Hello,
I am having a problem with exhaust leaks, I am, for the first time using copper nuts as opposed to the steel with insert and flange Porsche part # 039.256.297 see photo below.

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I would still be using these if I hadn't lost one, and Porsche says these are NLA.
The procedure I would use, after replacing the copper seals, I would use Never Seez on the studs and torque the steel nuts to 16 ft-lbs.

I am not sure if I should use Never Seez with the copper nuts and I am not sure the torque is correct for these fasteners, as they are oval shaped and seem tighter to start with?

Any experience with this would be very helpful.
Thanks,
Mike

I believe the Porsche nuts are copper plated, not pure copper.
If that is a pure copper nut I would recommend not using it and using a regular one for now, or stainless.

Copper is used so it can be cold chiseled off if they are stripped or siezed- or so I was told by my favorite VW shop. They are pretty much SOP for exhaust nuts. I would only torque to 9 or 10 ft lbs- thats enough if all is clean and aligned. Studs pull out like baby teeth after all these years of heat cycling. I really F'd a head after I took my exhaust off too many time getting all obsessed with a little noise.

Make sure you get the old copper sealing rings out of the head. They get stuck in there. I use a little Aluminum duct tape around the sides of the exhaust pipes to hold the copper rings in place for reassembly.

Hello Scott,
I use a dab of gel super glue to hold the copper rings in place while bolting the exhaust together.
Thanks,
Mike

Hey I used gasket cement, but superglue is good too, and the nuts from PP and AA are fine. They are copper coated, 12mm, and work every time. They are all copper plated. I broke off some and they were OEM and not fully copper. Too soft.

Copper does do well with copper paste antiseize compound on the threads and I do torque to 11 lbs.

Buy a whole set from PP or AA, add all new copper gaskets and exhaust manifold gaskets, and nuts/bolts for them too 13mm X 12mm. I even replaced the studs into the head with 8mm X 8mm from AA.

Worth every penny to do it all, and spend the time so you DON'T burn a valve. I did once, and it was a huge bill to fix, even by myself in 1980.

John

Copper coated. You can get them from NAPA for about $0.45 each.

i'd still go with the specified torque as pointed out the self locking nut will cuase more fritction so the torque down on the nut will be a bit less than what the torque wrench indicates (however the torque on the stud will still read right so dont over compensate ) to helpo reduce the friction effect of the nut, be sure you sue plenty of antiseieze this will help lube and give you closer to the real torque value.

be sure to anneal the copper gaskets heat red hot on a stove top then allow to slow air ccol, this will soften them and allow thenm to deform adn seal easy.

have fun

Hey thanks realred914, so just to clarify, the copper gaskets are not quenched in water after heating?

I agree with Dave (realred). It would be well for everyone to remember that the original Porsche exhaust nuts, both the style used on the 1.7/1.8 cars, and the one specifically for the 2.0 cars, are NOT lock nuts, and were cad plated. All were heli-coiled. Any discussion involving the copper plated lock nuts should take into consideration they're NOT the same. They require different torque on installation because you have to overcome the locking force. The plating changes the effort, as well. I use a little anti-seize on any exhaust fastener, giving it just a little extra torque to compensate for the lessening of the friction.

If I can reuse the original nuts, or dig into the stash of used ones, I do.

The Cap'n

I can say I had fewer problems when I switched to 2.0L fastener.

Thanks for your input Cap, seems I, like politics, am one nut short of a quorum!

Nickel antisieze is for high temperature. Solid brass nuts have been used forever on chev's to keep from twisting the studs off. They can be used here also and will save the heads from the torque applied from the locking nuts you are using.

Didn't someone reccomend heating the copper gaskets up with a torch and letting them cool to soften them?

yes by all means, flame the new copper gaskets till red hot and let cool. Use new copper nuts, as they use a 12mm socket to put them in because the clearance is so tight in the exhaust area. i use anti-seize paste to "glue" the copper gaskets onto to the head.

It appears I may have a spare one. Since you may not be here for the open house at my shop and GPR (foolish move, that!), maybe someone can pick it up for you. Free will donations accepted. Where are you located?

Hello Cap,
I am in the Burbank area, I would have been there for the open house but I have to work this weekend. If anyone heads south of Burbank, I am right off the 5 fwy, at the Sunland/Vineland exit.
Mike

I had it with the copper plated nuts, and pulling the studs out of the heads.

I now double nut with 13 mm stainless nuts with SS washers.

Have not had any problems with pulling studs ever since....

Also use Milk of Magnesia as anti-seize.

I heat the copper gasket until glowing red and cool quickly with cold water, this annealing process is supposed to makes the cooper more malleable so it seals better.

Well I f*ucked it up, broke a stud trying to remove one of the copper nuts!

Any suggestions as to how I can remove the broken stud with the engine in the car?

OK I tried to remove the stud but broke it flush with the head, tried to drill it out, made a very big hole!

Never gonna use those copper nuts (or whatever they are) again!

Oh man, sorry.

you could try to tap and install a step stud, but I think you may be on the way to pulling the head for repair. Let us know how it goes.

I'll get it to Pasadena within a few days. PM me your phone number so the guy can call you. It's my ONLY spare, I'm keeping one full set on hand.

The Cap'n

I got it to work by using a 10mm x 1.25 helicoil and than inserting a 8mm x 1.25 helicoil, not very parallel with the other stud but it works!

Here is a photo of the nuts, all of the copper nuts were loose except for the one that broke the stud. I included a stainless steel bolt that I had to grind off because it galled after a week on the car.

A. copper nuts, one broken stud. Nuts had more resistance going on than the torque necessary to compress the copper gaskets.

B. Stainless steel bolt and nut used for attachment of heat exchanger to muffler, galled and locked solid.

C. A copper covered split lock nut I have used in the past and was not happy with.

D. original 1.7 exhaust nut with helicoil (38 years old)


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The copper gaskets I took out look almost untouched, I am sure I could use 3 of them again!