[Gmecm] Reluctor / rotor phasing

[bcroe at juno.com]

Inserting the distributor on a different tooth will change 
the angle it must be turned in the engine, but it will 
have no effect on reluctor / rotor phasing.  That is 
determined inside the distributor, and by the range 
of spark advance.  Mechanical advance doesn't change 
phasing, since the rotating poles and the rotor are locked 
together.  Phasing is definitely affected by a vacuum unit. 

Phasing is more difficult with electronic advance, because 
BOTH rpm (was mechanical) and vacuum advance change 
the phasing.  The rotor overlaps the spark wire terminal 
for quite a few degrees of rotation.  You want to have a 
minimum overlap over the entire advance range.  That 
can be adjusted by adjusting the fixed pickup coil position 
(similar to the vacuum advance).  I have a transparent 
HEI cap for this, but a big hole works too.  

Bruce Roe

13 Sep 2005  Darryl M Gilbert <dgilbert78 at juno.com> writes:
>  I did this once when i was checking an ignition problem
> and found I had my dist 1 tooth out, so the phasing was 
> off