what is the difference between the Transistor Ignition coil and the points coil? Will the points coil work with TI?

 

Gene, my '69 had a points coil in it when I bought it.....It ran.
I changed it out to a TI coil and it seemed to start and idle better(might have been mental thing because it cost me a small fortune).
I have no idea what the difference is sorry.

Fiedler says it won't work.......mine did, what can I say.
http://www.tispecialty.com/articles/article4.htm

Jim

 

I'm unable to find my explanation sheet from Dave Fiedler which explains this difference. However in looking in Bizocco's book, he gives an explanation of the workings of the TI system over the conventional points system, and in his explanation, he states that the TI coil has a modified winding in the coil housing that projects an amplified, or surge voltage when receiving the signal from the amplifier thru the special harness. Apparently this coil can and does receive a much more intense signal over a conventional points coil.

 

K-66 Transistor is called a "brute force" system by Electrical Engineers (really early type of transistor switching design.) While a "points" type coil is allowed to saturate (current passing through primary coil windings while the points are closed) a K-66 coil is not charging until the transistors trigger and send voltage through coil then shuts off for secondary ignition firing (points open to cause the voltage breakdown in a conventional type of ignition system.) This requires a differnt type of winding for the K-66 coils (less windings) and the impedance (resistance) of a K-66 coil should be lower than a "points" type coil. Modern electronic ignitions ground the coil through the transistor which puts the electrical load through the device being triggered and the transistor GROUNDS the device instead of going through the transistor FIRST and THEN into the device like the K-66 system (the transistor is taking the full current load if the system wiring grounds before the device and this usually results in transistor failure or degradation of transistor performance.) You have to remember the transistor was invented in the late 1950's and there was a learning curve while it's applications were developed, the K-66 system was first availble in the 1964 model year and all the enginering was done in the early 1960's had it been released in 1969, the system would have been different in design. K-66 ignition systems should not be subjected to a ignition performance check used by "old school" mechanics that involves pulling the plug wires out of the distributor cap looking for RPM changes to diagnose week cylinders of a motor. Doing a cylinder "balance test" in the "old school" manner can result in excess current draw that will KILL the amplifier unit. What can be done instead is to insert copper wires into the distributor cap and ground the wires for a balance test. Another KILLER of K-66 amplifiers are leaky coil high tension leads that arc to the primary side of the ignition coil. The coil wire can be silicone sealed into the coil terminal to prevent this from happening (make sure the coil wire is fullly seated into the coil terminal before the silicone is dried.) The K-66 is a good ignition system and part of Corvette's leading edge technology heritiage and also one of my "litmus tests" for a 70-71 LT-1 Vette