what are heads made of
 

my brother has a couple of 1988 300e's he is going to take to the junkyard, but he wanted to know what the heads are made of. he says the price of aluminum is pretty good so if he sells them seperately he can make a little extra cash. i dont know the answer but i assume they are aluminum...
\thanks for the help

The heads are aluminum but he will not get the best price b/c of the other metals in them, so he will likely get a "mixed metals" price.

i dont know how much he can get but probably better that scrap metal prices... ill have to let him know, thanks

I have heard of metal recyclers paying the "clean aluminum" price for heads, but with the valves and other non-aluminum components, I don't understand why they aren't "dirty aluminum".

Aluminum heads are made of cast aluminum alloy. Working from memory, the chemistry is somewhere around 11% silicon, 3% copper with the rest aluminum.

Clean aluminum to the secondary market generally means all other metals and nonmetals are stripped from the aluminum piece. The most important metal to remove is steel. Iron is considered a poison to aluminum alloys. Small amounts can drastically reduce the desirable material properties of an aluminum alloy. Most foundries try to limit the composition of their secondary aluminum to one percent iron.

Removing steel is very difficult on an aluminum head. The valve guides and valve seats are pressed into the head. Anything done to remove the steel will help raise the quality of the scrap. If the aluminum goes through a shredder and magnetic separator, it may not matter.