Re:N/A v. Turbo heads...

[brv@chrysler.com]

"..  Does anyone know why or what the advantage of sodium
> filled valves is?"


The valve stems become "heat pipes" with the sodium inside.  The liquid
sodium changes into a gas rising to the top of the valve where it is
cooler and the valve guide can absorb the heat load.  The sodium goes
back to liquid state as the heat is removed and falls to the bottom of
the stem where the heat is starting the whole process over again.
Basically, you have a self priming and pumping heat transfer device
which helps keep the valves from burning up under high load (high heat
as in max boost) conditions.  Heat pipes have been used for years in
many industries as they are simple, cheap reliable devices which are
actually very efficient at moving heat from A to B.

That's why our valves tend to be a little more expensive that those for
a run of the mill variety!

HTH

Brian VInson
86 5KCSTQ w/ sodium filled valves......:-)