Adjustable Cam Sprocket Install (another long tech post)

[camron at worldaccessnet.com (Camron D. Crouse)]

With the plans to change my own timing belt called off, I am wondering 
about the installation of my new adjustable cam sprocket. If I do indeed 
have a shop change the belt for me I'd like to save some money on labor 
and install this spocket myself. The biggest PITA for me to change a 
timing belt is all the belts at the bottom that are in the way, and the 
pulleys that need to be removed.  Well, the whole damn belt doesn't have 
to come out of the car in order to change the just the Cam gear, right?  
Rotate crank to TDC, loosen the tensioner (I even bought the special 
tool) - heck I suppose I could change that too while I'm at it - Slip 
the old belt off, remove old cam sprocket, install new sprocket at stock 
timing setting in its place, slip old belt back on, retension, and good 
to go??

On the other hand...

I have heard that once a tensioned timing belt has been loosened, it 
should not be re-used, 'specially an older one.  Truth or hearsay?

Oil seals - how tricky to replace if not removing valve cover, (at least 
for the camshaft oil seal)?  My local parts guy says it's no big deal, 
you don't really need the special seal extractor or installer tools if 
you are careful with typical hand tools.  Anybody have experience?

How do I get the cam sprocket bolt off without rotating/spinning the 
cams in the process?  Likewise, how does one get the crank bolt loosened 
without rotating the crank?  And putting the bolts back in??

When I put the belt back on, well it's a toothed belt, so how does one 
ensure that there is the proper number of teeth on the belt between TDC 
marks on cam sprocket and TDC mark on crank vibe dampener?  I suppose I 
could mark the belt and reinstall it the exact same way so that the same 
teeth mesh, but won't adjusting the tensioning roller tug on both cam 
and crank sprockets and mess up the timing relationship between the 
two?  Does that make any sense at all?  I guess I don't understand how 
tensioning a toothed belt on the firewall side of the car would also 
allow the belt to become tensioned on the radiator side, unless one or 
both spockets rotate towards each other.  And what about the small space 
between the Intermediate Shaft Sprocket and the Crankshaft Sprocket? How 
do I ensure the proper belt tension beween these?

Clear as mudd, huh?

Let's see if I can draw this (pretend we are looking at the timing belt 
on the engine from the side) Engine as it normally appears on car:

( O )  Cam Sprocket
  \ |
  o)|  Tension Roller
  / |<-Timing Belt
(o_O)  Intermediate Shaft/Crank Sprockets
 

Maybe you have to start out with the cam sprocket rotated slightly 
advanced...,

( O )  Cam Sprocket (slightly advanced)
 |  |
 o) |   Tension Roller (untensioned)
 |  )<-Timing Belt (pretty loose)
(o O)  Intermediate Shaft/Crank Sprockets(TDC)
  ~  <-Loose Loop of timing belt??

...so that when tensioned, the cam sprocket is rotated back to TDC...

( O )  Cam Sprocket (TDC)
  \ |
  o)|  Tension Roller (tensioned)
  / |<-Timing Belt (tensioned)
(o_O)  Intermediate Shaft/Crank Sprockets(TDC)

Okay, maybe there just isn't really that much slack when a loose belt is 
placed over the sprockets?  How much slack should I expect?  Maybe the 
belt is damn near tight the moment it goes over the sprockets, and there 
really is no need to worry?

( O )  Cam Sprocket (TDC)
 |  |
o|  |  Tension Roller (untensioned)
 |  |<-Timing Belt (pretty snug)
(o_O)  Intermediate Shaft/Crank Sprockets(TDC)


Does any of this make any sense at all?



Thanks everyone for putting up with these durned novels...


- Camron from Vancouver, WA USA
    '86.5 Black 16V 2.0