Exhaust manifold studs Q

[jdbubb@ix.netcom.com (Dan Bubb)]

You may be forced to find a machine shop that has an EDM. (electrical
discharge machining) Basically, an electric arc in an oil bath that erodes
the metal.
Dan
----- Original Message -----
From: Marc scirocco Québec <marc_scirocco@yahoo.ca>
To: <scirocco-l@scirocco.org>
Sent: Saturday, June 22, 2002 11:11 PM
Subject: RE: Exhaust manifold studs Q


> I have a brand new cobalt drill bits set. I tried a
> smaller size, 1/8. Nothing, hardly any metal came off
> after over one hour of drilling. I tried different
> bits, nothing.
>
> Cheers.
>
> Marc
>
>  --- Peter <peter@thescirocco.com> a écrit : >
> -----Original Message-----
> > From: scirocco-l-admin@scirocco.org
> > [mailto:scirocco-l-admin@scirocco.org] On Behalf Of
> > Marc scirocco Québec
> > Sent: Saturday, June 22, 2002 10:00 PM
> > To: Peter
> > Cc: scirocco-l@scirocco.org
> > Subject: RE: Exhaust manifold studs Q
> >
> >
> > Heli-coils went in for two of the holes. Now the
> > last
> > son of a b***h looks like it is a stainless steel
> > stud.
> >
> > Titanium drill bits did nothing. Cobalt drill bits
> > with four points did nothing. Lots of cutting oil,
> > low
> > speed (+-200RPM), high pressure, and I am down into
> > the stud about 1/16 of an inch.
> >
> > Any ideas? A machine shop?
> >
> > Cheers.
> >
> > Marc
> > '83 Scirocco
> > '88 Scirocco Slegato
> >
> > Stainless isn't any harder than the stock hardened
> > studs...
> >
> > I'd try a new drill bit first...
> > Sometimes they loose their edge before you can get
> > them all drilled out.
> >
> > Pete
> >
> >
> >  --- Peter <peter@thescirocco.com> a écrit : >
> > >
> > > -----Original Message-----
> > > From: scirocco-l-admin@scirocco.org
> > > [mailto:scirocco-l-admin@scirocco.org] On Behalf
> > Of Marc scirocco
> > > Québec
> > > Sent: Sunday, June 16, 2002 8:46 PM
> > > To: scirocco-l@scirocco.org
> > > Subject: Exhaust manifold studs Q
> > >
> > >
> > > Here it is, I am about to install this 4-2 exhaust
> > > manifold.
> > >
> > > Now, 3 of the old studs are out, no problem. The 3
> > > remaining studs broke, with nothing to grab them.
> > >
> > > I drilled 2, one of them is gone now, but the
> > > threads
> > > are shot... And I am sur that it will be the same
> > > thing for the remaining 2 studs.
> > >
> > > At this stage, I do not care if the new studs ever
> > > come out again, so I am thinking about drilling a
> > > hole, and welding/gluing the remaining 3 new
> > studs,
> > > JB
> > > weld, or something similar...
> > >
> > > Anybody has done something similar in the past?
> > Any suggestion?
> > >
> > > Cheers.
> > >
> > > Marc
> > > '83 Scirocco
> > > '88 Scirocco Slegato
> > >
> > > Using 8mm x 1.25 Heli-coils is how I would fix it.
> > > The kit comes with a tap for the steel coil
> > threads,
> > > you drill the
> > > 21/64" hole, run the tap through, the key to
> > tapping
> > > cast iron is back
> > > and forth, back and forth, in very small steps,
> > you
> > > thread in the thread
> > > coil and you are done.
> > >
> > > The tough part is drilling the hole in the center
> > of
> > > the broken stud.
> > > A small 1/8" pilot hole in the center of the
> > broken
> > > stud is a good start
> > > and a drill press doesn't hurt.
> > >
> > > Peter
> > >
> >
> >
> __________________________________________________________
> > Lèche-vitrine ou lèche-écran ?
> > magasinage.yahoo.ca
> >
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> >
> >
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