just ordered some for my 71BB... is rtv high temp sealant necessary with these gakets or not..

 

I am not a fan of copper head gasket even though I was forced to use them. I feel they seep oil.
I use copper spray on them. NO rtv

 

I put some on last month, they leaked like crazy! I went back to steel with composite coating... or whatever its called and no leaks.

For the copper ones to work they need to match your headers perfectly... not the head ports but the header flange. Good luck.

 

Guys I am totally out to lunch. I didn't read header gaskets. Yes high temp RTV works fine.
Sorry.

 

Is there a corrosion problem using copper gaskets with aluminum heads?

 

I use copper headers gaskets. When I first installed they still leaked, so I added sealant to the gasket and they work perfectly. I also used at the header collector gasket.

 

the composite felpro one piece has always worked fine for me... I have had troble with metal ones. If you can get them to seal they are fine. If you don't feel like fooling around with it, just use the composite type.

If you do use the coppers, make sure you retorque them after a heat cycle, when the motor is ice cold

 

bad experience with copper. they cost a lot and mine never did seal. they are hanging on the barn wall. they look and work great there.

 

This is a subject about which I've heard so much BS that copper gaskets don't last with alloy. Is there a problem? Basic chemistry taught me about dissimilar metals in contact with an electolyte, etc, but what sort of timescale are we talking here? I'm currently riding something built in 1965 with an alloy head & using a copper head gasket. The gasket mating face on both the head & block is fine, no evidence of corrosion at all. My wife's 1973 version (all numbers matching and original), doesn't have any signs of corrosion, a mates 1959 engine is the same. Nothing I've seen from the 50's up until the mid '80s that used alloy heads with copper gaskets has shown any signs of electrolytic corrosion (some of the signs they've shown of Bubbas appenticeship have been awesome ). Still people tell me (& mechanics that have spent their lives working on these old engines) that copper gaskets are bad news with ally. We're all baffled as none of us have ever seen any evidence of a problem regarding corrosion. Maybe pure aluminium does have problems. Maybe with an electrolyte in continual contact (coolant in a water cooled motor, sea water in a marine environment, etc) there will be problems.
From my experience of alloy castings with copper gaskets I'm intending to use my copper header gaskets when I eventually get some alloy heads. If there are corrosion problems due to electrolytic effect, then it's going to take so long for it to become a real problem that I'll just be a long forgotten entry in the governments tax records kept in some dusty archive! If my mates '59 shows no signs of electrolytic corrosion after thousands of hours in the rain, countless miles on salt encrusted winter roads & being kept in a damp garage for most of its life, then how long will it take for a header gasket to cause problems when it lives in much drier conditions?
The most effective way I found of sealing headers/exhausts (and any other mating surface) is to ensure that the surfaces are true (which header flanges quite often aren't).
And there are advantages with copper: it can be annealed & re-used (which is great on a Sunday morning if there's nowhere open to buy a gasket from) &, even better, it's so darn easy to take apart (ever had to get a composite gasket fly cut from an alloy head casting? Another reason I stick with copper!).
Right, it's time to put that old copper head gasket on my arm.... helps with the old arthritis don't you know old chap!