Lesson Hard Learned:

[Tinster]

This post from Bill is for sure worth repeating since
it looks like several folks are going to be installing
refurbished carbs. Lesson Photo attached-
I am crying in my coffee cup!! Bill wrote:

"Dale,
One thing is don't use brass nuts . These are commonly used on exhaust flanges because the brass seems to break away from the iron studs when needed after lots of heat and rust over time. Brass nuts are thick because they are brass and not that strong. Use only high quality steel nuts of the same grade as the studs. The studs that come with the head of the TR6 are just so long, certainly not long enough to hold a thick brass nut, and lock washer. Juat like putting a tire on the car, you tend to torque them down by hand, just knowing how much hand torque is enough. The manifold studs are the same, suck 'em down by feel, then re-"torque" them after running a while.

 

[PeterK]

Brass nuts are spec'd for the TR3-4 exhaust manifold. Never had a problem with them, and the studs are long enough so there is plenty of thread.

I learned early on in my VW years to always use brass nuts on the exhaust becase steel will eventually weld itself to the stud and brass will remove more easily. Of course, that was before anti-sieze was available. Still I've never had a problem using them. Intake is another matter all together; I use steel.

 

[Aldwyn]

That's not stupid, Dale... you simply didn't know!

I'd say leave em on until next time you replace the air filters. At least you'll have the pretty brass nuts for a little while. /ubbthreads/images/graemlins/smile.gif

 

[Brosky]

Dale, I mean no disrespect whatsoever to Bill, but I bought the same new studs and brass nuts from TRF that my Brit repair guy requested. He won't put anything but the factory style brass nuts and new studs in when he replaces manifold/gaskets/headers. He did allow me to have the little hold downs powder coated so that they wouldn't rust, but that was it. As a bonus, they do look much better too!

Dry those eyes and let it go. I believe that it will take a lot of driving before you have any issues, if at all.

 

[Guest]

Actually, Moss lists both brass and steel nuts as interchangeable in this application. Every time I have bought the complete stud collection for the intake/exhaust manifold installs, TRF has sent steel. In my application, custom intake manifold (triple) and custom exhaust manifold (Falcon headers), brass would not fit. Plus, never was a big fan of jambing brass against aluminum. Plus, there is now way in heck to fit brass nuts under the Falcon header without drastically cutting down the brass nut and thus weakening it. I even had to resort to slightly shorter all-steel lock nuts with shallow flat washers in 3 of the locations under the bottom of the header tubes to get a purchase on the studs. Quite a feat to get those things on. I certainly have seen brass on manifold bolts, even had them on my "free" TR3 engine, but in custom installs, they are not ideal and in regular installs they are preferred by some. Please see the pic (albeit rather fuzzy, blind shot) of the all-metal lock nut and the clearance that just ain't there to put in brass. These are true #8 quality locking nuts I obtained from a specialty shop. Ya gotta have good studs to use them or they will strip a cheap grade. I have checked them several times and they just won't back down.

I even had to face the spanning clips a bit for more room. The studs are just a hair from touching the pipe.
Bill

 

[Brosky]

Bill, now you've got me thinking about mine. I wonder how he got under there with the bigger brass nuts??? More to follow, cause I know that they are there, but how? Maybe my Pacesetter headers allow more room? I'll try to take a pic from the same angle as yours.

 

[vettedog72]

First time off and on with the manifold, I reused the old stuff (OEM brass) and had to start some nuts before the manifold was pulled down becasue there would not be enough room to start the nut other wise. The brass nuts lasted more than 80,000 miles having to be retorqued occasionally. I replaced all with steel, studs and all when the machene shop broke a few studs removing them to shave the head. I never had a problem with the brass nuts. I ordered replacement studs only for the broken ones along with a major order and received some odd ball studs that had the correct part number on the bag but the stds did not relate to the motor. I went to a good (a very large one I might add) hardware store and got everything I needed. I was surprised at the number of choices available at the hard ware store as far as size grade and type of fastners.

 

[Tinster]

I'll try to take a photo later of the brass
nuts in place.

The Boss is hollering she wants equal time!!

d

 

[Tinster]

Well Bill, you certainly called this one correct.
Look what the camera under the pipes showed up on
the fully torqued brass nuts. You cannot see these
nuts when you install them. Feel only.