I'm swapping blocks and distributors, re-configuring an inline four gas VW
motor for my van.  92 digifant 1.8 liter heads onto a 94 Jetta ABA 2.0 liter
block.  Keeping the 1.8 head will raise my compression ratio to 10:1, I am
told.  The digifant EMS does not have a knock sensor provision.  For now I
am planning on running the new motor set-up on premium 92 octane fuel or
maybe mid-range..I am daily driving at around sea level.   I often go to
elevation in the van... but not too often above about 6000'  maybe a few
times per year.

  So the Bentley book calls for 6-8 degrees BTDC on the 1.8 and the 2.0
liter.  They are both in the 9-9.2:1 compression ratio range..  It has been
some time since I timed a vehicle.  The last ones I messed with still had
points ignition.  I used to have to change the timing on my air cooled
German cars...Beetle, Splitty Van and a 356 S-90 Porsche when I went from
altitude down to sea level because they would knock or run too hot
sometimes...but I have forgotten what the reasons and the direction is to
adjust the timing for pre-ignition and regular vs premium fuel.

  Anybody care to give a short run-down on how to adjust the timing for
various conditions..like raised compression ratio, regular vs premium fuel,
trading power for peace of mind about knocking motors, etc etc?

 I should be OK just running premium for now, but I might like to switch to
regular if the motor makes sufficient power on the cheaper fuel and doesn't
want to destroy itself too quickly by pinging badly..  If I do try to
'shade' the timing towards regular gas or if I plan on heading through some
high mountains, what's the drill?

  Thanks in advance
  Don Hanson