Hot Bolts and Galvanic Corrosion

[Ameer Antar]

I agree w/ you totally. The only one near the turbo I don't think are that great are the lock nuts used on the front pipe to turbo outlet. The studs are fine, but the nuts aren't in good shape at all. The 4 of them will cost like $36 at the dealer, so I'm probly gonna try SS nuts and lock washers (lock nuts can't handle the heat). So what type of SS are you using? I'm planning on using 18-8 SS on the cool areas, but 316 on hot spots. The 316 is supposed to be much stronger at high temps than 18-8 and others like 304. 

Also I was thinking of seeing if anyone would want to start a small nut/bolt group buy for people doing an engine rebuild. I guess I will float this idea again this weekend in a separate email..just seeing if there is any interest...

-Ameer

---Original Message---
Date: Thu, 27 Nov 2003 10:53:21 -0800 (PST)
From: Jim Green <jeg1976 at yahoo.com>
Subject: Re: Hot Bolts and Galvanic Corrosion
To: quattro at inspirinium.com
Cc: Quattro list <quattro at audifans.com>
Message-ID: <20031127185321.2069.qmail at web20009.mail.yahoo.com>
Content-Type: text/plain; charset=us-ascii


--- 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

__________________________________
Do you Yahoo!?
Free Pop-Up Blocker - Get it now
http://companion.yahoo.com/


------------------------------