Q about timming, vac advance on duraspark

[karfer67]

ok got a few questions here. first a little about my setup. i have a 62 ranchero with a 200, 3spd, 8"rear. for the ignition it is a duraspark which i have always loved how fast it fires up and runs ok. currently i have my plugs autolite 46 gaped to .055 and initial timming at 7 BTC.
it has always had an issue when after a long drive then stoping (like say at a gas station turning the engine off) then when restarting it will pop and stumble through the exhaust for a long time after that. off idle was ok but in gear coasting again pop through the exhaust. i had read a few posts around here about disconecting the vac advance so i figured what the heck and WOW no more poping it is like night and day.
HERE is the question a friend of mine thinks that i should advance the initial timming now but i am not sure. any suggestions?

 

[bigcatchdaniel555]

Sounds like a good place to start even though the factory calls for about 6 degrees timing these motors usually enjoy 12-14.

 

[fordconvert]

Where do you have the vacuum line hooked? Manifold? Ported? SCV?

Having the vacuum advance (may be better to think of it as a retard under load) generally gives you better throttle response because you can run a bit more advance either in base or mechanical. Also helps the idle and temps if its manifold vac. Some of the factory systems used a thermal switch to switch the vacuum source between manifold and ported based on temp. You may be able to find such a switch that would switch at the temp to help you in that high underhood temp situation.

 

[JT81stang]

If you've decided not to use the vacuum advance and if that distrubutor has not been modified internally (i.e. lighter springs put in) than advancing the initial timing to 12-14 degrees is fine.

 

[JackFish]

Factory gap on my '78 is .50. I don't know if that would make a difference but it might be worth a try.

 

[63comet]

Something I found out about DII's, I could not understand why I could not run any initial advanced timing to speak of, due to the fact my engine would ping and run very hot. After changing the radiator to a 3 core and playing with the vacuum to the distributor and trying everything under the sun to get it to stop pinging, I just set it at TDC and left it there. This winter when I decided to rebuild the motor and fix the Dizzy gear, I decided to order the DII advance kit from Mr. Gasket and recurve the Dizzy. When I took the dizzy apart, I found out that the advance was set at the 18* slot, the other was a 13* slot, giving me 36* without any initial dialed in at all, I took apart a couple of old dizzy's I had and found a shaft with a 10* and a 13*. so I set the dizzy up with the 10* slot and installed the lighter springs. I'm hoping that this will take care of the pinging and high heat, I have not run the car yet, but I have fired it up and broke in the new cam and gears. and it sounds real good. Mypoint being if you do not know what the setting is, it is hard to determine how much initial to put in since you probably want around 35*-38* total timing.