Yeah get the initial timing right first before you look to set idle mixture...... it will make that job so much easier and the motor will respond quickly to your mixture changes
what it was back in the day for 4 star style leaded petrol means nuffin with the current fuel
but its likely to have been a few degrees before TDC
if you time it to total advance of 34*
there is a good chance that your initial timing will still be ball park 5- 8* as the standard curve in an original dizzy will pull in 24* or more
...hence the hints from pete
you will probably need to take about half of the movement out of the armature that the rotor arm sits on, by limiting how far the weights swing out
but you won't know how much till you try.
to get mine right
it wanted 14 BTDC initial advance
and 28 total advance any more made no difference
so i had to mess with my dizzy to limit the advance so that it only pulled in 14* at the crank
i did this by clamping the drive in a vice
putting my timing disk so it fitted over the rotor arm mounting, on the top of the dizzy casing
put a pointer (lolly stick with welding wire taped on) into the cut out section of the rotor arm mount, aligned it with 0* and twisted it
initially i could twist it 14 degrees against the springs which equates to 28 degrees of advance for the motor. (so no way could i set initial at 14)
I wanted 7 degrees twist against my timing disk
to get 14 degrees mechanical advance in my dizzy
so i could have 28 total at 3000 rpm with 14 initial at 800 rpm. 14 initial + 14 in the dizzy = 28 at 3000+
my dizzy uses 2 round posts to act as the stop for the weights its a bosch below the plate with chrysler stuff above, an aussie one basically.
i just sleeved them in brass model makers pipe and filed a bit off until i got my advance
your dizzy, if its an original mopar one, will potentially have slots which you can solder/braze or weld up or you can use a disk from FBO to act as a limiter.
its a bit of a fiddle but worthwhile
to get this done by a shop is £100+
an hours work + a load of pennies for their expertise.
this gets you 95% there. the last step is to choose the right springs... i never bothered i was quite happy
try to limit it so there is still tension on the springs so they don't fire off
it dumps in what advance it has by about 2500 rpm
and 14 * initial for my motor means no stinky tail pipe at idle.
i just need to sort the rest out now
other methods exist. you could plumb in the vacuum advance to manifold vacuum to put in advance at idle only....but i didn't want to..... the method has been explained to me by blue and the proof is sitting in morgan's engine bay (and many others) but as an awkward begger i didn't want to do it that way
mainly becasue i didn't have a problem with advance anywhere else i just needed more initial
in fact my car runs ok locked at 15..not as good as it can but you know.... feels OK
Dave