I would not suggest quenching a piece of cast iron only part of which is red
hot in water. The thermal stress could break it in half. A two piece
manifold would render the re-tapping of the hole moot, however it is
probably not a cost effective way to go about it.
Rick
On 8/19/07, Blair J. Weiss <blair@ifd.mv.com> wrote:
>
> Dave,
> I've had good luck with PB Blaster... but the key is to let is soak for a
> week. Failing that, I heat up broken studs cherry red with a propane torch
> and quench it quickly with water. If you have enough of the stud sticking
> out mig weld a bold to the end and back it out... key also the heat and
> quench with some good sharp bangs with a hammer.
>
> Sounds like you are past that, having the tap hole in place. It's not too
> late to run to a hardware store and buy a non-offshore tap... don't forget
> 1/2 turn in 1/4 turn out to clean the threads.
>
> Blair
>
>
> ----- Original Message -----
> From: "Councill, David" <dcouncill@msubillings.edu>
> To: <mgs@autox.team.net>
> Sent: Sunday, August 19, 2007 12:31 PM
> Subject: [Mgs] exhaust system flange
>
>
> > Last week I removed my exhaust system. But in the process, one of the
> > studs on the exhaust manifold flange snapped. I first made a cut in the
> > remnant bolt so I could use a screw drive to remove it. Failing that, I
> > tried in EZ-out. But the bolt is securely frozen in place. Yes, I also
> > sprayed it over several days with penetrant, two kinds. Finally, I bored
> > a hole through the center of the bolt, from the initial EZ-out hole.
> > Gradually, in increased the hole up to 1/4". Now I am tapping the hole
> > again. But my carbon steel 5/16-18 tap is not making much headway. I
> > gave up for a few days and plan to resume the ordeal this afternoon.
> >
> > Any suggestions? Maybe my Harbor Freight tap is not good enough? Any
> > suggestions on a cutting oil perhaps? I should mention that I am doing
> > this under the car. I was going to pull the exhaust manifold but being a
> > bit lazy and realizing that I couldn't find a better place to hold the
> > manifold, it seemed like it was best to do it in place.
> >
> > I have a few more studs coming from Moss in a few days to complete the
> > job. Strange that the previous bolt appears to have molded itself in
> > place because it has only been maybe two years. But what is, is and
> > getting the bolt tapped is the main task at hand.
> >
> > Hopefully some of you can reply before I resume the task in about 4
> > hours.
> >
> >
> > David Councill
> > 67 BGT
> > 72 B
> > _______________________________________________
> > blair@ifd.mv.com
> >
> > Edit your replies
> >
> > Mgs@autox.team.net
> > http://autox.team.net/mailman/listinfo/mgs
> _______________________________________________
> richard.ewald@gmail.com
>
> Edit your replies
>
> Mgs@autox.team.net
> http://autox.team.net/mailman/listinfo/mgs
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