Hot Bolts and Galvanic Corrosion

[Jim Green]

--- Timmmy <quattro at inspirinium.com> wrote:
> Allright here's a question for you all.
> 
> Rebuilding my engine, I am using as many stainless
> socket head bolts as
> possible, most of which are relatively cool and low
> stress. but what
> happens if I replace some of the "hot bolts"
> starting with the coolest
> ones - the inlet manifold bolts, then moving onto
> the exhaust manifold
> studs, and finally the worst case...turbo to
> manifold, and turbo to
> downpipe.
> 
> I am concerned about Bolts welding in due to
> Galvanic corrosion, or worse
> the Al in the head corroding away, or the iron in
> the block.


Timmy, SS is fine, but for anything around the turbo,
stick with what the factory had there.  I'm not sure
what the studs on the EM and turbo are made out of,
but I haven't been able to find anything that comes
close to resisting corrosion like they do.  I'm using
through bolts on my header, and have tried all kinds
of grades and alloys, only to have them all rust out
on me.  Currently I'm using 10mm SS bolts with copper
nuts for the turbo to header connection, and factory
hardware for the turbo to DP connection.  I don't have
many miles on the SS bolts, so I can't say how they
will last.  Anyone have any better ideas?  Titanium?

=====
Jim Green
'89 80q slow
'89 90tq fast, really fast
http://www.mswanson.com/~jgreen/car_home.html

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