Quote: ...but somewhere around '63-ish GM made the K66 transistorized setup available across several brands, which would be comparable to an MSD setup...it's a pretty slick setup, and was standard on the ZL1s/L88s, but was very prevalent in the C2/C3 'Vettes.
Tech Info on the K66.. for educational purposes only
BACKGROUND & OPERATION
In 1962 the Delco-Remy Division of General Motors began the task of designing an ignition system that overcame the limitations of the conventional breaker-point system. The overall objective of the new Delcotronic Transistor-Controlled Magnetic Pulse-Type Ignition System (the official name) was to provide long life, high reliability, and require no periodic maintenance during the life of the vehicle. Delco-Remy was successful in designing and manufacturing an ignition system that was superior to the conventional system and it continued to be superior for almost two decades.
To quote a Society of Automotive Engineers paper dated 1963 (after the system was developed):"The new Delcotronic Transistor Controlled magnetic pulse-type ignition system provides long maintenance-free life and high reliability which have been sought for many years. It accomplishes this end by totally eliminating the components which traditionally have been most subject to inaccuracy, wear, and deterioration."
The accomplishment of Delco-Remy's goals were made possible largely by the elimination of the familiar contact point set and substituting a magnetic triggering device. This solid-state device composed of a stationary magnetic pickup assembly and a rotating pole piece, provided an excellent signal to trigger the Transistorized Ignition (TI) system.
In order to fire each spark plug, it is necessary to induce a high voltage in the ignition coil secondary winding by opening the circuit to the coil primary winding. In conventional systems, this is accomplished by opening the distributor contact points. In the TI system, this is accomplished by inducing a voltage pulse in the distributor pickup coil which is conducted to the pulse amplifier where it signals a "triggering" transistor to turn off a "switching" transistor. This action interrupts ignition primary current flow, inducing high voltage in the secondary ignition circuit. The pulse amplifier does this opening of the circuit in a more efficient manner, which in part explains the improved performance of the TI system. In addition, while contact point deterioration problems limit primary current in the conventional system to about 4.5 amps, the TI system can operate as high as 8 amps which further enhances the performance of the system.
The Deltronic ignition system (now more commonly referred to as Transistorized Ignition or TI) overcomes all of the previously mentioned limitations of the conventional system because TI:
1. Will yield higher spark plug voltage. 2. Will operate at extremely high speeds without losing ignition performance. 3. Is essentially maintenance free.
An example of the TI system superiority can be seen when looking at the output voltage at the spark plug versus the speed of the vehicle. At 10 mph a conventional system is developing 24,000 volts versus 25,000 for the TI. However, at 100 mph the conventional system is down to 17,000 volts and the TI is at 24,000, which is 40% more voltage to fire the fuel/air mixture under high load conditions. In addition to this, the system will still function properly at speeds exceeding 9,000 rpm.
Chevy infiltrator 12.34 @ 109.45 with a 1.73 sixty foot
