On Fri, 9 Jan 2009 19:34:01 -0800 (PST), "
wrote:

Okay, then YOU name the damn things!

Right now I got a couple questions: VW heads are nearly pure
aluminum. I've got a pile of the things but odds are, every single
one of them is worth a $25 bill... or will be. Point is, I don't much
care for the idea of cutting them and melting them down.

When I make something SERIOUS out of aluminum I usually use old
pistons, which is a pretty hard alloy with a MUCH lower heat-transfer
ability than VW heads.

So what's a good alloy? Ideally, something cheap & commonly available
(and doesn't say 'Coors'!)


-Bob

according to some evening research there are two aloominum alloys used
in automotive(water cooled) heads. AA319 which has Aluminium plus 6%
Si and 3. 5% Cu and AA 380 Aluminium plus8.5% Si and3% Cu

another source shows an old piston alloy 242 as a popular aircooled
head alloy.

lyc and cont use a 2 series alloy.

one reference mentions 220.0 -T61 as the original widely used
aircooled head alloy though now supplanted by 242.0 and 243.0 which
supposedly have better elevated temperature heat strength.

242 alloy is Aluminium with Mg 3.0%, Si 0.5%, Fe 0.5%, Mn 0.2%, Zn
0.1%, Cu 0.05% (percentages by weight)

so as a wild guess your silicon containing piston alloy mixed with
some 2024 or 6061 might just be entirely satisfactory. experimentation
will tell.

Stealth Pilot