Link to comment Share on other sites More sharing options...
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