So any voltage under 14 or so won’t hurt the coil?The voltage the alternator puts out can go up to 14.5 volts or thereabouts.
It depends on what is drawing current and the state of charge in the battery.
View attachment 725830 I am installing a new MSD distributor ready to run in my 70 Belvedere with a 440. I have removed the electronic ignition, ballast, etc. and just have a standard points wiring set up (as pictured). However I am getting 13.4 V at the coil when the engine is running, and 11.8 when the engine is off but in the run position. Doesn’t that mean the voltage regulator is bad? The engine has never ran better, but I want to confirm that voltage before driving it.
That's down right shocking...I run an MSD "ready to run" model on the Mopar big block in my drag boat. When you remove the factory setup, you no longer have a resistance circuit. MSD prefers to see at least 12.5 vdc. The higher voltage is not an issue. It will vary between 13-14.5 vdc. I like the Mopar electronic ignition and run that in my car. But do a spark test on your MSD with an HP coil.
hehehe ;)
13.2 volts is the accepted minimum for a battery under charge condition.So any voltage under 14 or so won’t hurt the coil?
I've been zapped by an ignition coil a few times over my years...That's down right shocking...
Having 13+ volts at the coil is fine because the coil just steps up the input volts to about 20 to 40 thousand output volts. The coil really doesn't care if you have 7 volts or 14 volts. However, you care because lower volts means it takes longer to get fully charged and it also means more watts/amps must be pushed to met the demand over lower volts and that burns up undersized wiring.
The ballast resistor was there to protect old point style distributor because 7v made less of a spark than 12v. The design starts to have issues over 5k RPMs because the coil can't fully charge before the next spark request.
Funny story, last years I had my ballast resistor backward which meant I was getting just 5 volts to the coil. The resulted in my engine was falling on it face over 4,500 rpms. Fun times!
I run an MSD "ready to run" model on the Mopar big block in my drag boat.
I run an MSD "ready to run" model on the Mopar big block in my drag boat. When you remove the factory setup, you no longer have a resistance circuit. MSD prefers to see at least 12.5 vdc. The higher voltage is not an issue. It will vary between 13-14.5 vdc. I like the Mopar electronic ignition and run that in my car. But do a spark test on your MSD with an HP coil.
hehehe ;)
V-drive 1968 Raysoncraft. No trans, just start and go.Outdrives or jet?