High Energy Ignition System W/O EST

Fig. 3 H.E.I. distributor components. Inline 4 cyl. units with external coil. 6 cylinder shown (4 cylinder similar):

NOTE: Since this is a full 12 volt system it does not require a resistance wire.

OPERATION
The HEI system, Fig. 1, utilizes an all-electronic module, pickup coil and timer core.
- The magnetic pickup consists of a rotating timer core attached to the distributor shaft, a stationary pole piece, permanent magnet and pickup coil.

When the distributor shaft rotates, the teeth of the timer core line up and pass the teeth of the pole piece inducing voltage in the pickup coil which signals the module to open the ignition coil primary circuit.
- Maximum inductance occurs at the moment the timer core teeth are lined up with the teeth on the pole piece.
- At the instant the timer core teeth start to pass the pole teeth the primary current decreases inducing a high voltage in the secondary winding which is directed through the rotor and high voltage leads to the spark plugs.

Vacuum Advance
The vacuum diaphragm is connected by linkage to the pole piece. When the diaphragm moves against spring pressure it rotates the pole piece allowing the poles to advance relative to the timer core.

Centrifugal Advance
The timer core is rotated about the shaft by conventional advance weights, thus providing centrifugal advance.

NOTE: A convenient tachometer connection is incorporated in the wiring connector on the side of the distributor cap, Fig. 1. However due to its transistorized design, the HEI system will not trigger some tachometers.

CAUTION: Never connect a wire directly between the "Tach" terminal, Fig. 1, of the distributor connector and ground since this will damage module circuitry.

NOTE: To adjust ignition timing connect timing light to the No. 1 spark plug secondary circuit.

CAUTION: Forcing foreign objects through the boot at the No. 1 terminal of the distributor cap will damage the boot and could cause engine misfiring.

CAUTION: The spark plug boot has been designed to form a tight seal around the spark plug and should be twisted 1/2 turn before removal--to avoid damaging the boot.