[alfa] Re: 164 Tensioner stud sourcing?

["V. Lalo Ruiz" <Lalo@xxxxxxxxxxxxxxx>]

Graham Davis Wrote:
>I measured only moments ago is 7mm x 1 - and it may be the same for the
>detensioner locking stud.

I miss-wrote.  Yes, I know it's M7x1.0, that's what I measured the other day
as well.  My fingers were working faster than my brain when I wrote the email.
Since I have NEVER physically seen an M7xanything fastener in my life(until I
tore apart my Verde), I got the pitch wrong when I typed it out.  I stand
corrected.

>You ask why but
>as an ME you already know the answer - fasteners are chosen to meet a
>design strength requirement.  In this case, 6mm would be too small and
>8mm would have been way too large.

First of all, it was a rhetorical question.  Second of all, not only am I an
ME, but one with a Masters Degree in the discipline.  So yes, I would tend to
WANT to believe that the reasoning you suggest did in fact cross someone's
mind.  But having practiced mechanical engineering for the better part of 14
years, having to choose exactly an M7x1.0 fastener on the notion that the
strength requirement on the cam covers is that critical is just plain silly.
No, in this case I tend to agree more with Gwynn.  They needed to get rid of a
ton of M7x1.0 fasteners and the cam covers was a good place to start...

The tensioner stud is another matter.  M7 on one side and an M8 on the
other????  What's the penalty for choosing an M8 to M8 stud for this
application?  What?  Save weight?  Perhaps they thought that using an M8 in
the block would give too much margin from getting stripped out and thought
that if they did that and no one stripped it out, then some of the car's
character would be lost. ;)

Anyway, it's hard to know what reasons existed for making these seemingly odd
thread selections without actually speaking to the engineer that made them.
Maybe they were betting on M7 fasteners becoming a popular and thus standard
size by now?  Maybe an M8 thread in the block would have cut into an oil
passage or water passage?  Whatever.  It is what it is and all I can do is sit
there with my thread gauge in hand and wonder:

"What the hell were they thinking?"

-Lalo
'88 Verde
www.LalosGarage.com
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