Ford Muscle Cars Tech Forum banner

1 - 5 of 5 Posts

·
Premium Member
Joined
·
86 Posts
Discussion Starter #1
Ok, these may be stupid questions, but I've always wondered how a few aspects of MSD and other aftermarket ignition systems work.

1. How do the little timing retard knobs work? I can see how something like that would work on a DIS application, but I don't get how it works with a distributor... No matter what you do to the electronics, the rotor is still going to reach each terminal on the cap at a certain time, right? Someone enlighten me!

2. Also, how do some of the systems (like the Digital 6 Plus for example) give 20 degrees of spark duration under certain conditions? How do you get spark for a longer duration than the rotor touches the terminal on the cap?

These are probably very simple answers, but I've been unable to figure it out in my head, so please, share yor expertise.

-Brian
 

·
Premium Member
Joined
·
2,216 Posts
The MSD(or whatever) is wired to the coil and the distributor so it knows when the distributor wants the coil to fire. In the old days that was controlled by the points closing. Newer electronic distributors either have an optical sensor or a magnetic pickup that sends the MSD a signal to fire the coil. Since the MSD is now controlling the spark it can add in extra timing delays or take them back out based on the distributor's signal.




<font size=-1>[ This Message was edited by: Hottarod on 12/24/01 3:32pm ]</font>
 

·
Premium Member
Joined
·
86 Posts
Discussion Starter #3
Thanks for the clarification. I kind of figured that it was just jumping from the rotor to the cap, but I wasn't exactly sure.

-Brian
 

·
Premium Member
Joined
·
2,216 Posts
Sorry, I got a little carried away(too many years working on computers). No it was the points in the distributor that told the coil when to fire.
 
1 - 5 of 5 Posts
Top