Re: valve adjustments

[Simon Favre <favres@engmail.ulinear.com>]

Mike Hooker wrote:

>i am wondering how you various digesters accomplish valve adjustments.
>do you buy a whole set or do you make the measurements and order the
>shims, tying up the car for who knows how long?  i have been holding off
>doing mine, but feel i better get it done.  i was wondering if we
>couldnt all kick in the shims we have and built a nice master set for
>the use of the list.  we could pass it from one to another.  i am sure
>we could get together more than one decent set.  am i out of my mind
>here?  also, are 4 cyl and 6 cyl shims different?  a guy told me you can
>rub a shim on a flat surface like glass and real fine sandpaper, to
>reduce its thickness.  are they surface hardened?  can this work?

Hand lapping shims is tedious in the extreme.  Besides, what if you need
a thicker one?  ;=(

The most important thing to remember when measuring the valve clearances
is to keep from having any crumbs of carbon between the valve and seat
as this will screw up the measurement.  My way of avoiding this is to
rotate the motor until a given cylinder has both valves closed, THEN
pull that spark plug.  The other way is to loosen all the plugs, then
reconnect the wires and run the motor a few seconds to burn off the
crumbs that dropped when you loosened the plugs.  You can then remove
all the plugs.

I believe most AROC chapters already have local collective shim sets.
You forgot to mention where you are from.  If you surrender this
valuable piece of information, someone local to your area will probably
tell you who to call to access the nearest set.  If there is still an
Alfa dealer/service center in your area, they may have shims to sell.

If you keep records of all the shims in the head, then you can measure
the clearances and figure out which shims you need from the records.
You can then put the valve cover back on until you get the shims.  After
putting them in, you may still be off 1 or 2 thousandths, but that's
usually close enough.  To get it right usually requires an iterative
process that means having lots of sizes available, hence the collective
set.

In the "good old days" of my misspent youth <g> I used to just walk
around the corner from my house to Griswold Company in Berkeley and sift
thru their collection, paying Jon Norman for the ones I needed on my way
out.