I just got done helping another board member 'recurve his distributor', he had the MP slant six EI distributor...but... we couldn't get his car to idle reliably under 1200 rpm... on further inspection we found the single spring was too light, and the curve was 'all in by 1200' which makes for a good drag curve, but kinda hard to keep it idling good at the stop light, and it wanted to ping occasionally....

FYI for those who can't get one but wish to 'clone' one from a remanf unit:

Typical 70's EI body, with stock advance weights, uses only one single 'blue' spring. The governor is stamped 11R (22 degrees of mechanical advance). The vacuum pod was stamped for 17-18 degrees of advance, when we plugged it in it advanced up to 20 degrees....

The mechanical curve dialed in 22 degrees of advance at 1200, vacuum came in at 10"Hg for 20 degrees of advance, 12" HG for 8 degrees, then 2 degrees at 5" Hg...

The governor slots: start at 7mm from the outer edge of the shaft retainer, are 1cm long, and terminate at 6mm from the end of the 'paddle'. (Sorry they are in metric, but those were 'dead on' with my caliper than trying to get a fractional inch that was close enough...)

final calcs seem to indicate that it was supposed to be used for 10 BTDC initial, 22 mechanical advance for 32 total, then 20 degrees of vacuum advance for 52 degrees on highway/low load use....

Sadly during timing I found that the stock unit caused a 10 degree 'waver' in timing at 800-1200 (timing mark would jump to each side of TDC on the dial back by 5 degrees max each side, and the idle would get a bit 'chuggy')...

I added another blue spring which changed the timing characteristics to:
Mechanical adv. same, but is all in by 2300 (typical street shift point for manual tranny users)....
Ran out of time to try the new combo, it's very similar to the homemade unit I cobbled up like Slant Cecil covered in his post not too long back...will let you know more when we get in installed and get some test runs in....

Hope that info helps out since kits are now up to $300 each, and remanfs and a die grinder is only $75....($30 +$45...)

-D.Idiot

I have to admit. Dist timing is probably the thing I understand the least about my car. I understand the basic concepts but the subtle effects of advance curve escape me.

I have a fairly mean slant. Probably 210hp at the flywheel. Isky 448 lift cam. 400cfm AFB on an offenhauser intake and Clifford 6x2 shortys. MOPAR Performance ignition that's probably 10 years old. It's a 3.09 first four speed car with 3.23 open gears.

I've never messed with the distributor other than setting the timing. I do have it set to all in at 32 deg. It seems to run pretty good. I wonder if there's hidden power in the timing curve.

I'm about to put on triple DCOE carbs. No more Vacuum advance. How does that effect the timing? any suggestions?

Mike

_________________
1965 Valiant 200 /6 2dr Sedan.
1965 Valiant 200 V8 4dr Wagon
1965 Barracuda /6
1965 Valiant Convertible V8