To anneal or not to anneal? Options

[lsintampa]

75 914/4 2.0

Will soon be backdating my exhaust with SS HE's

I have new sealing rings (for the exhaust headers) and gaskets for the muffler, and new copper (plated) nuts or copper not sure but those from the big bird.

I've read several threads about annealing the sealing rings, using copper RTV, and all sorts of ways you all have mounted up your HE's.

The captain said something to the effect of mounting them, after you run them for a while, tighten them up again. I think in effect this is part of the annealing process.

I think I'm going with annealing up front and then tighten them up again once they motor has been running a bit.

Not sure this is the best method, or if one is better than the other, but it sounds right to me.

Question I have, that I've not seen addressed anywhere is that when I take the stock headers and try to test fit them to the motor, it is really tight getting the headers onto the studs. So tight in fact, I never really got them onto the studs for fear of mucking something up in the process.

By tight, I mead that the ears on the headers want to rub on the valve tubes.

Is this "normal"?

Thanks,

Len

And if you want to put your .02 in on the annealing / not annealing debate feel free!

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[rick 918-S]

anneal them

[bulitt]

Shouldn't have to if they are new. (IMG:style_emoticons/default/confused24.gif)

[Black22]

Anneal.

[McMark]

Certainly doesn't hurt. But I don't do it.

[mrbubblehead]

i say anneal. and use a dab of gasgacinch to hold em in place. i also agree with the captain about re tightening after a few heat cycles...

[ThePaintedMan]

If logic holds true, and the heat in the exhaust after running anneals them, it makes sense to me to just go ahead and do it before the exhaust goes on. I think it helps to take a little stress off of the exhaust studs when you're trying to get the initial seal. Then, as Cap'n and others recommend, re-tightening them ensures that everything stays leak free.

I already told Len this, but thought I'd share with everyone. Rather than trying to do them one at a time with a propane torch, you can just stick them on the grill for 5-10 minutes and you'll get the same result. They'll turn blue, then drop them directly into a mason jar of water and install.

[Rand]

Since it is proven that it is unnecessary, then why bother? But if it makes you feel better then you can say you did it.

Certainly don't re-use old ones, but new ones work perfectly fine without annealing as they compress and seal perfectly fine. Don't let anyone BS you otherwise.

[ThePaintedMan]

It might be unnecessary, but it can't hurt, I guess is my point.

What is far more necessary, and probably downright essential is to file the tops of each set of heat exchangers so that they are level and match perfectly, a la Jake's rebuild video. Like all things exhaust, heat +vibration tends to warp thin pipes over time and they won't seal correctly unless both surfaces are level/matching.

Len, I hadn't told you about that part because I forgot, but essentially all you need to do is run a long file over the two pipes on one side's heat exchanger, checking for low spots. You can do this by coloring the top of the HE flat mating surfaces with a sharpie. Then file till there are no low spots remaining. I can show you next time I see you if this doesn't make sense.

[Rand]

Like I said, if it makes you feel better. (It's equally important to hold your mouth right when you do it. (IMG:style_emoticons/default/wink.gif)

If you don't already have a mapp gas torch in your garage, you need one around anyway. Besides being a great bbq lighter, and being super helpful for getting tough fasteners apart, they make very quick work of annealing exhaust seals.


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[lsintampa]

I didn't mean to start a fire storm... either way seems to work fine.

The Question I had though was I find the headers to be tight fitting with the ears between the valve tubes..... and was wondering if that's SOP.

[Rand]

I didn't mean to start a fire storm...

This is no firestorm! Just garage talk. (IMG:style_emoticons/default/beerchug.gif)

[ThePaintedMan]

No fire storm here. Just differing approaches I think (IMG:style_emoticons/default/beerchug.gif) Besides, most of these guys, including Rand, know far more than I do. I wouldn't have made it this far without their help.

I'm not quite clear on what's actually giving you issues Len. The ears of each HE tube are hitting the pushrod tubes? That shouldn't be so. Sometimes they can be a bear to get over the studs, and you have to try a couple of angles to get them on all the way (especially if the studs have ever been drilled out or a Time-sert/Heli-coil was installed at a different angle than the factory). Otherwise they should go on fairly easy. The harder part is getting a socket on the exhaust stud nuts. The nuts from the factory were something like 12mm, which gives just enough room to fit a socket on. A 13 mm won't quite fit on some of them, so it's pretty important to have the correct hardware.

Do you already have the engine in the car? If not, you probably want to wait to install the exhaust when everything is in. As much of a pain it is to work on your back, it's a lot easier than trying to work on your side with the engine on a dolly. I can help you with that.

[lsintampa]

Hey George,

When the HE's get here (I hope some time this week), I'll give you a call.

My old HE's were not attached to the header pipes. So I was just mucking about trying to fit the headers onto the studs. No gasket, just for alignment.

Getting the old headers onto the studs was quite difficult. The flanges (ears?) that are supposed to slip over the studs were hitting the valve tubes to the point that there was no way to get them to the studs without some force. In fact, I never got them onto the studs - the tubes seemed to be in the way.

Hard to describe, but that's how I remember it.

Given I'm going with a totally new setup, best I wait until the new HE's get here and we'll see how it goes from there.

As far as the seals go, I'll flip a coin when the day comes - as it seems it really doesn't make much diff.

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[rhodyguy]

when dressing the piping you need a big bastard file (big enough to cover the pipes) and need to do both pipes for one side at the same time in small increments. you'll prob note irregularities on the first gentle pass. clamping the he to a flat surface helps too.

[stugray]

drop them directly into a mason jar of water and install.

If you heat metal and cool it quickly you are not softening it, you are hardening it.

To anneal (make the metal softer) you should heat them and then let them cool as slowly as possible.

Stu

[ThePaintedMan]

drop them directly into a mason jar of water and install.

If you heat metal and cool it quickly you are not softening it, you are hardening it.

To anneal (make the metal softer) you should heat them and then let them cool as slowly as possible.

Stu

My mistake. That makes sense. I was just describing what I did after reading how others had done it. Maybe next time I'll just leave them on the grill to slow roast after I shut it off (IMG:style_emoticons/default/smile.gif)

Definitely changed the sound of them though when bounced and they're almost pliable enough to bend with hands alone.

[dlee6204]

drop them directly into a mason jar of water and install.

If you heat metal and cool it quickly you are not softening it, you are hardening it.

To anneal (make the metal softer) you should heat them and then let them cool as slowly as possible.

Stu

It doesn't really matter with copper whether you quench it or let it air cool to anneal it. To anneal steel you must let it slowly cool.


http://en.wikipedia.org/wiki/Annealing_(metallurgy)

[ChrisFoley]

If you heat metal and cool it quickly you are not softening it, you are hardening it.

To anneal (make the metal softer) you should heat them and then let them cool as slowly as possible.

Stu

Depends on the metal you're working with and the grain structure they form at different temperatures.
Your statement is generally true for steel alloys but not necessarily for other metals.
Copper can be quenched in the hot annealed state and it will not harden.

[lsintampa]

ahh,

I'm firing up the grill right now.

Dogs anyone?

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