OK copper is better aye? or so you say.

Karl Snarl

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Ok guys, the real advantage of a copper head gasket is not thermal regulation. I keep seeing that everywhere. Let me explain why before I move on to the real benefit. The exposed surface area to the atmosphere is not even enough to give a one degree drop in temps. Why yes copper is slightly better at thermal transfer than aluminum, the thing is, uh you are transferring it to aluminum from aluminum. The aluminum can only pick up the exact same amount of heat per unit of time as before when using an aluminum head gasket. Your jug and head are, ding ding, aluminum!!!! woot woot, same rate of thermal transfer per unit of time as before, because physics says it cannot dissipate any faster, because its absorption/black body rate is the same as before!!!!

Now to the real benefit, it comes in many thickness already cut for you, making setting squish a breeze. It last a long time and can be reused simply by heating it up to it's phase change temp and letting it cool down. It seals just as well as aluminum does, and maybe just a tiny bit better, but not enough to even give a horse b***s about.

So if you are going the copper route, thinking you will massively reduce the temps on your overly lean engine. I suggest not worrying, and just jetting your carb correctly. Because aluminum and copper perform almost identically. The only advantage is copper can be reused when annealed.
 

Cisco

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can be reused simply by heating it up to it's phase change temp and letting it cool down
I have seen many video demos where they heat the copper cherry red and immediately quench it. I thought you have to let it cool slowly to anneal it. Which is right (does it make any difference with copper)?
 

Street Ryderz

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I have seen many video demos where they heat the copper cherry red and immediately quench it. I thought you have to let it cool slowly to anneal it. Which is right (does it make any difference with copper)?
That's a good one! It's very hard to find the right answer sometimes with the internet having so many opinions that are not necessarily the right answer for your exact query, I can't say I'm right here ether but IMO copper only needs a max temp of 650f not glowing or cherry red for proper annealing then when it comes to very thin like the head gasket I like to just let it cool because it seems more pliable compared to quenching it, now I could be wrong here but when I think of quenching it's to make it harder not softer and again with the head gasket in mind we want it to fill in any imperfections in the mating surfaces more than anything and IMO the more pliable the better.
 

Karl Snarl

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I have seen many video demos where they heat the copper cherry red and immediately quench it. I thought you have to let it cool slowly to anneal it. Which is right (does it make any difference with copper)?
That's a good one! It's very hard to find the right answer sometimes with the internet having so many opinions that are not necessarily the right answer for your exact query, I can't say I'm right here ether but IMO copper only needs a max temp of 650f not glowing or cherry red for proper annealing then when it comes to very thin like the head gasket I like to just let it cool because it seems more pliable compared to quenching it, now I could be wrong here but when I think of quenching it's to make it harder not softer and again with the head gasket in mind we want it to fill in any imperfections in the mating surfaces more than anything and IMO the more pliable the better.
@Street Ryderz nailed it, and I'll explain why letting it cool and not going cherry is the way.

The way I do it, I take a bar of Irish Spring, yep, regular bath soap. The reason why, it seems to burn off at just the right temp for the phase change. Copper, unlike aluminum, gets softer after you heat it to a phase change. Quenching, actually causes some work hardening, by the forces acting on it as it cools rapidly. Letting it cool on it's own, allows the crystals to move around and settle in place. Ok, now how I do it is, I rub the dry soap bar on it on one side, just a thin layer like a light coating. I heat the other side, when the soap begins to ash, I'm done. It doesn't need to completely fully ash up and go white, just a light grayish black is fine, that's plenty of heat to soften. It's about 600-700 degrees where the soap begins to ash. You will notice it goes from green soap, to black, to starting to lighten, the lightening is when you have just reached, or about to reach the phase change temp. I know, I know, super extremely scientific way of doing things. I learned it when I was studying blacksmithing. It also is a good way to surface harden gears. Coat them in soap, put them in the coals, and when the soap begins to lighten, take out and quench. Do that 2 or 3 times and you get a few thousands of hardening on your gear teeth. That's how they did it in the olden days. And it's how I still do it. Cheap, and works just as well as the fancy powders, but I can get my soap while grocery shopping.

Oh and when you go cherry, you start oxidizing the metal, meaning it gets weaker and thinner each time you do it. You only want to heat to the first phase change, not higher up on the scale. red hot is way past where you need to be.

And when I say light coating, I mean a light, light coating, you're not trying to wash the gasket, you are using the soap as a heat indicator. You can always just buy the heat pencils and you know for sure, but why when you have soap in the bathroom.
 

michael whiteman

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Karl's right on. The blown funny car that ran out of our shop sure as hell did not have aluminum head gaskets. They are all copper because copper seals the best to aluminum surfaces and comes in various thicknesses. Period.
 

Wrench

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It don't matter if ya let it air cool or quench it in water. 100% copper turns out the same It's annealed.

Quenching it in water removes 75% of the carbon soot. So it's easier to clean up than letting it air cool.
 

Karl Snarl

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It don't matter if ya let it air cool or quench it in water. 100% copper turns out the same It's annealed.

Quenching it in water removes 75% of the carbon soot. So it's easier to clean up than letting it air cool.
The stress applied while quick quenching, actually ends up slightly work hardening it. It is softer if you let it cool on it's own.
 

DieselTech

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Fwiw: the easiest way I've seen to anneal copper/ way to tell its annealed, is set copper on heat plate/skillet & slowly heat till you see copper color in gasket, flash off & gasket turns a rainbow color.
 

Karl Snarl

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Fwiw: the easiest way I've seen to anneal copper/ way to tell its annealed, is set copper on heat plate/skillet & slowly heat till you see copper color in gasket, flash off & gasket turns a rainbow color.
Juat make sure there are no eggs and bacon in the pan before frying your gasket. It really ruins the copper heart attack flavor the anneal gasket takes on after a good Sautee.
 
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