View Single Post
  #69   IP: 24.152.131.220
Old 09-28-2011, 09:57 PM
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
Incomplete data because I have CRS syndrome

Got the ballast resistor installed today and took some coil temperature measurements. This report is incomplete because I forgot to take my voltage tester and camera.

I think I'll post a complete report on a new thread at a later time but for now here's what I can tell you:

I made 2 independent sets of temperature measurements 2 weeks apart. One set was with the original ignition set-up - Pertronix EI and their #40511 Flamethrower coil. Measurements were made from a dead cold start and targeted the Flamethrower label on the coil. RPM was 1200 to bring the alternator into play.

The second set of temps were measured exactly the same except with a ballast resistor installed. The resistor was the only difference.

Without resistor the coil temp achieved 162 degrees in 30 minutes.
With resistor - 133 degrees in 30 minutes.

I don't know if either temp maxed out in 30 minutes although the with-resistor temps were rising at a lower rate than the no-resistor by a factor of 1:4 at the 30 minute mark. That may imply the with-resistor temps were approaching max while the no-resistor temps were not. More measurements with longer run times will tell us more.

And finally, there was a thought that the resistor and resultant lower coil voltage may have a negative effect on starting. That was not my experience. My engine fired up in it's normal 1/2 second crank, no noticeable difference at all.
__________________
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; 09-28-2011 at 10:48 PM.
Reply With Quote