My mate recently bought a Ginetta with a ford pinto and webers. The other day he noticed a strange looking valve which appeared to be hissing when accelerating.

Firstly this is on the inlet manifold so if it is releasing pressure then i am a bit worried he may go bang.

Secondly it appears to have a pin in the middle but this is siezed, it is 10mm.

i think it is some kind of adapter for a vacuum guage but cant be sure. Any info would be great.