[ROVERNET - UK] Vapor lock/water cooling

[denlet]

Bonjour,

(sorry for my english)
Can you give your advice on my question?
You can see on  pics of V8 engines
http://www.britishv8.org/Other/LanceLaCerte.htm
a hose between front radiator and the cente of the inlet manifold.
I had cleaned the inside of this pipe on my car: you have one enter,without
outflow and no communication .(usualy full of chalky mud)
Is the function of this space the same of the separate expansion chamber (
used on SD1 V8 ).
Another question : is it better to fit a separate expansion chamber?

    merci pour vos réponses
    félicitations pour cette t belle restoration, Lance

    denis