Pagoda SL Group

W113 Pagoda SL Group => Drive train, fuel, suspension, steering & brakes => Topic started by: bracurrie on January 21, 2020, 16:19:31

Title: Spark with or without transistorized ignition
Post by: bracurrie on January 21, 2020, 16:19:31
Contemplating installing a 123 dizzy on my M130 where it has a transistorized ignition. Besides the lower current through the points does the ICM also provide a hotter spark?
If installing a 123 can you keep the hotter spark?
Brad
Title: Re: Spark with or without transistorized ignition
Post by: jeffc280sl on January 21, 2020, 17:58:48
I think you will find your answer here.

https://www.sl113.org/wiki/Electrical/TransistorIgnition

Generally speaking the ignition coil determines a hotter or cooler spark plug current
Title: Re: Spark with or without transistorized ignition
Post by: bracurrie on January 21, 2020, 18:33:20
Very good write up on the transistorized ignition. I had read that before but it doesn't really say that the spark is hotter, through I know it is.  However, I will reach out to 123 and see if the transistorized system and the hot spark can stay when the system is installed. Brad
Title: Re: Spark with or without transistorized ignition
Post by: jeffc280sl on January 21, 2020, 19:54:18
Please look at the attached simplified picture of a transistorized ignition system.  The ignition components sit on one side of the coil. It provides a low voltage pulse to the coil where it is amplified/multiplied and sent to the distributor.  The distributor does what its name implies and takes the high voltage input from the coil and sends it to the spark plugs.   There are various coils available for our cars to provide hot or cooler high voltage inputs to the distributor.  I believe I have the bosch blue coil on my car.
Title: Re: Spark with or without transistorized ignition
Post by: Tyler S on January 21, 2020, 20:45:45
The transistorized ignition is just that. A transistor that acts as a set of points to switch the coil on and off and in turn puts less wear and stress on the points in the distributor. The 123 has its own transistor and optical pickup built in so you would not keep the original transistor ignition box connected as there would no longer be points or a signal for it to use. Another member successfully  kept the speed relay and emissions gear intact and functional using a resistor in series from the coil. See post:#19 of link below.
https://www.sl113.org/forums/index.php?topic=29725.msg215309#msg215309
Title: Re: Spark with or without transistorized ignition
Post by: Shvegel on January 21, 2020, 22:40:31
Save all old parts.  Very tough to find.  I ended up having to fabricate the ignition box mount under the battery because the only person that had one wanted $300 just for the piece of bent sheet metal.
Title: Re: Spark with or without transistorized ignition
Post by: bracurrie on January 23, 2020, 15:44:27
The transistorized ignition is just that. A transistor that acts as a set of points to switch the coil on and off and in turn puts less wear and stress on the points in the distributor. The 123 has its own transistor and optical pickup built in so you would not keep the original transistor ignition box connected as there would no longer be points or a signal for it to use. Another member successfully  kept the speed relay and emissions gear intact and functional using a resistor in series from the coil. See post:#19 of link below.
https://www.sl113.org/forums/index.php?topic=29725.msg215309#msg215309
Coming into focus for this amateur here. Shame I bought another ICM when I won't need it after installing 123 dizzy.
What I am unsure about now is maintaining hotter spark that the ICM facilitates on the OEM setup. 
Title: Re: Spark with or without transistorized ignition
Post by: Tyler S on January 25, 2020, 19:37:22
Brad, get yourself a high output coil to pair with the 123 and it will surpass the factory Ignition system. Remember its the coil doing all the work. The distributor/ICM is just the component controlling it. The 123ignition website has a few options they recommend.
I have a Bosch red coil paired with my 123. There is a “flame thrower” coil that outputs 40kv. I have this coil installed in my 1936 Ford Flathead. Couldn’t be happier.
Title: Re: Spark with or without transistorized ignition
Post by: bracurrie on January 26, 2020, 19:28:35
Tyler,
Thank you for the reply. I plan on trying the coil that I already have when I get a 123.
Brad