View Single Post
  #1   IP: 24.152.131.155
Old 10-20-2011, 07:51 AM
ndutton's Avatar
ndutton ndutton is offline
Afourian MVP
 
Join Date: May 2009
Location: Torrance, CA
Posts: 9,619
Thanks: 198
Thanked 2,208 Times in 1,425 Posts
Electronic Ignition

Here are a few notes on Pertronix electronic ignition systems and their effect on coils. It's neither a drawing nor a schematic but I repeated it here to make the resistor calculator easier to find.:

Through testing and following an advisory from Pertronix regarding a 4 amp system maximum we found the addition of a ballast resistor in the ignition primary circuit significantly reduced coil heat in some cases. Internal coil resistance combined with coil input voltage were found to be consistent predictors of coil heat and subsequent failure. There is no indication a resistor will fix a sick coil. If your coil has overheated to a point of shut down, it's damaged internally and needs replacement.

We now have a simple ballast resistor calculator specific to the Atomic 4 with Pertronix electronic ignition. It applies what we've learned on the lengthy Coil Input Information thread and adds a 15% safety factor. You need to input two values, it provides a resistor value to one decimal place. Note that this is the best information we have at this time. Should new info emerge, we'll adjust the calculation as necessary.

Ballast Resistor Calculator.xls

For those unable to open the calculator or without Excel, smosher provided a free program to resolve the issue found here.
__________________
Neil
1977 Catalina 30
San Pedro, California
prior boats 1987 Westsail 32, 1970 Catalina 22
Had my hands in a few others

Last edited by ndutton; 11-29-2011 at 09:14 AM.
Reply With Quote
The Following 4 Users Say Thank You to ndutton For This Useful Post:
bigoledave (06-11-2022), C&C32 (03-18-2021), HalcyonS (04-06-2016), TimBSmith (10-03-2022)