Hi

Just checked the rotor moved cw about 1/4 of a turn thats all hard to move.

My RPM at Idle was 800 rpm vac plugged the dial on the timing light was at 23 when it hit zero on damper,

describe the 1/4 turn? If the rotor is at 12 o'clock how far will it turn? Even w the heavy sp w the long loop still in there at that rpm, 3500 right? I'm still not grasping why only 5 deg of mech adv. What springs are in it?

Ok

The rotor tip facing back moved 1/4 inch very little

The have the 2 new springs in it now very thin the heavy one is in the box

with initial 18 vac plugged ran engine uo to 3500 dialed timing light dial to 35 would not go to zero on the damper. When i went up with the dial like 36 37 38 39 40 the zero on damper was getting father away. when i went down it started moving towards zero when it got to 23 it was at zero tdc

I never noticed the actual ballpark distance on that but I'm thinking it should move more than 1/4". All you posted is correct. I'd loosen the dist clamp & turn the housing so you can see down past the 2 plates to check both slots & see if the pins are not hung up or the slots have not been welded up as you twist the rotor again & you'll have to turn the housing to 2 different places to check both slots and as you know you'll need to retime when your done. If nothing is obvious you may have to take off/out the reluctor/plates again. EDIT I checked my '67 "Glenns" manual & no 340 that early but every dist I saw has way more than 5 deg mechanical (slots) so we're missing something right in front of us

I pulled the dist apart torn it down check everything the slots are clear and the pins are moving freely. I can pull on both weights and they move ok and so does the springs.

We may need to lengthen the slots as we need to get to 35. The 23 as is, is killing the cyl psi

hould I look for another dist.? Mech or Vac This is a stock dist been around for awhile. what would be a good Dist to look for, using a point dist with a pertronix 2 inside what do you think

lets work w what we have. Want vac adv. look at the chart in the archives for how long to file the slots to & use a rattail file to elongate yours. If you are comfortable w 18 initial then want ~8.5 dist degrees to give 17 more at the crank. reportedly the archive chart is close but not dead on so go a bit less to start w and I'm sure the springs will need to be changed so you will be back in there and you can grind the "tips" of the weights to slow the curve after you get the total set in lieu of sourceing a heavier spring as 2 light MP ones MAY be too fast as is but the subsystems must b done in order. initial/total/springs/vac adv

Do you still have the distributor apart? In a Chrysler built distributor there is s number stamped near the advance slots (underneath). Multiply by two will be crankshaft degrees. Look at the slots and seee if someone welded or brazed up the slots.

With the distributor apart, but springs and weights installed, push on the wieght with the light spring as if its was moving out with centrificgal force. It should rotate the slot armature unil the loop of the long spring has no slack. There should still be a 1/3 to just a little bit of the slot left at that point. On some mopar high porformance distributors the heavy spring lets the advance continue very slowly preventing bounce and offseting any retard caused by stretching and twisting components. This is how the mechanical tach drive distributors were made. On a more run of the mill distributor, the heavy spring just shaped the advance curve.

Based on the specs you've given, everything else seems pretty good. I ran 340 with comcams HE280, 9 something compression and singleplane street dominator, and yes a 3310 on top. Now I'm running a similar engine with the LD340. 18 degrees is a good ballpark initial and 34 or so is a good initial target for 2800+ rpm. One thing I didnt notice was if you had a 4 speed or 727. I used a torque converter with 3000 stall. I've had that reduced to 2700 or so and its not as good - much harder to dial in the timing and carb especially with the 10% ethenal mixed gasoline. I'd say a high stall TC is required for your combo just as it was for mine (or higher gears, or , or or )

Cheap way is find used (in good shape) or parts store rebuild. Or if yours is in good shape then just finda few others so you can take parts out (and get the slots you want). The MP distributors used to be a good bang for the buck but not sure how that will work out with the Pertronix.

Good Morning

Ok on the slots there's a R15. When i open my weights the pins go all the way to the end towards the weight.There's no room at end of slot. Pin goes all the way. Weight's are almost touching inside of case.The slot bar does not rotate stays straight.Really not alot of room in there. But for sure there's no room at end of slot. Kevin

I found another point Dist in the shop. This one has R19 on the bar with the slots. Alot of slop in the shaft. I noticed that these slots point down at the end not completey straight like the first one. Any Idea's Also have a couple electronic Dist not sure if they would would. I changed to pertronixs because my orange box burnrd out and decided to change dont know if that was a good idea or not. Kevin

Slots: Slots are often at a slight angle. Thats OK.
Length: 15x 2 = 30 degrees of advance (distrinbutor turns at half the crank speed, I wrote it down backwords above)
Weights clearance to body: Yup - its small. Just make sure there is no wobble that would let them hit!

OK: It sounds like you found the problem. If I understand correctly..
Are both of the springs are loose when the weights are pushed in? That is, when the pins rest against the begining of the slots, is either spring helping hold it in?

Even if the the light spring is providing a little bit of pressure, what may be happening is that by idle rpm, lets say 500 for simplicity, the mechanism has already advanced 25 degrees. Now there's only 5 degrees left in the slots. Setting the initial timing of 18 at idle, the distributor advance then tops out at 23 degrees. It probably hits 23 by 1500 rpm.

Take the other distributor apart and see if you can figure out why the springs in #1 dizzy are not coming into action as they should. Wrong springs for this application, or someone bent the loops, or something.

When set up correctly, the light spring should be strong enough to keep the weights from moving out unitl 700 - 800 rpm or even a little higher.

Exception is the old Direct Connection setup where they purposely used a super light spring with that long looped super heavy spring. Made it near impossible to set timing at idle. Timing was set at 'full' and everything at lower speed was just accepted for whatever it was.

You could use a similar approach to get around shortening the slots. But whether you do that or braze up/weld the slots, you first need to get both springs to help restrain the weights.

When you think you have it figureed out, install and measure the timing at 100 or 250 rpm intervals all the way until it stops advancing. If its going about 2500 or so, feel free to make it 500 or 1000 rpm intervals. be careful!

Put the R19 plate in & the diff angle of the slots is normal & when you do measure how long the slots are on the 1 you take out

I *think* the advance mechanism, weights, springs are interechangabel with the electronic distributors. Exception will be the later Mopar Performance version made by Mallory. (see some pictures on my website).

Well if you're OK with a ECU box, you could go back to the electronic distributor. You can use a parts store ECU for more reliability - or at least keep it as back up for one of the Street MP ECUs.
You're engine is such that a multi-spark, capacitive discharge ignition may be worth the expense. If you go with an MSD 6A, 6T, or 6C any of the distribuors you already have will work. You'll need a matching coil. Of course you'll still need to get the advance curve, so it only solves your current problem if you buy one of the more easily adjustable distributors.

edit: Its a time-money equation only you can answer. My inclination is to figure this out and get running.

I think I may have it, Your idle is 800 and the double MP light springs start advancing at ~600 so I think you're already into the slots at idle & if this is correct no wonder only 5 deg of mech was left. How about trying this, use the orig OE light spring plus the orig OE light spring from the dist you found (2 OE light springs) plus keep your current plate. this'll start at ~900 which is above your 800 idle. set the initial back to where it was, 18 right? then run it up & see what your total is (vac adv plugged as always) and at what RPM (for reference) it maxes out at

Ok

Will use the plate with the straight slots not bent at the end.??? Ok

Will take the smaller spring off the dist i found and use the smaller spring off the first Dist. I have the new ones i just got how about them. I cleaned everything up. Wait for your reply. By using the plate i've been using I've put 2 new springs light on that already ended up at 23. So your saying use the light springs that were in Dist I got ya just making sure kevin