Sodium Valves ... curious to know

Ah, forget it. Didn't read down in the thread far enough, to know that there had already been pyromaniac intervention.

 

Does my 1986 328 GTS Euro Version have sodium exhaust valves?

 

Nnly 308's up to 82'.They weren't installed in the QV or 328 engines

 

So did I hear someone say these are not found in the Quatro?

 

Correct, only in the 308 2-valve engines.

 

Good to know, looking at an 83 Quattro.. Probably have something else to worry about. Maybe I just buy another 348, I have no problems with mine now.. tks

 

Is there a way of identifying sodium filled valves? Can you tell if a previous owner has replaced them?
Thanks

 

There are several things that make them prone to failure: 1) the weld is at the hottest, weakest part of the stem, where the air is injected, 2) the walls were pretty thin to start with 3) the valve springs are much too strong (high rate for the pedantic) so the stresses higher 4) the guides are soft so the eccentric closing of the valve (with high spring forces) puts a bending moment on the stem which causes fatigue over millions of cycles.

To check with the valves in the engine you can use my method here:

https://www.ferrarichat.com/forum/threads/dereks-308-engine-rebuild.535247/

... but some solid stainless valves have a slight magnetic pull so it is not definitive. The 21-4N valves I sell have a small magnetic effect due to some tiny martensite crystals from the heating and forging process.