MSD Ignition

[Roger Ball]

I put a pro billet distributer and a msd 6al ignition in a 69amx 343. I am trying to set the timing. I have it advanced 15 degrees & it runs good. Now I am trying to figure the advance adj. I have the heavy springs in now with no pinging. Should I go to the smaller springs and let it advance quiker?

[donsjave]

JUst installed the lighter springs in mine and it did make a big difference both in performance and fuel ecomony. It took me a while to get convinced that it would improve the performance and it did. The only difference is that I reset my timing to about 10-12 Degrees BTDC. I suffered no pinging and the thing goes like skunk. I'm told that the mechanical advance in the dst is about 18-20 degrees advanced and then you add for the vacum advance for about a total of 32 degrees total. I do not really know if this is true, but it does work. I was also told that you do not want more than about 38 degrees in total advance or you will suffer some problem that they did not explain. Anyway, get on it and long live AMC.

[Roger Ball]

I un hooked my vacum advance. I thought that was what you are suppose to do. I installed the lock out for it.

[donsjave]

Try hooking it up again and see if it makes any difference. All the lighter springs do is bring the advance in at different RPM's. Example: The lighter springs will bring the mechanical advance (inside the Dist.) in at lower RPM, at around 1500-1800 RPM's. This is supposely good for acelleration at the bottom end. The heavier springs will bring the advance in at around 4000 RPM. For performance in the lower end where most of us drive anyway it will not hurt the engine nor will it cause it to burn too lean. If you are after more power in the lower power curve, this is where you want to be.
When I tried this at first, I was somewhat hesitant because I did not know anything else. Got to remeber, I was raised at a time where everyone drove with the standard point system and some of them really sucked. So I learned on some pretty old stuff.