Joe,
Getting familiar with how to properly set timing with points is a good thing
even if you are converting back to Crane XR700 that way you will know how to
set it up quickly in an emergency. As Dick Taylor said, getting it set at 10-12
degrees BTDC at the crank pulley at about 800-900 rpm is the most common
setting I have seen without vacuum retard connected and tube plugged for stock
engines. With vacuum retard connected again you will likely be in the 2-4
degrees
ATDC range at 800-900 rpm idle. It is key to keep the rpm idle below 1000rpm
to eliminate the centrifugal advance weights and springs coming into play.
Be aware that some timing lights have integral advance knobs (just in case
your buddy lets you borrow one and does not provide the manual). If you want to
see the actual advance on the crank pulley markings itself be sure to set the
knob to 0 degrees advance on the timing gun. There are ways to check the
distributor advance at higher rpms by then turning the advance knob on the
light
until the crank pulley flashes back at 0 degrees. Then you look at the timing
gun knob to read the advance created at that specific rpm. The advance curves
for STD dizzys are in the Bentley. The 0 degrees slot marked on the crank
pulley
is the easiest to "see" as it is so deep. Put some white paint or chalk on it
for easy viewing especially if you have painted the crank pulley (as I have)
and the other markings for BTDC and ATDC are much more faint.
My car came with the old Allison model (now Crane XR700) and I have yet to
install points but have some in the boot just in case. My experiences are that
the way you install the beam splitter and the photo diode have MANY
possibilities. Get the #1 cly. in firing position TDC by turning the crank.
When
installing the XR700 I would suggest getting the dizzy loosened and try to
center it
in the available travel CW and CWW then lock it down. Then assemble the leg
bracket to the dizzy plate in the middle of the slot. Then attach beam splitter
to the shaft. Then attach the diode to the leg bracket. Before tightening that
screw, align the center notch of the diode to the closest notch to the #1
spark plug terminal in the beam splitter. Then check to make sure that there is
clearance for the beam splitter to freely spin within the gap of the diode
emitter and receiver. You may have to adjust the height of the diode as you
want
that beam splitter to be in the middle of the gap between the lens.
Now you can put the rotor, cap, and wires on and give it a shot. Since you
firstly positioned the dizzy in the middle of its travel you now can fine tune
the timing with the light and spinning the dizzy a bit. If the available travel
of the dizzy is not enough to dial it in you will have to adjust the position
of the diode again on the leg bracket accordingly. Move the diode 2-3mm CW to
advance or CWW to retard then try again.
I did not think typing all this would be so long...sorry. Congratulations on
your new motor, I am jealous!
Michael Rankin
1971 TR6 CC 61212 L
Louisiana, USA
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