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Post-War Other Herald: thoughts on manifold flange studs and nuts

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Andrew Mace

Andrew Mace

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Time to renew the complete exhaust system on the Herald 1200. Part of that will include replacing the manifold flange studs with new ones (already busted one and expect the others to go the same way after 48+ years).

I have new studs, but I don't yet have nuts to hold the headpipe to the flange. So, two questions:

1. Any good arguments for or against using brass nuts as appear to have been original?

2. Is there any such thing as an anti-seize compound that will stand up to the relatively high temperatures of the exhaust, so that I might be able to do this again many years down the road WITHOUT busting and replacing studs?

ad - :thankyousign: - vance
 
The brass nuts might work better without anti-seize, as the soft nut would probably strip (at least partially) and maybe save the stud.

But I find that steel nuts plus copper-based anti-seize works for me. I'm still using up the last of a can of FelPro "On-n-Off" that I bought many years ago (which is apparently no longer sold),
https://cgi.ebay.com/ebaymotors/2-cans-of...4382#vi-content

However I would guess that any quality copper-based anti-seize would work about as well (Loctite and Permatex both have offerings that seem to be readily available at FLAPS). The Brits seem to like a product called Cop-a-slip (or something like that), but I've never tried it myself.

I'm pretty sure I haven't had the manifold/headpipe joint on the wrecked TR3A apart for over a decade, and it came apart easily. In fact, the only time I can recall having problems after using the On-n-Off is when the exposed threads were so corroded that the nut wouldn't easily turn over them. But since I had also used it where the studs go into the manifold, the studs just unscrewed (and got replaced).
 
:thankyousign: :thankyousign: :thankyousign:

I've still got a tube of Permatex copper-based anti-seize compound that I bought years ago when I started doing spark plugs on the Hondas and Toyotas in the family fleet; I wasn't sure whether that would hold up to the heat or not.

Any point in, say, a stainless steel nut (and washer)?
 
I like the look using brass but believe I would go with steel and anti-seize. Stainless and heat can make it gaul up on the stud. You will be replacing studs next time you have to remove manifold. If you can get the big brass nuts, you would be happy with then as well.

Marv
 
:iagree:
Stainless is problematic when exposed to heat, has even more of a tendency to gall than mild steel. There is even a special anti-seize to make it work, sorta.

Permatex says their copper AS is good to 1800F ... if your exhaust is getting that hot, then you've got worse problems than the studs!
grin.gif

https://www.permatex.com/products/automot...Lubricant_b.htm
 
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