Bob,
I just wanted to add a bit to Dick's comments (which are spot-on, as
always). The reason that you have to look at the phasing with the
Crane ignition is that the optical trigger is adjustable. Ie: the
position of the trigger relative to the rotor is adjustable.
Therefore, as Dick mentioned, it's possible to have the trigger
positioned such that it fires the coil when the rotor is between two
poles on the cap. Not a good thing. Here's how I adjusted mine:
1) Turn engine to your static timing mark. For me, I use 10 BTDC
because my engine is a bit modified. I'm not sure what the static
timing is stock (probably 14 or so I guess), but turn the engine to
your desired timing mark.
2) Make a mark on the distributor body in line with the #1 spark plug
pole on the distributor cap.
3) Remove the distributor cap. The rotor should be in line with the
mark on the distributor (this ensures that the rotor is directly below
the #1 pole on the cap when the coil fires). If it's not in line,
loosen the distributor clamp bolt and turn it until the rotor is in
line with the mark (ie: rotor is directly below #1 pole when engine is
at static timing mark).
4) Now, very slightly loosen the screw that holds the Crane optical
trigger to the distributor body. Slide it a bit so that the trigger is
just a bit clockwise of a slot in the shutter. Remove the high tension
lead (spark plug lead that goes from the coil to the distributor) from
the distributor cap and place it near a ground source, but safely from
you. Turn on the ignition, and ever-so-gently move the optical trigger
unit clockwise until you hear the spark click from the high tension
lead. Tighten the optical trigger unit down. You know have the spark
occuring at your desired static timing setting, with the rotor directly
in line with the #1 pole on the distributor cap.
5) To ensure that nothing slipped a bit, place the distributor cap back
on. Again, remove the high tension lead and place it near a ground
source. Turn the ignition on. Slacken the distributor clamp bolt a
bit. Turn the distributor a bit clockwise, then move it slowly
counterclockwise until you hear the click. Stop there and tighten the
clamp bolt. Remove the distributor cap and make sure the rotor is in
line with your #1 pole mark on the distributor.
Your Crane ignition unit is now properly phased to your distributor.
Tim Holbrook
1971 TR6
--- Sally or Dick Taylor <tr6taylor@webtv.net> wrote:
> Bob---It would be far better to get the car running well before
> complicating matters with an after market ignition.
> My interpretation of "phasing" is to be sure the tip of the rotor is
> right at the center of the distibutor cap's tower on the spark plug
> that's supposed to be firing. This can be determined by turning the
> engine over to where the crank pulley mark is right at Top Dead
> Center,
> #1 firing. At this time the rotor should be right at the tower wire
> that
> carries spark to #1 plug. Should the rotor be between two of the
> towers,
> the spark will have a choice of which tower to send the spark, taking
> the path of least resistance. The result would be an engine that
> sometimes fires at the wrong time, causing backfires and misfires.
> Excess slack in the train that drives the distributor rotor would be
> one
> such cause of being "out of phase". This might show up when using a
> timing light as a large variation or bouncing in timing. Check this
> at
> various rpms.
>
> Dick
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