Exhaust Nuts
 

Which nuts should I be using to reinstall my headers? I've already replaced the exhaust studs but am unclear on the appropriate fasteners to use. It looks like my rebuild kit from PP came with 6 barrell nuts and 6 copper locking nuts.

This is for a 930.

Thanks,

Well, if you were using 930 heat boxes they filled the order but the items will still bolt the tubes up. Use anti seize.
Bruce

I've got a set of B&B headers that are going on.

If i'm not mistaken, don't the B&B headers include a wacky Z-shaped wrench for some of the tight access points? My former B&B headers on my '87 needed one of those wrenches, as well as a 13mm u-jointed socket. So use whatever nut goes on easiest. Plain M8 steel nuts are just fine. Some of those "copper" nuts are kind of a joke. Sure they don't seize, but they also don't lock for long.

If you can use the barrel nuts where access is tight, go for it. They work great. The key is to use a hex key that has a ball-end on it. You can cut the bend off of an L-shaped key and then insert your straight hex key into a 8mm socket.

Agreed 100% with Bruce. Use a quality antiseize. I like Never Seez because it's a thick paste that has good staying power. Regular grade is more than sufficient for our exhaust applications

Bostik Regular Grade Products - Industrial Supply Group

Some like the copper Wurth CU800 stuff. I think it's too oily and doesn't have good stiction. Usually gets pushed off the threads as you spin down the nut.

Hi There

On my 993 I used copper coated 12mm steel nuts in order to have a bit more clearance. I believe that they are used on Esprit Turbo manifolds.

Berni

What ever you decide on...make sure they are dis-similar in metal.
Steel will rust to steel...copper or brass will not.
I used stainless steel studs with brass nuts...and had to use lock washers to keep them in place.
Bob

You can get the copper nuts from VW performance shops. Even JC Whitney has them! :D

Just know that the true copper or brass nuts will round-off their flats VERY easily if you use them in places where wrench access is tight and not well-aligned with the tool! ;)

For really tight access, these M8 x 11 nuts look like the hot ticket

CB Performance - Online Catalog

Our host carries copper exhaust nuts originally for BMW I believe but they must now be popular with the 911 crowd because they also now list in the 911 section.

BMW E21 Cylinder Head & Valvetrain - Page 4

andy

I ended up going with the copper nuts. Although KTL's comment has me a little concerned.

As KTL said...they are softer than steel...but if you use the correct wrench or socket...no problems.
Just before you apply pressure on the nut to tighten it...stop for a second and consider 2 things:
1...where will your knuckes hit when the wrench slips?
2...when the wrench slips...how mad will you get for rounding off the nut?
I know that no one EVER rounds off a nut or bolt...but up here in Canada...we work in the COLD....I mean real cold...LOL...and sometimes we don't take the time to look before wrenching.
So...work slowly and carefully...rather than fast and doing it over.
Bob