Dis8-Chevy Distributorless Ignition System For Small Block & Big Block Chevy PDF Installation Manual

The Compu-Tronix Distributorless Ignition System is a “waste spark” type ignition system. The spark events are controlled by the Mechanical Trigger Device and Electronic Control Module (ECM). The spark plugs are fired directly from a pair of high energy coil packs. Each coil pack has two internal coils making for a total of four coils. Each individual coil has two terminals that provide spark output to two cylinders.

In a waste spark type ignition system, each cylinder is partnered with another cylinder that is phased 360° apart from it. This means both cylinders are at Top Dead Center (TDC) at the same time; one cylinder is
at TDC compression while the other is at TDC exhaust. Each coil has two output terminals; one for each of the paired, out of phase, cylinders.

When the ECM commands the coil packs to fire, an individual coil will provide spark to both of the paired cylinders. The spent gases in the cylinder at TDC exhaust act as a conductor and very little spark energy
(1% of total available) is used to jump the plug gap. Thus, a spark is being “wasted” on the cylinder that’s on the exhaust stroke. The compressed air and fuel in the cylinder at TDC compression create a very
high resistance thus requiring more spark energy (99% of total available) to jump the plug gap. This creates a very high spark that burns hot and has a long duration.

The Compu-Tronix Distributorless Ignition System uses a series of Hall Effect sensors and a flying magnet trigger disk to trigger the ignition events. The ECM uses an advanced digital controller to manage an adaptive dwell system. By controlling dwell, the high energy coil packs maintain optimum spark energy output throughout the entire rpm range.

1. Remove the wire from the ignition coil primary negative (-) terminal.
CAUTION: MAKE SURE THE IGNITION SWITCH IS OFF!! The wire from the ignition switch to the ignition coil primary terminal is NOT fused in many applications. If this wire is allowed to touch vehicle or engine ground, with the ignition switch on, it can cause a direct short on the battery
possibly causing permanent damage to the vehicle wiring and a fire. Cypress Engineering assumes no liability for damage caused from this occurrence or due to any faults in the existing vehicle wiring.
2. Remove the ignition switch wire from the ignition coil primary positive (+) terminal. Make sure this wire does not come into contact with vehicle or engine ground. 3. Disconnect the coil to distributor high voltage wire and remove the ignition coil and mounting hardware.
4. Disconnect all high voltage spark plug wires from the spark plugs. Remove the distributor cap and set it aside.

Download Dis8-Chevy Distributorless Ignition System For Small Block & Big Block Chevy PDF Installation Manual