A simply shocking source of sodium metal.

[jdurg]

This completely shocked the living hell out of me. Earlier tonight, I was helping a buddy out with a project he was doing on his car. His goal was to replace the standard engine valves with some higher performance valves to increase the horsepower and he asked me to help him out. I oblidged and went over after to work to lend him a hand. As he was taking one of the valves out of the box, he dropped it on the cold concrete floor and then something unexpected happen. The lead mallet that was sitting on the table next to the work area got knocked over and fell down onto the valve, bending it a bit. My buddy was a bit pissed at this series of events and slammed the now useless valve against the wall. I guess he hit the corner of the wall because a crack showed up in the valve stem. We thought nothing of it and just chucked the valve into a corner.

 

A few seconds later, we both heard this little hissing sound coming from that corner. When we went over to take a look we saw a water droplet come down off a hot water pipe over the corner and onto the valve. When the drop hit, the valve started hissing right at that little crack. Wondering what the hell that could be, I asked my buddy if I could just cut open this broken valve. He said 'sure' so I took a hacksaw and cut it open. Inside was a decent sized lump of sodium metal!!!!!!! I took some tongs, ripped out a small chunk and threw it in water. Sure enough it fizzed, hissed, popped, and burned with a bright yellow-orange flame. I don't know why it was in there, but they have sodium metal inside engine valves. I kid you not. I don't know if it's inside EVERY engine valve, but in these high performance parts it sure is.

[Phi for All]

I wouldn't think sodium would be very good at high temps. Wouldn't it melt pretty easily?

[akcapr]

http://en.wikipedia.org/wiki/4-stroke_cycle_engine_valves

 

guess they keep it in there to pull the heat away. Hmm interesting..

[RyanJ]

I wouldn't think sodium would be very good at high temps. Wouldn't it melt pretty easily?

 

Yes... it does, its used to conduct heat away in certain nuclear reactors and is pumped arround too cool it down, its not only an efficient conductor but its low melting point if perfect for the job.

 

That may be the reason its included here because of its brilliant thermal conduction properties?

 

Also, great find jdurg!

 

Cheers,

 

Ryan Jones

[akcapr]

Ya i heard about being used in nuclear reactors pretty neat

[warut]

Theo also has such valves in his collection:

http://www.theodoregray.com/PeriodicTable/Elements/011/index.s7.html#sample10

[rthmjohn]

just how expensive are these engine valves, though? Do you think it would be worth buying one for the amount of sodium that you get?

[jdurg]

I'll have to ask my buddy what the price was for the valves he bought. He was pretty pissed to have that one get damaged (hence the heaving into the wall when it was bent) so I can't imagine that they are cheap. However, it is now a valid source of sodium metal to those who can't otherwise get it. Perhaps it would make a trip to a junkyard worth it? (As once cars are "junked", the engine and valves are typically garbage anyway).

[Charles Sansom]

They've been doing this for many years. I remember learning about it in Propulsion Engineering school in the Navy. The sodium melts at engine operating temperatures and splashes around inside the valve to help carry away excess heat. It's typically the exhaust valves which have the sodium inside them.

[Enthalpy]

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