Distributor Phasing Question

Bill:

The way this works is by locking the distributor, but aligning the rotor for the midpoint of the advance curve. If you have say 45 degrees of total advance, the tip of the rotor should line up with the post @ about 22 degrees BTDC.

Then the trigger is rotated to fire @ 45 degrees BTDC. Not the distributor, just the trigger in relation to the reluctor.

The ignition box can't advance the timing. All it can do is delay the signal to the coil - retarding the timing. So the mechanics of it are actually set up to provide 45 degrees of timing, With the electronics actually removing timing.

The rotor is phased to the midpoint of the curve, and the distributor is locked. Since the phase angle is half the crank angle, that means the tip of the rotor is never more than 10 to 12 degrees one side or the other from the post.

B.