Re: Cams, John L.

[jlandry@domain.elided (John A. Landry)]

When he stopped taking his medication, strange voices in
jmbrodsky@domain.elided's head said:

>        Cam grinders can 'copy' cams just like Home Depot copies your house key.
> The one side has the original cam and the other side has the 'blank' cam.  The 
>machine runs the grinders and pointers and voila, copied.  Not too much magic in
>that one.  The question I have for you is why you would question the 'pull the 
>print' that the tech spoke about.  Each lift and all the angles have to be 
>stored somewhere.  Are drawings out of the question?

No Joel... it's not that I'm questioning Federal-Mogul having a print.  I'm
sure he actually pulled something because he put me on hold and cam back
ruffling a piece of paper.  What surprised was the *lack* of information
they had about the cam.  If you buy a cam from Crane or someone like that,
you get this nice little card with the cam that tells you everything you
ever wanted to know about it and then some.  This card is indispensable if
you plan to degree the cam.

The FM stock cam didn't have sort of specifications packed with it.  That's
why I was forced to call them and then the tech pulled the print.  With the
information he gave me from the print, it's not adequate to verify all the
important manufacturing aspects of this cam.  In retrospect, it's clear now
that all FM did was make a master cam for their production by copying a
stock factory cam.  They probably took a few cursory measurements for
verification purposes and made a print.  This is all fine with me as long
as I have the detailed original factory specs to verify their work against
(which I still lack).  I don't inherently trust anyone's work or quality...
especially when it's going to get buried in my new engine!

Failing someone coming up with specs for me, I'm planning on measuring the
old cam directly or slipping it back into the block first and take full
measurements on it there.  Obviously it has plenty of wear, but if I take
that into consideration, I still should be able to get a pretty good idea
of what to look for.  Then all I need to is see that the FM cam matches
reasonably well.

I know this all sound pretty ridiculous to many on the Digest, but I don't
care.  I have plenty of time to spend on this rebuild project and I'm going
to do what I feel is right.  There's no way I'm going to simply throw
something that important into my new engine without checking its quality
first.  When my block, crank and heads come back from the very reputable
machine shop I'm using, I'll be checking every bit of work they did too.

Shoot, just ask Mike Ryan about what he found when his engine cam back from
the machine shop.  As I recall they installed a couple of pistons upside
down on the connecting rods.  Assembling an engine with a mistake like that
could destroy it in short order.  That's great attention to detail all
right!  Maybe this affinity guys like Mike and I have for checking and
double checking everything is because we were trained as pilots and had it
drilled into our heads that one overlooked minor detail can result in
untimely death?

Take care,

John L.
-------------------------------------------------------------------------- 
jlandry AT halcyon DOT com    |
Conservative Libertarian      |  
Life Member of the NRA        |        All the GOOD things in life
WA Arms Collectors            |              are DANGEROUS!
Commercial Helicopter - Inst. |  
www.halcyon.com/jlandry/      |