What is the curent thinking on exhaust stud nuts, Copper or regular? Options

[Demick]

When double-nutting, how the hell do you get a wrench on the top nut in order to tighten the 2nd nut against it?? I've never attempted this, but I remember barely having enough room to get a socket in place on one nut - I can't imagine trying to get a wrench in there to hold the first nut while adding a 2nd.

[PRS914-6]

Just a quick note on stainless hardware. If you use a stainless stud and a stainless nut the chances of galling and never getting them apart is very high especially when used on an exhaust system. Stainless galls REALLY easy and an anti-seize compound is a must. I have worked in the water and wastewater industry all my life where stainless is the norm and the above is what I have experienced.

[jk76.914]

There's an interesting article on stainless steel hardware (and it's appropriate uses) in last month's issue of Motor Magazine. Non-geek that I am, I dunno how to get you the pages from the PDF, so I'll give you a link. Once you have the PDF, go to page 26. Perhaps we can end this clueless insistence on the use of SS hardware. Here's the link: http://ct.emeraldmail-usa.com/rd/cts?d=7-1...25-0-0-0-1-2-23

BTW, the factory used one kind of exhaust nut on the 1.7/1.8s, and another on 2.0 cars. BOTH were steel with a SS insert. A Helicoil, or whatever brand they use in Germany. I save and reuse them as often as I can, as they work just fine unless/until they get rounded off. They are the best thing I've found to maintain the torque in the hot/cold environment of the exhaust system. I also paint the studs with anti-seize.

Maybe someone can get the contents of the article into an e-mail so we'll have it here for all to see.

The Cap'n

Heli-coil calls them "heli-nuts". They were designed for aircraft applications originally, and they are very forgiving in environments with wide extremes of temperature. The helicoil has some give to it , or spring if you prefer. It allows for some expansion and contraction with temperature. If you look into them, you'll see that the middle couple of threads are flattened, which gives some locking effect. They are advertised on Helicoil's website as reusable multiple times. I called them a while back, and found out that they aren't stocked any more. I could probably have had some made, with an minimum order of 25000 or so I guess.

My '76 2.0L was first disassembled in 2002. 7 of the 8 nuts came off without damaging the stud. The 8th one unscrewed the stud from the head. Not bad for 98000 miles and 25 years, I'd say.

Does anyone know where I can get 6 of these????

Jim

[Rand]

When double-nutting, how the hell do you get a wrench on the top nut in order to tighten the 2nd nut against it?? I've never attempted this, but I remember barely having enough room to get a socket in place on one nut - I can't imagine trying to get a wrench in there to hold the first nut while adding a 2nd.

You're right, a couple of the nuts are a royal pain.
Nothing like a vice, a torch, and a grinder for customizing a wrench. (IMG:style_emoticons/default/wink.gif) (bend and grind some off the sides)
Could also sacrifice a socket - cut the end off, weld a rod to the side. (IMG:style_emoticons/default/wacko.gif)

Curious what Jake does...

[Jake Raby]

Most every engine I build gets a stub pipe of some sort, these have much greater clearance around the nuts and room for a stubby snap on 12 or 13mm wrench to get on the first nut, jam againt the tube(or head) and hold that nut tight while I put a torque wrench with a socket on the bottom nut.

I also have a long 13mm wrench that I bent into a hook on the end that can be used with stock heater boxes, but I haven't used that bastard in years! probably not since the last time I actually worked under a 914 ;-)

[ConeDodger]

Most every engine I build gets a stub pipe of some sort, these have much greater clearance around the nuts and room for a stubby snap on 12 or 13mm wrench to get on the first nut, jam againt the tube(or head) and hold that nut tight while I put a torque wrench with a socket on the bottom nut.

I also have a long 13mm wrench that I bent into a hook on the end that can be used with stock heater boxes, but I haven't used that bastard in years! probably not since the last time I actually worked under a 914 ;-)

Yeh! Must be nice to not actually work on cars!!! (IMG:style_emoticons/default/biggrin.gif)