[alfa] Spark plug and valve interference

[Jon Pike <jhpike@xxxxxxx>]

OK.. this seems to be coming up a lot lately..

I just noticed a tiny polished facet on the edge of the ground terminal 
of one of my spark plugs.  Yep, about one mm by three.. made by the 
intake valve banging into the plug.  Engine is newly rebuilt.. about 750 
miles on it. 
I made index marks on the plugs so I could see where the electrode ended 
up, more for my own curiosity rather than performance.. and noticed that 
this one happened to line up in the worst possible clearance situation. 
(back of electrode at 45deg angle to valve)

I had been playing "musical plugs" with my only set,  new NGK BPR6ES's,  
and got (un)lucky I guess.  The thing is,  why does this happen now? I 
don't remember  hearing of this way back when I was into Alfas before.  
Are the plugs being manufactured with wider/rounder electrodes,  or is 
this something to do with my valve sticking farther out of the head? I 
did get new intakes when I had the head done (I was told they needed it) 
but they are stock sized. 
Can a new valve's larger diameter sit it higher out of the seat and 
cause this?  Are there regular style plugs that have lower clearance, or 
do I have to go for the Lodge 2HL's just to be safe? Or is there 
something wierd going on?

Wasn't following closely the recent posts, since I didn't have a problem 
(heh) now I'm having trouble searching the topic up from the archives..  
So, anyone had this go on, and what ended up causing it, fixes, etc?

Jon
77 Spider
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