Dad's '66 427

…. for the exhaust....

The auto parts store gave me brass nuts when I asked for nuts that bolt the exhaust to the exhaust manifold. Never did think of asking about a lock washer? I would think there should be one, is it brass as well, or some other material?

Thank you for the help!!!

856666

The brass nut is used so it won't rust on the metal stud

The lock washer doesn't have that problem and is steel (normal) material

Phil

MikeM

Brass nuts work perfectly without lock washers. Only thing, after a couple of heat/cool cycles, go back over and tighten them again.

Another tip, no batter what nut you use. Snug the nuts tight and the take a driver bat and smack the pipe collar at the manifold and drive it against the gasket. Retighten and you're good to go from now on.

Easy Rhino

Interesting. I may be out of my depth here, but many brass alloys can anneal, and therefore soften, at under 500F, and at 600F will anneal in an hour. While I doubt that your exhaust manifold studs would get anywhere close to 500F, over time they might soften. This may be why Mike's experience says to retighten them. But I would make sure that they are completely cooled down before doing so. It's true they won't freeze to carbon steel studs.

Dennisscars

This must be a new old thing, last week working on a 1960 235, was cringing to pull the exhaust manifold and deal with broken studs. The two nuts on the down pipe studs turned out to brass. To my pleasure turned loose rather nicely. Found some double thick nuts to replace them. Guess they are suppose to bugger up before the studs. Would gladly replacement them over a broken stud/manifold.

Replacing a manifold/turbo on a 1.4L today, the metric nuts over studs were brass but had enough ferrous metal to be magnetic. Must have been torque to yield or crimped as the old ones freely went back on so I bought a set of new one's that had more of a lock nut resistance.

Powershift

Use brass nuts with lock washers on OEM carbon steel studs. OR install stainless steel studs and use the OEM locking nuts. Either one will work fine and will be able to be unfastened without stud breakage.

My own 1967 car has the brass nuts with lock washers........since 1994..........no leaks yet.

Larry

Roger Walling

I never try to loosen exhaust nuts with out first heating them red hot and let them cool a bit.
I also use never seize when installing them.

I have removed the studs by heating the manifold red hot. Once when I got the stud out I noticed that the diameter had been reduced to only 1/8" in diameter because of rusting. (I must have gone to church that morning)

mashinter

I used brass nuts on my L78 and used two nuts on each stud, jamming the two together to eliminate loosening of the single nut.

Roger Walling

With all this talk about brass nuts and the fact that it has been so cold this past winter, I am afraid to look at my brass monkey in the face.