[alfa] Re: Spica injector numbering (or differences)

[Jon Pike <jhpike@xxxxxxx>]

> In regards to injector numbering on the Spica cars, I venture to guess it is due to the need to precisely match fuel delivery 
> for all four cylinders using injectors that may not be so precise.  The injectors would be matched to the pump during 
> manufacturing/testing, and the pump cylinder liners would be adjusted to give even fuel delivery from all four injectors.  The 
> injectors would then be numbered so they can be replaced correctly if ever removed.
>
> Note that this may explain why Wes has been quoted as saying that factory pumps can vary in their fuel delivery across the 
> four cylindres by more than 10%.  It may have been dialed that way to match the variability of the original injectors.  I would 
> hope that Wes's pumps are sold with matching injectors.  I think the old Alfa replacement pumps came without matched 
> injectors.
I was looking at mine a while ago,  since I have the manifold off while 
I'm building the engine.  I noticed that the tip of  each nozzle has a 
different sized "cone" at the end.  By cone,  I mean the shallow angled 
indent at the end,  where the actual orifice is found at the bottom of.  
All my orifices look pretty much on center,  and look the same size... 
But having four out of four being different cone section,  that seems wierd.

On another note,  I recall Wes at a tech session commenting on how 
rarely the injectors go bad... and that you usually don't need to get 
refurbished ones.  I don't know if this applies to matched delivery and 
spray pattern..    And he does have refurb ones available..
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