What Distributor set Timing do you use with Pertronix on a 390?

[Jack Miller CLC# 24441]

Hi All,

I tried using what the factory manual said to set the timing to but I am using Pertronix.
Using  the factory setting, I am getting hesitation. I put it ahead a bit and played with it but it still is not how a Caddy should run off the start. I am getting a bit of hesitation.
Has anyone had any issues here or can throw a degree at me that I can try?

Thanks
Jack
1961 Series 62 Convertible

[62droptop]

when you installed the pertronix, did you run a 12 power source for the coil,or are you still using the resisted factory wire?
if you are using the resistor wire,your module will not be getting the 12v it requires

also are you using the stock coil or a pertronix coil?

[Dave Shepherd]

The swap to Pertronix does not change base timing setings, the hesitation is from another issue.

[TJ Hopland]

The couple of pertronix kits I have installed without removing or touching the distributor body (base setting) have shifted the timing a few degrees.  I think one went back about 3 and the other one went advanced a few both were on the same model engines. 

These may be obvious things you have already covered but I figure I will mention pretty much all the stuff I have run into or missed myself when working with these types of issues.

Are the weights and springs all in in good working condition?  How about the vacuum advance and overall vacuum line condition on the whole car?   Have you had a good look at the harmonic balancer (Im assuming that is where the timing mark is on this engine) to be sure it has not slipped and the mark is off?   Are you reading the gauge on the engine correctly?  Perhaps its a little dirty and you are assuming where the numbers are?   Sure you are connected to the correct plug wire ideally close to the plug?  IF you connect near the distributor and other wires sometimes the inductive pickups can pick up a signal from another wire.   Are you using a tach to be sure you are trying to set it at the proper rpms?  I have run into cars that pull the advance in at a pretty low rpm so if the idle is a little high you wont be getting the base in the correct place.   

The kit should not change what the engine wants or the curves assuming you did not do anything with the rest of the system. Often times the weights can stick and just being in there knocks them loose so its possible that things were not working correctly before you installed the kit.   If they were stuck the base setting could have been changed to compensate for it or some other adjustments could have been made and that is why the car appeared to run better before you messed with it.

I leaned the hard way many years ago that anytime I am messing with the distributor on a running engine that the first thing to do is get out your timing tools and take some readings.  This would include a dwell meter if its a points system.  Take readings at idle and various rpms with the advance connected then again without it.   This tells you how it was running before you started and if the weights and vacuum appear to be working.   Even if the balancer and or timing marks are not correct this still gives you a reference to settings that the engine will run at.   If after you change parts it runs worse you can then go back to what did work.   If the engine was not running before I had to mess with it I at least make physical marks on the position of things and  their apparent condition.

[Dave Shepherd]

The couple of pertronix kits I have installed without removing or touching the distributor body (base setting) have shifted the timing a few degrees.  I think one went back about 3 and the other one went advanced a few both were on the same model engines. 

These may be obvious things you have already covered but I figure I will mention pretty much all the stuff I have run into or missed myself when working with these types of issues.

Are the weights and springs all in in good working condition?  How about the vacuum advance and overall vacuum line condition on the whole car?   Have you had a good look at the harmonic balancer (Im assuming that is where the timing mark is on this engine) to be sure it has not slipped and the mark is off?   Are you reading the gauge on the engine correctly?  Perhaps its a little dirty and you are assuming where the numbers are?   Sure you are connected to the correct plug wire ideally close to the plug?  IF you connect near the distributor and other wires sometimes the inductive pickups can pick up a signal from another wire.   Are you using a tach to be sure you are trying to set it at the proper rpms?  I have run into cars that pull the advance in at a pretty low rpm so if the idle is a little high you wont be getting the base in the correct place.   

The kit should not change what the engine wants or the curves assuming you did not do anything with the rest of the system. Often times the weights can stick and just being in there knocks them loose so its possible that things were not working correctly before you installed the kit.   If they were stuck the base setting could have been changed to compensate for it or some other adjustments could have been made and that is why the car appeared to run better before you messed with it.

I leaned the hard way many years ago that anytime I am messing with the distributor on a running engine that the first thing to do is get out your timing tools and take some readings.  This would include a dwell meter if its a points system.  Take readings at idle and various rpms with the advance connected then again without it.   This tells you how it was running before you started and if the weights and vacuum appear to be working.   Even if the balancer and or timing marks are not correct this still gives you a reference to settings that the engine will run at.   If after you change parts it runs worse you can then go back to what did work.   If the engine was not running before I had to mess with it I at least make physical marks on the position of things and  their apparent condition.

TJ, on the money!!

["Cadillac Kid" Greg Surfas 15364]

Jack,
The Pertronix I have installed proved to be rather sensitive to the "clearance" specs.  I knows it can be a pain to pull the kit apart to add the shims they give you to adjust this clearance, but you have to do it to get them to run right.  A lot of other good tips here be sure your wiring is correct (to 12 volt sourcde) and you have a good ground to the advance plate.  The timing is the timing, and you should run the same as with points.
Greg Surfas