Phil---A dwell angle between 33 and 36 degrees is well within the
operating limit. Since either of the two readings is OK, then 'bouncing'
between them should not be noticable in the driving. The point gap, as
you know, must also be varying. This will show up with a timing light on
the front pulley, and you'll want to be sure the engine stays in time,
within reason. With no vacuum pulling on it, this should be somewhere
between 4 to 12 deg. BTDC at idle.
Near as I can figure, it would take a cam wobble of near .020 before the
rotor tip would strike any distributor cap tower. To be sure this isn't
happening, you can mark the edge of the rotor with a marking pen to test
this. Caps and rotor dimensions can be different among manufacturers.
Several options are available, should you choose to correct this
condition.
1) A new distributor. Ka-ching!
2) Replace the bushing$. (It should be noted that a bent shaft up near
the cam will also cause timing fluctuation, even with new bushings or in
a new distributor)
3) A magnetic or optical triggering mechanism, which takes all
of this out of the picture. These are advertised in the catalogues by
some Triumph parts houses.
4) Many of the new electronic ignitions that control dwell from within
their circuitry. MSD, and possibly Crane.
Altho I also have bounce in my points distributor, which shows up on the
timing pulley, my dwell meter never showed any variation. If I set the
points at .012 I could expect the dwell to stay steady at 37 deg.
Perhaps the Craftsman 'meter has a feature that steadies the needle, or
is just slow? Dan?
So far as maintenance on the distributor, I don't recall seeing anything
but squirting some oil in the centrifugal weights area now and then.
You can get grease to the internal bushings with some effort, and it
does require disassembly. I recall packing these bushings with wheel
bearing grease some years ago. It took most of the bounce out as
indicated at the timing pulley, but this didn't last for very long.
Dick T.
'73
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