After speaking to someone today regarding inlet valves, they are under the impression that the original cosworth inlet valves were sodium filled and the aftermarket ones are stainless steel.



If they are different, is it worth paying for the sodium ones?

 

Exhaust valves are sodium filled, inlets are solid IIRC
Yes, the sodium exhausts are necessary (and expensive )

 

As above, think their all the same. Would only go for genuine cossie ones unless your going for bigger inlet!

 

I knew that the exhaust valves were sodium filled for better heat dispitation, but thought that the inlet valves were solid stainless steel.

 

northerner,
yes you are correct.
Not sure if standard inlets are technically 'stainless' steel, but solid yes.
Valves are generally nickel alloy rather than stainless IIRC