Are these nuts acceptable to use as exhaust nuts. They are normally used for intakes. They are made of brass. They have a thinner wall than normal for extra clearance. I know the copper nuts are the standard however would these work?

Why?

The Cap'n

2 reasons

-I have found that certain headers leave very little clearance for the socket to go over the nut. I had this problem with KH headers.

-I have a bunch of these in my garage and I don't have any of the copper nuts

They aren't as strong as steel nuts, so if you're using them to "pull" the flange in to seal they might not hold. They're also dissimilar metals, so you could get some galvanic corrosion, but probably no more than you'd get with steel nuts. Other than that I don't know why not. If it were mine I'd go ahead and give them a try. What's the worst that could happen?

Copper nuts are not really copper nuts...they are copper coated steel.

I think brass would be a bit soft for exhaust nuts.

You can get 11mm X8mm nuts. V8 Audi's use them and other sources.

If you get galvanic corrosion with copper or brass against steel because they're dissimilar metals, why would you think you'd have that problem with steel on steel? I don't follow your reasoning.

The Cap'n

There are also the steel 8x12mm nuts found on Porsches since the 1950s.

The Cap'n

Sorry not clear, point was that you might get galvanic corrosion from the dissimilar metals, but you get heat/ferric corrosion from regular steel on steel anyway, so no particular disadvantage.

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The problem is the expansion difference in the metals will tend to make them loosen up more than if both the stud and the nut and the washer had the same coefficients of linear thermal expansion.

you'll find you might need to use a thin walled 1/4 drive socket/extension to squeeze in there. in most instances the 3/8 drive ones are too fat. mind your torque values.

k

Brass nuts are a common alternative in the VW world, but pretty much one-time use because the metal's soft. Here, some rocket science: 10mm Flanged Exhaust/Intake Nuts

I have used them without issue but you will want to get a sturdy washer under them depending on which heat exchanger you are using. They are narrow enoungh and soft enough to work into the exchanger without a strong enough washer. Few things a like about them, not the least of which is that I can get them at my local AC VW shop. Dont have to deal with the socket getting pinched, and I actually like the fact that they are a softer metal as well because you are more likely to damage the nut if you overtighten them rather then the stud or the head. Pick up an extra set and double nut them for insurance.

I have seen one place online that made this same size in steel but dont remember where that was.

Whatever you do just dont use those coper plated lock nuts unless you fell like punishing yourself down the road!

These look pretty sweet.

Why not use the 911 exhaust nuts? They are an internal drive steel nut so you can put enough torque on them. I'm skeptical that you can put enough torque on the brass nuts to give you adequate clamp load to prevent exhaust leaks. Another option for tight clearanc eoptions would be a 12 point drive nut like what ARP sells.

David