Artemia Salina wrote:

Dumb question I guess, but why do engine manufacturers make
valve stems that are filled with sodium (I think only exhaust
valves are sodium filled). Is it a heat expansion issue?

Thanks.

--
0:-) 0:-) 0:-) 0:-) (-:0 (-:0 (-:0 (-:0
0:-) Artemia Salina (-:0
0:-) Surrounded by Angels (-:0
0:-) 0:-) 0:-) 0:-) (-:0 (-:0 (-:0 (-:0

It is a misnomer, the stems were generally only filled to 60%
of the cavity space which included that in the valve head.
At operating temps, the sodium was molten and transfered heat
from the valve head to the cylinder head via the stem & valve
guide.

Tom